CALL TRADITIONS AND DIALECTS OF KILLER WHALES (ORCINUS ORCA) IN BRITISH COLUMBIA by JOHN KENNETH BAKER FORD BSc (Honours), U n i v e r s i t y of B r i t i s h C olumbia, 1976 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n THE FACULTY OF GRADUATE STUDIES (Department of Zoology) We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA 30 November 1984 © John Kenneth Baker F o r d , 1984 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. I t i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of 2^00/0^^ The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 E-6 (3/81) i i ABSTRACT Underwater v o c a l i z a t i o n s were r e c o r d e d from pods of w i l d k i l l e r whales (O r e i n u s o r c a ) o f f Vancouver I s l a n d , B r i t i s h C olumbia, d u r i n g 1978-83. A c o u s t i c exchanges w i t h i n pods a r e dominated by r e p e t i t i o u s , p u l s e d c a l l s which can be o r g a n i z e d i n t o d i s c r e t e c a t e g o r i e s . Repeated e n c o u n t e r s w i t h 16 p h o t o g r a p h i c a l l y - i d e n t i f i e d ' r e s i d e n t ' pods demonstrate t h a t each pod produces a r e p e r t o i r e of 7 t o 17 (mean = 10.7) d i s c r e t e c a l l t y p e s . R e c o r d i n g s of c a p t i v e whales of known pod o r i g i n and h i s t o r i c a l f i e l d r e c o r d i n g s i n d i c a t e t h a t pod r e p e r t o i r e s remain s t a b l e f o r p e r i o d s of a t l e a s t 18 y e a r s (1965-83) and p o s s i b l y 25 y e a r s (1958-83). Each i n d i v i d u a l whale appears c a p a b l e of p r o d u c i n g most or a l l of the c a l l s i n i t ' s pod's r e p e r t o i r e . R e p e r t o i r e s a r e a p p a r e n t l y l e a r n e d . A l l d i s c r e t e c a l l t y p e s t e n d t o be used i n a l l ' a c t i v e ' c o n t e x t s , which c o n s i s t m a i n l y of f o r a g i n g and t r a v e l l i n g . Few c a l l t y pes a r e c l e a r l y c o r r e l a t e d w i t h s p e c i f i c b e h a v i o u r s . A c t i v i t i e s i n v o l v i n g t i g h t group f o r m a t i o n and p h y s i c a l i n t e r a c t i o n among pod members were accompanied by an i n c r e a s e i n the use of w h i s t l e s and v a r i a b l e p u l s e d sounds. S i g n i f i c a n t d i f f e r e n c e s e x i s t among the c a l l r e p e r t o i r e s of d i f f e r e n t pods. The 16 r e s i d e n t pods on the B.C. c o a s t can be ar r a n g e d i n t o 4 a c o u s t i c a s s o c i a t i o n s , each of which has a unique s e t of d i s c r e t e c a l l t y p e s . These a s s o c i a t i o n s a r e r e f e r r e d t o as ' c a l l t r a d i t i o n s ' , and the pods b e l o n g i n g t o a t r a d i t i o n form a ' c l a n ' . Pods w i t h i n each c l a n share some c a l l types, but may a l s o produce unique c a l l s . Shared c a l l s o f t e n have d i f f e r e n t p o d - s p e c i f i c r e n d i t i o n s . These d i f f e r e n c e s form a system of r e l a t e d d i a l e c t s w i t h i n each c a l l t r a d i t i o n . Three of the four r e s i d e n t c l a n s belong to a s i n g l e community, and pods from these c l a n s f r e q u e n t l y a s s o c i a t e with one another. Observed p a t t e r n s of a s s o c i a t i o n were o f t e n u n r e l a t e d t o a c o u s t i c r e l a t i o n s h i p s . The f o u r t h r e s i d e n t c l a n forms a community with a separate range. A community of 17 ' t r a n s i e n t ' pods i s sympatric with but s o c i a l l y i s o l a t e d from the r e s i d e n t communities. T h i s community has a wide range, and appears t o c o n s i s t of a s i n g l e c a l l t r a d i t i o n . The c a l l t r a d i t i o n s and d i a l e c t s d e s c r i b e d here are appar e n t l y unique among mammals. Various hypotheses to account for t h e i r o r i g i n and adaptive s i g n i f i c a n c e are di s c u s s e d . Clans c o u l d represent independent l i n e a g e s which a r r i v e d on the B.C. coast through a s e r i e s of u n r e l a t e d founding events. As the founding pod of each c l a n grew and d i v i d e d , i t s group-s p e c i f i c c a l l r e p e r t o i r e d i v e r g e d , e i t h e r through f u n c t i o n l e s s c u l t u r a l d r i f t or by an a c t i v e process promoting a c o u s t i c d i f f e r e n t i a t i o n of r e l a t e d groups. D i a l e c t s may have no s e l e c t i v e value, or they may serve as k i n - r e c o g n i t i o n s i g n a l s for m a i n t a i n i n g pod cohesion and i d e n t i t y or a v o i d i n g excessive i n b r e e d i n g . iv TABLE OF CONTENTS ABSTRACT i i LIST OF TABLES v i i i LIST OF FIGURES .x ACKNOWLEDGEMENTS xv GENERAL INTRODUCTION 1 Part I: BEHAVIOUR AND VOCALIZATIONS OF RESIDENT KILLER WHALES 5 Introduction 6 Materials and Methods 8 1. The Study Animals ...8 2. F i e l d Observations and Recordings 8 3. Behaviour C l a s s i f i c a t i o n 9 4. Sound Analysis 10 Results 12 1. Description and Definitions of Sound Types 12 A) Clic k s ..12 B) Whistles 13 C) Pulsed C a l l s 13 Pulsed C a l l C l a s s i f i c a t i o n : 14 •2. Description of Behavioural A c t i v i t i e s 17 A) Foraging «,.. . 1 7 B) Tr a v e l l i n g 23 C) Group-Resting 30 D) S o c i a l i z i n g 31 E) Beach Rubbing 32 3. Sounds Produced D u r i n g D i f f e r e n t A c t i v i t i e s 33 A) F o r a g i n g 33 B) T r a v e l l i n g . 37 C) G r o u p - R e s t i n g 38 D) S o c i a l i z i n g 39 E) Beach Rubbing 39 4. C o r r e l a t i o n of D i s c r e t e C a l l Types w i t h A c t i v i t y C o n t e x t 40 The C a l l R e p e r t o i r e of the A-pods: 41 C a l l R e p e r t o i r e s of I n d i v i d u a l Whales: 42 A) F o r a g i n g 43 B) T r a v e l l i n g 47 C) G r o u p - R e s t i n g 50 D) S o c i a l i z i n g 51 E) Beach Rubbing 51 F) Other C o n t e x t s 51 Large A g g r e g a t i o n s : 54 Pods M e e t i n g : 54 E x c i t e m e n t : 60 5. P a t t e r n s of D i s c r e t e C a l l O c c u r r e n c e 63 D i s c u s s i o n 73 P o t e n t i a l Communicative R o l e s of P u l s e d C a l l s and W h i s t l e s 73 I n f o r m a t i o n Content of D i s c r e t e C a l l Types 78 P a r t I I : DIALECTS AND CALL TRADITIONS IN RESIDENT KILLER WHALES 85 v i I n t r o d u c t i o n 86 M a t e r i a l s and Methods 89 1. The Study Animals 89 2. F i e l d O b s e r v a t i o n s And R e c o r d i n g s 95 3. Sound a n a l y s i s 96 D i s c r e t e C a l l C l a s s i f i c a t i o n : 97 P a t t e r n s of C a l l O c c u r r e n c e : 99 R e s u l t s 100 1. R e c o r d i n g and I d e n t i f i c a t i o n of C a l l R e p e r t o i r e s ....100 2. D i a l e c t s of N o r t h e r n Community R e s i d e n t Pods 101 A. A-Clan 102 I) C a l l c h a r a c t e r i s t i c s 102 I I ) C a l l use 129 I I I ) Summary of a c o u s t i c a s s o c i a t i o n s : A - c l a n ....147 B. G-Clan 155 I) C a l l c h a r a c t e r i s t i c s 155 I I ) C a l l use 165 I I I ) Summary of a c o u s t i c a s s o c i a t i o n s : G - c l a n ....168 C. R-Clan 171 I) C a l l c h a r a c t e r i s t i c s 171 I I ) C a l l use 174 I I I ) Summary of a c o u s t i c a s s o c i a t i o n s : R - c l a n ....177 3. D i a l e c t s of Southern Community R e s i d e n t Pods 180 A. J - C l a n 180 I) C a l l c h a r a c t e r i s t i c s 180 I I ) C a l l use 191 I I I ) Summary of a c o u s t i c a s s o c i a t i o n s : J - c l a n ....199 4. Comparison of D i a l e c t S i m i l a r i t y and Pod D i s t r i b u t i o n s 204 5. Comparison of D i a l e c t S i m i l a r i t y and Pod Assoc i a t i o n s 208 D i s c u s s i o n . . 215 O r i g i n s of V o c a l V a r i a t i o n 220 K i l l e r Whale D i a l e c t s : B y p r o d u c t s or A d a p t a t i o n s ? 228 V o c a l V a r i a t i o n and P o p u l a t i o n S t r u c t u r e 231 Time Depth of V o c a l D i f f e r e n t i a t i o n 233 P a r t I I I : VOCAL BEHAVIOUR AND DIALECTS IN TRANSIENT KILLER WHALES 236 I n t r o d u c t i o n 237 M a t e r i a l s and Methods 239 1. F i e l d O b s e r v a t i o n s and R e c o r d i n g 239 2. Sound A n a l y s i s 239 R e s u l t s 240 1. C h a r a c t e r i s t i c s of T r a n s i e n t Whales 240 2. A c o u s t i c Behaviour 243 3. D i a l e c t s 247 D i s c u s s i o n 257 GENERAL SUMMARY AND CONCLUSIONS 260 LITERATURE CITED 265 APPENDIX I : SUMMARY OF RESIDENT POD ENCOUNTERS 280 APPENDIX I I : SUMMARY OF HISTORICAL.FIELD RECORDINGS 286 APPENDIX I I I : DESCRIPTIVE STATISTICS AND ANOVA COMPARISONS OF CALL VARIABLES 288 v i i i L IST OF TABLES Ta b l e I . A-pod c a l l t y pes produced by c a p t i v e whales 44 T a b l e I I . Frequency of o c c u r r e n c e of d i s c r e t e c a l l t y p e s produced by pods A1 , A4 and A5 w h i l e f o r a g i n g 46 Tab l e I I I . D i f f e r e n c e s i n c a l l o c c u r r e n c e d u r i n g a c t i v i t y c a t e g o r i e s 52 Ta b l e IV. Comparison of c a l l N2 s t r u c t u r e d u r i n g normal v e r s u s e x c i t e d c o n t e x t s 58 Ta b l e V. Con t i n g e n c y t a b l e a n a l y s i s of t r a n s i t i o n s between common c a l l t y p e s of pods A1 , A4 and A5 65 Tab l e V I . T r a n s i t i o n m a t r i x of common A-pod c a l l s showing s i g n i f i c a n t d e p a r t u r e s from a random model 68 Tab l e V I I . I n d i c e s of a s s o c i a t i o n of common A-pod c a l l s based on t r a n s i t i o n f r e q u e n c i e s 69 Ta b l e V I I I . S i z e and c o m p o s i t i o n of r e s i d e n t pods i d e n t i f i e d o f f Vancouver I s l a n d . 94 Ta b l e IX. C a l l t ypes and sub t y p e s produced by pods of the A - c l a n i n the n o r t h e r n r e s i d e n t community 103 Tab l e X. Degree of s i m i l a r i t y i n d i a l e c t s of A - c l a n pods. .152 Ta b l e X I . C a l l t y p e s and subtypes produced by pods of the G-c l a n i n the n o r t h e r n r e s i d e n t community 156 Ta b l e X I I . C a l l t ypes and subtypes produced by pods of the J - c l a n i n the sou t h e r n r e s i d e n t community 181 Ta b l e X I I I . S o c i a l a s s o c i a t i o n s of n o r t h e r n r e s i d e n t community pods. 209 T a b l e XIV. S o c i a l a s s o c i a t i o n s of southern r e s i d e n t community pods 213 T a b l e XV. S i z e and c o m p o s i t i o n of t r a n s i e n t pods i d e n t i f i e d o f f Vancouver I s l a n d 241 T a b l e XVI. D i s c r e t e c a l l t y pes r e c o r d e d , from t r a n s i e n t pods 248 X LIST OF FIGURES F i g u r e 1. Spectrograms of t y p i c a l and a b e r r a n t v e r s i o n s of c a l l s N2 and N7 15 F i g u r e 2. Spectrograms of n o r t h e r n r e s i d e n t c a l l t y p e s N23, N25, and N32 r and i m i t a t i o n s of these c a l l s by the A-pods 18 F i g u r e 3. The d i s t r i b u t i o n of a c t i v i t i e s of n o r t h e r n -community r e s i d e n t k i l l e r whales 20 F i g u r e 4. D u r a t i o n s of a c t i v i t y bouts i n northern-community r e s i d e n t k i l l e r whales 24 F i g u r e 5. Speed of p r o g r e s s i o n of northern-community r e s i d e n t whales d u r i n g d i f f e r e n t a c t i v i t y s t a t e s 26 F i g u r e 6. D u r a t i o n s of d i v e s f o r northern-community r e s i d e n t whales i n d i f f e r e n t a c t i v i t y s t a t e s 28 F i g u r e 7. Frequency h i s t o g r a m of d i s c r e t e , v a r i a b l e and a b e r r a n t c a l l o c c u r r e n c e d u r i n g f o u r a c t i v i t y s t a t e s of pods A1 , A4 and A5. 35 F i g u r e 8. Frequency h i s t o g r a m s of d i s c r e t e c a l l types produced by pods A l , A4 and A5, d u r i n g d i f f e r e n t a c t i v i t y s t a t e s 48 F i g u r e 9. Examples of c a l l s N2 and N16 g i v e n i n t y p i c a l and e x c i t e d forms ..........56 F i g u r e 10. Spectrograms of " e x c i t e m e n t c a l l s " and c a l l type N1iv m o d i f i e d by h i g h a r o u s a l 61 F i g u r e 11. C l u s t e r diagram of a s s o c i a t i o n s among common x i c a l l types produced by pods A1 , A4 and A5 70 Figure 12. Map of the known d i s t r i b u t i o n s of the northern and southern communities of resident k i l l e r whale pods, and place names mentioned in the text ....92 Figure 13. Spectrograms of A-clan c a l l type N1 105 Figure 14. Spectrograms of A-clan c a l l types N3, N5 and N1 1 1 08 Figure 15. Spectrograms of A-clan c a l l types N7 and N8. ...112 Figure 16. Spectrograms and st r u c t u r a l measurements of A-clan c a l l type N12 116 Figure 17. Spectrograms of A-clan c a l l types N2, N4 and N9. 119 Figure 18. Spectrograms of A-clan c a l l types N10, N13, N17, N19, N27 and N47 123 Figure 19. Spectrograms of A-clan c a l l types N16, N18, N20 and N21 . 1 26 Figure 20. Frequency d i s t r i b u t i o n s of c a l l s produced by pods A1 , A4 and A5 while foraging together 131 Figure 21. Frequency d i s t r i b u t i o n s of c a l l s produced by pods A1 , A4 and A5, during 1978-83 combined 133 Figure 22. Frequency d i s t r i b u t i o n s of c a l l s produced by A1 pod alone, 1971-1983 135 Figure 23. Frequency d i s t r i b u t i o n s of c a l l s produced by B pod. .. 138 Figure 24. Cluster diagram of c a l l associations in the repertoire of B pod 141 Figure 25. Frequency d i s t r i b u t i o n s of c a l l s produced by pods H and 11 143 F i g u r e 26. Frequency d i s t r i b u t i o n s of c a l l s produced by C and D pods, and the c a p t i v e whale "Namu" 145 F i g u r e 27. C l u s t e r diagrams of c a l l a s s o c i a t i o n s i n the r e p e r t o i r e s of A ) , C pod, and B ) , the c a p t i v e whale "Namu" 1 48 F i g u r e 28. Spectrograms of s e l e c t e d C-pod c a l l t y p e s produced i n 1978-80 and by the c a p t i v e whale "Namu" i n 1 965 1 50 F i g u r e 29. C l u s t e r diagram of a c o u s t i c a s s o c i a t i o n s of A-c l a n pods 153 F i g u r e 30. Spectrograms of G-cl a n c a l l t y p e s N23 and N25. .158 F i g u r e 31. Spectrograms of G-cl a n c a l l t y p e s N24, N26, N28, N29, N30, N44 and N48 160 F i g u r e 32. Spectrograms of G-clan c a l l t y p e s N38, N39, N40, N41 , N45 and N46 163 F i g u r e 33. Frequency d i s t r i b u t i o n s of c a l l s produced by G-c l a n pods 166 F i g u r e 34. C l u s t e r diagrams of c a l l a s s o c i a t i o n s i n the r e p e r t o i r e s of pods G and 111 169 F i g u r e 35. Spectrograms of R - c l a n c a l l t y p e s N32, N33, N34, N35, N36, N42, N43, N49, N50 and N51 172 F i g u r e 36. Frequency d i s t r i b u t i o n s of R - c l a n c a l l s 175 F i g u r e 37. C l u s t e r diagram of c a l l a s s o c i a t i o n s i n the r e p e r t o i r e s of R and W pods combined 178 F i g u r e 38. Spectrograms of J - c l a n c a l l t y p e s S2, S8, S13 and S37 182 x i i i F i g u r e 39. Spectrograms of J - c l a n c a l l t y p e s S1, S4, S5, S6, S7, S10, S16, S17, and S42 185 F i g u r e 40. Spectrograms of c a l l t y pes S3, S9, S12, S14, S41, S44, g i v e n o n l y by J pod 187 F i g u r e 41. Spectrograms of c a l l t y p e s S18, S19, S22, S31, S33, S36, S40, g i v e n o n l y by L pod 189 F i g u r e 42. Frequency d i s t r i b u t i o n s of J pod c a l l s r e c o r d e d i n f o r a g i n g and t r a v e l l i n g c o n t e x t s , 1979-83 192 F i g u r e 43. C l u s t e r diagram of c a l l a s s o c i a t i o n s i n the r e p e r t o i r e of J pod ...194 F i g u r e 44. Frequency d i s t r i b u t i o n s of J-pod c a l l t y p e s r e c o r d e d d u r i n g 1958-61, and from the c a p t i v e whales "Moby D o l l " and "Shamu" 197 F i g u r e 45. Frequency d i s t r i b u t i o n s of c a l l s produced by L pod w h i l e f o r a g i n g and t r a v e l l i n g d u r i n g 1980-83, and from c a p t i v e whales i n 1973 200 F i g u r e 46. C l u s t e r diagram of c a l l a s s o c i a t i o n s i n the r e p e r t o i r e of L pod 202 F i g u r e 47. Frequency of o c c u r r e n c e of n o r t h e r n r e s i d e n t pods o f f n o r t h e a s t e r n Vancouver I s l a n d , 1978-83 205 F i g u r e 48. Summary of a c o u s t i c r e l a t i o n s h i p s of r e s i d e n t pods i n B r i t i s h Columbia 216 F i g u r e 49. Examples of c a l l t y p e s N1 and N8 g i v e n by H pod. 225 F i g u r e 50. Sample spectrograms of c a l l type T1 244 F i g u r e 51. Spectrograms of X-pod c a l l s T2, T3, T4, T5, and T6 250 x i v F i g u r e 52. Frequency d i s t r i b u t i o n of c a l l s produced by X pod 252 F i g u r e 53. Spectrograms of t r a n s i e n t pod c a l l s T7 and T8. .255 XV ACKNOWLEDGEMENTS I am indebted to many people who contributed in various ways towards the completion of thi s study. Foremost is Deborah Cavanagh Ford, who played an active role in a l l aspects of the work,, especially in the f i e l d , for which I am very grateful. The project would not have been possible without the involvement of Michael Bigg, who helped by encouraging the study in i t s planning stages, providing l o g i s t i c a l support, identifying individual whales from my photographs, and making several underwater recordings. I am very grateful to him for thi s generous assistance, and for numerous stimulating discussions which helped to develop many of the ideas in t h i s thesis. I also thank Graeme E l l i s for sharing his knowledge of k i l l e r whales, providing f i e l d assistance, and helping with photo-identifications, and Ian MacAskie for encouragement. The study was supervised by H. Dean Fisher, who I thank for his support throughout a l l phases of the work. For help with f i e l d l o g i s t i c s , I am grateful to Jim and Anne Borrowman, B i l l and Donna Mackay, Trev and Flo Anderson, Carl Prince, Allan and Darleen Tansky, Rob Waters, Gary Fletcher, and the numerous volunteer observers who phoned in whale sightings. Tapes of k i l l e r whale sounds were kindly made available by Eric h Hoyt, Paul Spong, Dan McSweeney, Dean Fisher, Michael Bigg, Graeme E l l i s , Richard Osborne, Mervin Black, xvi Marilyn Dahlheim, Charles Malme, David Bain, Jon Stern, William Watkins and Paul Thompson. Important components of the underwater recording systems were s k i l l f u l l y designed, assembled and maintained by John Mair. Advice on s t a t i s t i c a l analysis was provided by Peter Larkin, and assistance with computer programming was given by Dave Z i t t i n and Glenn Sutherland. Edie Bydemast and P h i l l i p a Nelson helped draft the thesis figures. Funds for this research were provided by the Federal Departments of Supply and Services and Fisheries and Oceans, and the National Science and Engineering Research Council through contracts and grants to H.D. Fisher. Additional funds were provided by grants from the Vancouver Public Aquarium Association. F i n a l l y , I thank my research committee members, H.D. Fisher, M. Bigg, James N.M. Smith, Don McPhail and Tony S i n c l a i r , for constructive comments on e a r l i e r drafts of the thesis. $SIGNOFF 1 GENERAL INTRODUCTION P r i o r t o the 1970's, our knowledge of the n a t u r a l h i s t o r y and b e h a v i o u r of c e t a c e a n s was based p r i m a r i l y on c a r c a s s a n a l y s i s from w h a l i n g o p e r a t i o n s and o b s e r v a t i o n s of c a p t i v e specimens. S t u d i e s of the underwater a c o u s t i c communication of c a p t i v e d o l p h i n s c o n s i s t e d p r e d o m i n a t e l y of attempts t o c a t a l o g u e t h e i r complex s i g n a l s and a s s e s s t h e i r p o t e n t i a l f o r i n f o r m a t i o n t r a n s f e r ( e . g . , Dreher and Evans 1964; Lang and Smith 1965; Dreher 1S66; B a s t i a n 1967). Few of thes e s t u d i e s s e r i o u s l y c o n s i d e r e d how the sounds might s e r v e the an i m a l s i n t h e i r n a t u r a l h a b i t a t . R e p o r t s of underwater v o c a l i z a t i o n s of f r e e - r a n g i n g c e t a c e a n s were based on s p o r a d i c , b r i e f e n c o u n t e r s and a l s o d e a l t m a i n l y w i t h p h y s i c a l d e s c r i p t i o n s and c l a s s i f i c a t i o n of the sounds ( e . g . , S c h e v i l l and Lawrence 1949; S c h e v i l l 1964; B u s n e l and D z e i d z i c 1966). F u n c t i o n a l i n t e r p r e t a t i o n s r e l i e d on a n e c d o t a l o b s e r v a t i o n s of b e h a v i o u r and s o c i a l o r g a n i z a t i o n , s i n c e l i t t l e s y s t e m a t i c f i e l d work had been c a r r i e d out ( e . g . , Dreher and Evans 1964; Evans and B a s t i a n 1967). In r e c e n t y e a r s , a t r e n d towards r e s e a r c h i n t o the l i f e h i s t o r y and s o c i a l b e h a v i o u r of w i l d c e t a c e a n s has de v e l o p e d . D e s p i t e the many d i f f i c u l t i e s a s s o c i a t e d w i t h s t u d y i n g t h e s e a n i m a l s a t s e a , a g r e a t d e a l has been d i s c o v e r e d . Most of thes e i n v e s t i g a t i o n s have made use of new methods f o r i d e n t i f y i n g i n d i v i d u a l whales and d o l p h i n s from n a t u r a l l y - o c c u r r i n g markings ( e . g . , B i g g e t a l . 1976; D a r l i n g 1977; Wursig and Wursig 1977; Wursig 1978; N o r r i s and D o h l , 1980a; Payne (ed.) 1983). These 2 and o t h e r new t e c h n i q u e s have a l s o been employed i n p i o n e e r i n g s t u d i e s of v o c a l communication i n m y s t i c e t e s , e s p e c i a l l y those c o n c e r n i n g the song of humpback whales (Megaptera n o v a e a n g l i a e ) (Payne (ed.) 1983; Tyack 1981) and the c a l l s of r i g h t whales (Eubalaena a u s t r a l i s ) ( C l a r k and C l a r k 1980; C l a r k 1982, 1983). S e v e r a l i n t e n s i v e , l o n g - t e r m s t u d i e s of the behaviour and s o c i a l o r g a n i z a t i o n of o d o n t o c e t e s have been conducted r e c e n t l y ( e . g . , Wursig and Wursig 1977, 1979, 1980; Saayman and T a y l e r 1979, N o r r i s and Dohl 1980a; W e l l s e t a l . 1980) but few of t h e s e have d e a l t w i t h underwater communication. One e x c e p t i o n i s a study of the a c o u s t i c b e h a v i o u r of Hawaiian s p i n n e r d o l p h i n s ( S t e n e l l a l o n q i r o s t r i s ) c a r r i e d out by Brownlee and N o r r i s (1983) i n c o n j u n c t i o n w i t h a broad i n v e s t i g a t i o n of the n a t u r a l h i s t o r y and b e h a v i o u r of the s p e c i e s ( N o r r i s and Dohl 1980a; W e l l s and Wursig 1983; Wursig and Wursig 1983; Wursig et a l . 1983). Other i m p o r t a n t work on odontocete communication i n c l u d e s Watkins and S c h e v i l l ' s (1977) study of the 'codas' of sperm whales ( P h y s e t e r catodon) u s i n g m u l t i - h y d r o p h o n e a r r a y s . In t h i s t h e s i s , I d e s c r i b e the r e s u l t s of a f i v e - y e a r f i e l d s tudy of the underwater v o c a l i z a t i o n s and b e h a v i o u r of k i l l e r whales ( O r e i n u s o r c a ) i n B r i t i s h Columbia c o a s t a l w a t e r s . When I began t h i s a c o u s t i c study i n 1978, much of t h e fundamental b i o l o g y of l o c a l k i l l e r whales had r e c e n t l y been d i s c o v e r e d ( B i g g et a l . 1976). K i l l e r whales were found t o l i v e i n s t a b l e s o c i a l g r o u p s , or 'pods', many of which c o u l d be encountered r e l i a b l y i n p r e d i c t a b l e l o c a t i o n s on the c o a s t a t c e r t a i n t imes of the y e a r . T h i s seemed t o be an i d e a l p o p u l a t i o n upon which 3 to base an in-depth examination of the role of vocalization in the s o c i a l behaviour of a free-ranging odontocete. My i n i t i a l objectives were rather broad, since no previous accounts of the sounds of wild k i l l e r whales were av a i l a b l e . I planned to encounter and record as many pods as possible in a variety of s o c i a l and behavioural contexts to examine possible correlations of vocalizations and a c t i v i t y . In addition, I hoped to compare the vocal patterns of d i f f e r e n t pods to test a hypothesis that acoustic communication may be important in maintaining the stable s o c i a l structure in the population. Early in the study, i t became apparent that marked differences existed in the vocalizations of certain pods. Following this discovery, I decided to place an emphasis on t h i s aspect of the whale's vocal behaviour to document in d e t a i l what appeared to be a unique phenomenon among mammals. This emphasis continued throughout the f i e l d research and i s maintained in t h i s thesis. The thesis i s divided into three independent sections. The f i r s t , Part I, examines the vocalizations of selected pods in r e l a t i o n to the s o c i a l and behavioural contexts in which they occur. The p r i n c i p a l aim of t h i s section is to describe the manner in which sounds are used within a t y p i c a l s o c i a l group, and to discuss their probable communicative functions. Part II describes the s i m i l a r i t i e s and differences in group-specific vocal repertoires within a population of 16 'resident' pods occupying the B.C. coast. The geographic d i s t r i b u t i o n and s o c i a l associations of these pods are compared to their vocal 4 t r a d i t i o n s and dialects in an attempt to explain the o r i g i n and adaptive significance of the acoustic variations. The f i n a l section, Part III, considers the vocal d i a l e c t s within a population of 'transient' k i l l e r whales which i s sympatric with but s o c i a l l y d i s t i n c t from resident pods. 5 PART I BEHAVIOUR AND VOCALIZATIONS OF RESIDENT KILLER WHALES 6 INTRODUCTION Our u n d e r s t a n d i n g of the f u n c t i o n of a c o u s t i c communication i n c e t a c e a n s i s poor. T h i s r e s u l t s i n p a r t from our l a c k of knowledge of the s o c i a l o r g a n i z a t i o n and b e h a v i o u r of whales and d o l p h i n s i n t h e i r n a t u r a l h a b i t a t s . U n t i l t h e s e a s p e c t s of the a n i m a l s ' b i o l o g y are w e l l u n d e r s t o o d , i t w i l l not be p o s s i b l e t o a r r i v e a t any r e a l i s t i c i n t e r p r e t a t i o n of t h e i r communication systems. Most p r e v i o u s s t u d i e s on the v o c a l i z a t i o n s of k i l l e r whales have been conducted on c a p t i v e a n i m a l s , h e l d e i t h e r a l o n e or i n groups of t h r e e or l e s s . They have d e a l t p r i m a r i l y w i t h p h y s i c a l d e s c r i p t i o n and c l a s s i f i c a t i o n of the s i g n a l s (Newman and McGeer 1966; S c h e v i l l and Watkins 1966; Spencer et a l . 1967; S i n g l e t o n and P o u l t e r 1967; P o u l t e r 1968; Dahlheim and Awbrey 1982). R e p o r t s of k i l l e r whale v o c a l i z a t i o n s i n the w i l d have r e l i e d on r e c o r d i n g s a c q u i r e d d u r i n g s h o r t e n c o u n t e r s w i t h u n i d e n t i f i e d groups and have a l s o d e a l t m a i n l y w i t h d e s c r i p t i o n s of s i g n a l s t r u c t u r e ( V a l dez 1961; S t e i n e r et a l . 1979; Awbrey et a l . 1982). In t h i s c h a p t e r , I d e s c r i b e the underwater v o c a l i z a t i o n s of r e s i d e n t k i l l e r whales i n the c o a s t a l w a t e r s of B r i t i s h C olumbia. I attempt t o i n t e r p r e t the communicative f u n c t i o n s of thes e sounds from the s o c i a l and b e h a v i o u r a l c o n t e x t s i n which they o c c u r . The r e c o r d i n g s and b e h a v i o u r a l o b s e r v a t i o n s r e p o r t e d here were c o l l e c t e d s y s t e m a t i c a l l y over a p e r i o d of f i v e y e a r s , from a p o p u l a t i o n of a p p r o x i m a t e l y 230 i n d i v i d u a l l y -i d e n t i f i e d r e s i d e n t k i l l e r whales ( B i g g 1982). The r e s u l t s show 7 that there are consistent correlations between the types of sounds used within s o c i a l groups, or pods, of k i l l e r whales, and the a c t i v i t i e s of the group. It is also apparent that much of the communicative function of k i l l e r whale c a l l s may be related to factors responsible for the development of group-specific repertoires, or d i a l e c t s , among pods (Part I I ) . 8 MATERIALS AND METHODS _1_. The Study Animals K i l l e r whales in B r i t i s h Columbia coastal waters l i v e in stable s o c i a l groups, or pods (Bigg et a l . 1976; Bigg 1982). The population is made up of 16 'resident' pods which can be seen r e l i a b l y in certain locations during the summer months, and 17 'transient' pods which are uncommon and irregular in appearance. Resident pods are divided into two communities which occupy separate ranges (Fig. 12, Part I I ) . Pods within each community frequently associate, but the two communities do not mix. Resident pods range in size from 4 to 50 individuals, with a mean of 13.4. Size and composition of each resident pod are l i s t e d in Table VIII (Part I I ) . Further d e t a i l s of the structure and dynamics of resident and transient pods are given in Parts II and II I . 2. F i e l d Observations and Recordings Resident k i l l e r whales were encountered on a t o t a l of 154 days during 1978-83 in various locations around Vancouver Island. Pods were located and i d e n t i f i e d from unique naturally-occurring markings in the manner described in Part I I . A l l 16 resident pods known to occur in B.C. waters were observed and recorded. Observations of the spacing pattern, movements, and other behaviours of whales throughout each encounter were noted either by hand or on a tape recorder. In most cases, concurrent behavioural observations were also recorded on a second track of 9 the underwater recording. Spacing patterns and movements of whales were logged on small-scale charts in the f i e l d . Positions of whales were determined by reference to nearby landmarks and used later to calculate speed of t r a v e l . Underwater acoustic recordings were made with several recording systems described in d e t a i l in Part II. Depending on ambient noise lev e l s and l o c a l sound-propagation c h a r a c t e r i s t i c s , useful recordings could be obtained at ranges up to 2 km from the animals. 3. Behaviour C l a s s i f i c a t i o n Most of the behaviours of resident pods can be grouped into five categories: foraging, t r a v e l l i n g , group-resting, s o c i a l i z i n g and beach rubbing. Generally there was a degree of synchrony of a c t i v i t i e s within a pod. However, individuals or subgroups in a pod occasionally engaged in a d i f f e r e n t a c t i v i t y than the rest of the group. In these cases, I considered the a c t i v i t y state of a pod to be the behaviour displayed by most of i t s members. A sample of 416 h of observations co l l e c t e d on 93 days spent with northern community pods was used to determine the durations of a c t i v i t y bouts and the rate of travel during d i f f e r e n t a c t i v i t i e s for resident whales. Bout durations were measured from the start of the encounter or the onset of the a c t i v i t y , u n t i l a change to a d i f f e r e n t a c t i v i t y occurred or u n t i l the encounter ended. Occasionally, more than one a c t i v i t y bout was recorded simultaneously when two or more pods t r a v e l l i n g in the same v i c i n i t y were engaged in d i f f e r e n t 10 a c t i v i t i e s . 4. Sound A n a l y s i s Most k i l l e r whale s o c i a l s i g n a l s , or c a l l s , can be c l a s s i f i e d by ear i n t o d i s c r e t e c a t e g o r i e s based on d i s t i n c t i v e s t r u c t u r a l c h a r a c t e r i s t i c s . F o l l o w i n g p r e l i m i n a r y a u r a l c l a s s i f i c a t i o n , samples of c a l l t y p e s were a n a l y z e d u s i n g a Kay 7029A spectrum a n a l y z e r . Most spectrograms were made u s i n g an 80-8000 Hz frequency range w i t h a narrow 45 Hz f i l t e r bandwidth. For a more d e t a i l e d d e s c r i p t i o n of c a l l c l a s s i f i c a t i o n methodology, see P a r t I I . To examine the p a t t e r n s of c a l l o c c u r r e n c e and c o r r e l a t i o n s w i t h b e h a v i o u r , c o n t i n u o u s s e c t i o n s of t a p es were d i v i d e d i n t o 10-min time p e r i o d s , each l a b e l l e d as t o the pod or pods p r e s e n t a t the time and the p r e v a i l i n g a c t i v i t y s t a t e . P r o p o r t i o n s f o r each c a l l type i n each time p e r i o d were c a l c u l a t e d . These were t r a n s f o r m e d u s i n g the a r c s i n e square r o o t , and used as r e p l i c a t e s i n an a n a l y s i s of v a r i a n c e (ANOVA) w i t h B a r l e t t ' s t e s t of v a r i a n c e homogeneity and S c h e f f e ' s t e s t f o r d e t e r m i n i n g the s i g n i f i c a n c e of d i f f e r e n c e s among means. T h i s t e c h n i q u e was chosen over a n a l y s i s of f r e q u e n c i e s s i n c e i t more a c c u r a t e l y r e f l e c t s the v a r i a b i l i t y i n the d a t a . A s s o c i a t i o n s of d i f f e r e n t c a l l t y p e s were examined by c a l c u l a t i n g the p r e c e d i n g and f o l l o w i n g t r a n s i t i o n f r e q u e n c i e s f o r c a l l s w i t h i n each min of the 10-min time p e r i o d s . These f r e q u e n c i e s were a r r a n g e d i n a m a t r i x , and compared t o a random model of e x p e c t e d f r e q u e n c i e s . Each t r a n s i t i o n p a i r was 11 examined for departure from the random model by condensing the matrix into a 2x2 contingency table about the t r a n s i t i o n of interest, then testing t h i s using the G - s t a t i s t i c (Sokal and Rohlf 1981). As pointed out by Slater (1973, 1983), i t is often of interest in such analyses to remove 'self t r a n s i t i o n s ' , or transitions between repetitions of the same c a l l , before condensing the matrix. This eliminates the strong influence of these t r a n s i t i o n s on other interactions within the matrix, and provides a better representation of the relationship of dif f e r e n t c a l l types. For this analysis, expected values for each t r a n s i t i o n pair and the degrees of freedom for a goodness-o f - f i t test were calculated by the method described in Lemon and Chatfield (1971, pp. 14-16). Following t h i s analysis, the preceding/following frequencies for each c a l l combination were summed and used to calculate an index of association. This index is a modified form of Dice's c o e f f i c i e n t of association (Morgan et a l . 1976) and normalizes the data to account for differences in the abundance of c a l l types: Index of Association = 2(transitions i > j + j > i) (tran s i t i o n s involving i) + (transitions involving j ) A cluster diagram was then created using these values to display the hierarchy of associations within the c a l l repertoire. 1 2 RESULTS J_. D e s c r i p t i o n and D e f i n i t i o n s of Sound Types The underwater sounds of k i l l e r whales f a l l i n t o t h r e e d i f f e r e n t c l a s s e s : A) C l i c k s C l i c k s a r e b r i e f p u l s e s of sound, t y p i c a l l y g i v e n i n s e r i e s , which a re g e n e r a l l y employed as e c h o l o c a t i o n s i g n a l s i n od o n t o c e t e s (see r e v i e w s by N o r r i s 1969; Popper 1980, Wood and Evans 1980, Watkins 1980). K i l l e r whale c l i c k s have been d e s c r i b e d from f i e l d r e c o r d i n g s by S t e i n e r e t a l . (1979) and Awbrey e t a l . (1982), and from o b s e r v a t i o n s of c a p t i v e a n i m a l s by S c h e v i l l and Watkins (1966) and D i e r c k s et a l . (1971 and 1973). These s t u d i e s demonstrate t h a t k i l l e r whale c l i c k s a r e q u i t e v a r i a b l e i n s t r u c t u r e . D u r a t i o n s of c l i c k s range from 0.5 t o 25 ms, and c l i c k r e p e t i t i o n r a t e s from a few t o over 300/s. Frequency c o n t e n t can be r e l a t i v e l y narrow t o broadband, w i t h emphases r a n g i n g as h i g h as 30 kHz. Some c l i c k s a r e composed of p a i r s of p u l s e s , or d o u b l e t s , w i t h i n t e r p u l s e i n t e r v a l s of 1.3 to 2 ms (Awbrey e t a l . 1982). C l i c k s were not a n a l y z e d e x t e n s i v e l y i n t h i s s t u d y . They were commonly heard i n most c o n t e x t s , u s u a l l y at r e p e t i t i o n r a t e s of 2 t o 50/s. F l u c t u a t i o n s i n r e p e t i t i o n r a t e over the d u r a t i o n of c l i c k s e r i e s resembled those produced by a c t i v e l y e c h o l o c a t i n g k i l l e r whales ( S c h e v i l l and Watkins 1966) and o t h e r o d o n t o c e t e s ( N o r r i s 1969, Watkins 1980). 1 3 B) W h i s t l e s W h i s t l e s a re c h a r a c t e r i z e d by a non-pulsed or c o n t i n u o u s waveform, which appears on a s p e c t r o g r a p h as a s i n g l e narrowband tone w i t h l i t t l e or no harmonic or sideband s t r u c t u r e (see example i n F i g . 2, Fo r d and F i s h e r 1983). K i l l e r whale w h i s t l e s have been r e p o r t e d by S t e i n e r et a l . (1979), Dahlheim and Awbrey (1982), Awbrey e t a l . (1982) and H o e l z e l and Osborne ( i n p r e s s ) . In the p r e s e n t s t u d y , w h i s t l e s o c c u r r e d a t f r e q u e n c i e s of 1.5 t o 18 kHz, a l t h o u g h most were between 6 and 12 kHz. W h i s t l e d u r a t i o n s ranged from 50 ms t o 10-12 s, and most c o n t a i n e d a number of m o d u l a t i o n s or abrupt s h i f t s i n fr e q u e n c y . A g r e a t v a r i e t y of w h i s t l e forms were r e c o r d e d , but no attempt was made to determine s t r u c t u r a l c a t e g o r i e s . C) P u l s e d C a l l s P u l s e d sounds a r e the most abundant and c h a r a c t e r i s t i c v o c a l i z a t i o n s produced by k i l l e r whales. These s i g n a l s have d i s t i n c t t o n a l p r o p e r t i e s because of h i g h p u l s e r e p e t i t i o n r a t e s . P u l s e d sounds u s u a l l y c o n t a i n abrupt and p a t t e r n e d s h i f t s i n p u l s i n g r a t e , r e s u l t i n g i n a wide v a r i e t y of unique-sounding c a l l s . The p u l s e s making up these c a l l s can have e i t h e r wide or r e s t r i c t e d bandwidths and r e p e t i t i o n r a t e s e x t e n d i n g t o 4000/s or more. The fundamental frequency s t r u c t u r e and r e p e t i t i o n r a t e s of p u l s e s can be v a r i e d i n d e p e n d e n t l y i n the same c a l l . Some s i g n a l s a re composed of two d i f f e r e n t p u l s i n g f r e q u e n c i e s , l i k e l y caused by resonance i n 14 the sound g e n e r a t i n g s t r u c t u r e . Many a l s o c o n t a i n an o v e r l a p p i n g narrowband t o n a l (or w h i s t l e ) component. Examples of these v a r i a t i o n s can be seen i n P a r t I I . In s p e c t r o g r a p h i c a n a l y s i s , p u l s e s g e n e r a t e d a t r e p e t i t i o n f r e q u e n c i e s s u r p a s s i n g t h a t of the a n a l y z e r f i l t e r bandwidth are r e s o l v e d as harmonics or s i d e b a n d s at i n t e r v a l s e q u i v a l e n t t o the r e p e t i t i o n f r e q u e n c y (see W a t kins 1967 f o r more d e t a i l s ) . . Most p u l s e d c a l l s r e c o r d e d i n t h i s study had r e p e t i t i o n f r e q u e n c i e s of 250 t o 2000 Hz. P r i m a r y energy was u s u a l l y between 1 and 6 kHz, w i t h h i g h f r e q u e n c y components e x t e n d i n g t o > 30 kHz. C a l l d u r a t i o n s ranged from l e s s than 50 ms t o > 10 ,s; the m a j o r i t y were between 0.5 and 1.5 s l o n g . P u l s e d C a l l C l a s s i f i c a t i o n : The m a j o r i t y of k i l l e r whale p u l s e d s i g n a l s f a l l i n t o d i s c r e t e s t r u c t u r a l c a t e g o r i e s . These c a l l t y p e s can n e a r l y always be d i s t i n g u i s h e d by e a r . V a r i a b i l i t y i n s t r u c t u r e o c c u r s w i t h i n a l l d i s c r e t e c a l l c a t e g o r i e s . C e r t a i n c a t e g o r i e s t e n d t o be more v a r i a b l e than o t h e r s . D i f f e r e n t c a l l t y p e s a r e so d i s t i n c t , however, t h a t most c a l l s can be a s s i g n e d t o d i s t i n c t c a t e g o r i e s w i t h o u t a m b i g u i t y . O c c a s i o n a l l y , h i g h l y i r r e g u l a r v e r s i o n s of d i s c r e t e c a l l t y p e s can be h e a r d . These " a b e r r a n t c a l l s " a r e c l e a r l y based on a g i v e n d i s c r e t e c a l l f o r m a t , but a r e g r e a t l y m o d i f i e d ( F i g . 1). On r a r e o c c a s i o n s , pods were obser v e d t o produce i m i t a t i o n s of c a l l t y p e s t h a t were not p a r t of t h e i r r e p e r t o i r e . S e v e r a l examples of t h e s e are shown i n F i g u r e 2. I m i t a t i o n s always i n v o l v e d c a l l s b e l o n g i n g t o o t h e r 15 Figure 1. Spectrograms of t y p i c a l and aberrant versions of c a l l s N2 and N7. See Part II for explanation of c a l l numbering scheme. 17 pods in the same community. Discrete pulsed c a l l s predominate in acoustic exchanges within pods. Some pulsed signals, however, are highly variable and cannot be c l a s s i f i e d into clearly-defined categories. This "variable c a l l " category includes complex, intergrading signals ranging from short squeaks and t r i l l s to long, raucous squawks. The variable c a l l category probably contains some highly aberrant renditions of discrete c a l l types. A t o t a l of 78 discrete c a l l types and 42 subtypes were i d e n t i f i e d in this study. Resident pods have repertoires of 7 to 17 di f f e r e n t c a l l types (mean = 10.7), while transient pods appear to have smaller repertoires of 2 to 6 c a l l s (see Part I I I ) . A complete c l a s s i f i c a t i o n of c a l l types and a description of pod repertoires i s given in Parts II and I I I . 2. Description of Behavioural A c t i v i t i e s Most a c t i v i t i e s of k i l l e r whales were grouped into fiv e major categories. Rate of tra v e l and duration of a c t i v i t y bouts were determined from a 416 h subsample of observation of resident pods in the northern community. With the exception of beach rubbing, described below, southern resident whales behave s i m i l a r l y . A) Foraging Foraging i s the most common group a c t i v i t y of resident pods. This behaviour accounted for 66.51% of the t o t a l observation period (Fig. 3). The category includes a l l 18 F i g u r e 2. Spectrograms of n o r t h e r n r e s i d e n t c a l l t y p e s N23, N25, and N32, and i m i t a t i o n s of t h e s e c a l l s by the A-pods. 19 r o T 1 500 ms 20 Figure 3. The d i s t r i b u t i o n of a c t i v i t i e s of northern-community resident k i l l e r whales. Values based on 416 h of observation c o l l e c t e d on 93 days. LU 2 8O-1 60-O 40 n=416 h DC O CL O rx 20-0-Foraging Travelling Resting Socializing Beach Rubbing ACTIVITY 22 o c c a s i o n s where the whales were known or s u s p e c t e d t o be f e e d i n g a c t i v e l y or s e a r c h i n g f o r p r e y . Whales were sometimes seen c a r r y i n g f i s h , e i t h e r whole or i n p a r t s , i n t h e i r mouths f o l l o w i n g a k i l l . S i t e s of presumed k i l l s were i n s p e c t e d whenever p o s s i b l e , and o f t e n s c a l e s and o t h e r s c r a p s c o u l d be c o l l e c t e d . Prey s p e c i e s taken were p r i m a r i l y P a c i f i c salmon (Oncorynchus s p p . ) , but r o c k f i s h (Sebastes spp.) and h e r r i n g (Clupea harenqus) were a l s o noted. Other i n d i c a t i o n s of f e e d i n g i n c l u d e d sudden lunges and changes i n d i r e c t i o n by i n d i v i d u a l s , h i g h - s p e e d swimming j u s t under the s u r f a c e , and m i l l i n g i n t i d e r i p s and o t h e r good f e e d i n g a r e a s . K i l l s were most o f t e n made by s i n g l e a n i m a l s , but o c c a s i o n l y subgroups of 2-4 whales were seen t o c o r r a l l and c a t c h f i s h c l o s e t o s h o r e . A p p a r e n t l y o r g a n i z e d e n c i r c l e m e n t and c a p t u r e of prey i n open water as d e s c r i b e d f o r k i l l e r whales f e e d i n g on h e r r i n g ( S t e i n e r e t a l . 1979; C h r i s t e n s e n 1978, 1982), p i n n i p e d s and c e t a c e a n s ( Z e n k o v i t c h 1938; Brown and N o r r i s 1956; N o r r i s and P r e s c o t t 1961; N o r r i s and Dohl 1980b) was not observed d u r i n g t h i s s t u d y . A l t h o u g h the d e t a i l s of group s p a c i n g and movements d u r i n g f o r a g i n g v a r i e d , a g e n e r a l p a t t e r n was e v i d e n t . Pod's t y p i c a l l y s e p a r a t e i n t o s m a l l e r subgroups t h a t d i s p e r s e w i d e l y over a r e a s of s e v e r a l square km. Subgroups a r e u s u a l l y composed of cows and t h e i r o f f s p r i n g . A l t h o u g h a l l members of the pod t r a v e l on a s i m i l a r c o u r s e , subgroups d i v e a t d i f f e r e n t t i m e s , and may i n d e p e n d e n t l y change d i r e c t i o n and m i l l f o r s h o r t p e r i o d s . Two or more pods commonly f o r a g e i n a s s o c i a t i o n . Of the 130 days t h a t n o r t h e r n r e s i d e n t whales were ob s e r v e d , pods were 23 a l o n e on o n l y 39 o c c a s i o n s ( 3 0 % ) . The average number of pods p r e s e n t i n the n o r t h e r n community per encounter was 2.81 (range = 1-10, sd = 1.79). When f o r a g i n g i n the same v i c i n i t y , members of d i f f e r e n t pods may e i t h e r mix or remain s e p a r a t e . Movements of the pods a r e u s u a l l y c l o s e l y c o o r d i n a t e d . F o r a g i n g bouts averaged 2.59 h i n d u r a t i o n (range = 0.45-7.4, sd = 1.50) ( F i g . 4 ) . Rates of group p r o g r e s s i o n v a r i e d from 3.1 t o 10.2 km/h, w i t h a mean of 6.0 km/h (sd = 1.48, n = 107 b o u t s ; F i g . 5 ) . D i v e t i m e s d u r i n g f o r a g i n g tend t o be s h o r t , a v e r a g i n g 0.34 min (sd = 0.20, n = 89; F i g . 6 ) . W h i l e swimming, i n d i v i d u a l s w i l l sometimes make 2 or 3 s h o r t , s h a l l o w d i v e s f o l l o w e d by a l o n g e r , 1-2 min d i v e . Other b e h a v i o u r s noted d u r i n g f o r a g i n g i n c l u d e o c c a s i o n a l b r e a c h e s , t a i l and f l i p p e r s l a p p i n g , spyhops ( v e r t i c a l r a i s i n g of the head above the s u r f a c e ) , and p l a y or ' s o c i a l i z i n g ' a c t i v i t i e s i n subgroups. B) T r a v e l l i n g A pod was c o n s i d e r e d t o be t r a v e l l i n g when a l l i t s members were moving on the same c o u r s e and a t the same speed, and t h e r e was no e v i d e n c e of f e e d i n g . T r a v e l l i n g whales te n d t o be l e s s d i s p e r s e d than w h i l e f o r a g i n g . O f t e n pod members l i n e up a b r e a s t i n a s i n g l e c o h e s i v e group and d i v e s y n c h r o n o u s l y f o r s h o r t p e r i o d s (mean = 0.49 min, sd = 0.38, n = 19; F i g . 6 ) . At o t h e r t i m e s , t i g h t l y -k n i t subgroups d i v e and s u r f a c e i n d e p e n d e n t l y w h i l e t r a v e l l i n g i n a l i n e , o f t e n p a r a l l e l t o the s h o r e . A e r i a l b e h a v i o u r i s g e n e r a l l y r e s t r i c t e d t o p o r p o i s i n g d u r i n g b u r s t s of h i g h - s p e e d 24 F i g u r e 4. D u r a t i o n s of a c t i v i t y bouts i n northern-community r e s i d e n t k i l l e r whales. Bars r e p r e s e n t means, l i n e s above and below b a r s e n c l o s e 95% c o n f i d e n c e i n t e r v a l s . T o t a l sample = 208 a c t i v i t y b o u t s . 25 CO cc o X 3-, 21 H 0 Foraging Travelling Resting Socializing Beach Rubbing n= 107 19 26 26 30 bouts ACTIVITY 26 Figure 5. Speed of progression of northern-community resident whales during di f f e r e n t a c t i v i t y states. Bars represent means, lines above and below bars enclose 95% confidence i n t e r v a l s . Sample sizes as in Figure 4. Foraging Travelling Resting Socializing ACTIVITY 28 Figure 6. Durations of dives for northern-community resident whales in d i f f e r e n t a c t i v i t y states. Bars represent means, li n e s above and below bars enclose 95% confidence i n t e r v a l s . 4-| < CL Q 2 -LU > Q £ 1-29 Foraging Travelling Resting Socializing n= 89 37 43 28 dives ACTIVITY 30 swimming. T r a v e l l i n g was the l e a s t common a c t i v i t y of n o r t h e r n r e s i d e n t pods, r e p r e s e n t i n g o n l y 4.19% of the observed time ( F i g . 3 ) . Bouts of t r a v e l l i n g were t y p i c a l l y b r i e f , a v e r a g i n g 0.92 h (range = 0.25-2.0, sd = 0.61, n = 19; F i g . 4 ) . D i s t a n c e s of 2.0 t o 6.7 km were c o v e r e d (mean = 8.6, sd = 4.71) a t speeds a v e r a g i n g 10.4 km/h (range = 6.5-20.4, sd = 3.7), s i g n i f i c a n t l y f a s t e r than f o r a g i n g (p < 0.001, S c h e f f e ' s t e s t ; F i g . 5 ) . C) G r o u p - R e s t i n g K i l l e r whales r e s t e i t h e r i n groups or i n d i v i d u a l l y . G r o u p - r e s t i n g a c c o u n t e d f o r 13.2% of the 416 h o b s e r v a t i o n p e r i o d . When g r o u p - r e s t i n g , a l l members of a pod j o i n t o g e t h e r i n a t i g h t l y - k n i t group, u s u a l l y w i t h a n i m a l s l i n e d up a b r e a s t . D i v e s and s u r f a c i n g s become h i g h l y r e g u l a r and c o o r d i n a t e d i n the group. Long d i v e s (mean = 3.07 min, range = 1.73-4.95, sd = 0.713, n = 43; F i g . 6) a r e i n t e r s p e r s e d w i t h s h o r t e r p e r i o d s a t the s u r f a c e (mean = 1.72 min, range = 1.07-2.97, sd = 0.41, n = 35). D u r i n g each s u r f a c e p e r i o d t h e whales make between 2 and 5 r e s p i r a t i o n s and s h a l l o w d i v e s . A l t h o u g h the e n t i r e pod i s g e n e r a l l y underwater or a t the s u r f a c e t o g e t h e r , members of m a t e r n a l subgroups m a i n t a i n c l o s e p h y s i c a l a s s o c i a t i o n and tend t o c o o r d i n a t e t h e i r movements. Bouts of g r o u p - r e s t i n g i n pods l a s t e d from 0.5 t o 7.5 h (mean = 2.1, n = 2 6 ) . P r o g r e s s i o n tends t o be v e r y slow ( F i g . 5 ) . T y p i c a l l y , the whales t r a v e l l e s s than 150 m d u r i n g each l o n g d i v e . O v e r a l l r a t e of t r a v e l d u r i n g r e s t i n g was 2.96 31 km/h (range = 0.93-6.4, sd = 1.41). On o c c a s i o n , pods break t h e i r d i v i n g p a t t e r n and remain a t the s u r f a c e f o r as l o n g as 15 min, s l o w l y m i l l i n g about. D) S o c i a l i z i n q S o c i a l i z i n g whales group t o g e t h e r and engage i n a v a r i e t y of p h y s i c a l i n t e r a c t i o n s and a e r i a l a c t i v i t i e s . A n i m a l s chase each o t h e r , r o l l and t h r a s h a t the s u r f a c e , and o c c a s i o n a l l y swim u p s i d e down. S e x u a l i n t e r a c t i o n s are common, and e r e c t i o n s are o f t e n v i s i b l e among both s u b a d u l t and a d u l t males. A e r i a l b e h a v i o u r s a r e f r e q u e n t , and may i n c l u d e b r e a c h e s , spyhops, b e l l y f l o p s , t a i l s l a p s , f l i p p e r s l a p s , d o r s a l - f i n s l a p s , and d i v e r s e forms of a c r o b a t i c l e a p s . I n d i v i d u a l s may a l s o p l a y w i t h i n a n i m a t e o b j e c t s such as f l o a t i n g k e l p , and s u r f i n the wake of p a s s i n g v e s s e l s . Most of t h e s e a c t i v i t i e s a r e e s p e c i a l l y p r e v a l e n t and v i g o r o u s among younger whales. A d u l t s o f t e n m i l l s l o w l y or r e s t i n d i v i d u a l l y i n the v i c i n i t y of f r o l i c k i n g j u v e n i l e s . When r e s t i n g , i n d i v i d u a l s s t o p swimming and l i e q u i e t l y a t the s u r f a c e , u s u a l l y f o r b r i e f p e r i o d s of < 2-3 min. D u r i n g t h i s time they b r e a t h e s l o w l y and g r a d u a l l y s i n k . Once i t s b l o w h o l e passes beneath the s u r f a c e , a r e s t i n g whale w i l l s t a r t moving once a g a i n . Bouts of s o c i a l i z i n g l a s t e d an average of 1.86 h (range 0.25-5.25, sd = 1.23, n = 2 6 ) , and a ccounted f o r 11.65% of the o v e r a l l b e h a v i o u r o b s e r v a t i o n s ( F i g . 3 ) . Many a s p e c t s of the group's s p a c i n g and movements ar e s i m i l a r t o g r o u p - r e s t i n g . 32 S o c i a l i z i n g whales u s u a l l y c o a l e s c e i n t o a s i n g l e group and d i v e t o g e t h e r f o r r e l a t i v e l y l o n g p e r i o d s (mean = 2.45 min, sd 0.52, n = 28; F i g . 6 ) . Group p r o g r e s s i o n i s u s u a l l y slow, (mean = 3.80 km/h, sd = 1.5, n = 26 b o u t s ) , but o c c a s i o n a l l y speeds of 10-15 km/h a r e a t t a i n e d i n h i g h l y a c t i v e pods. S o c i a l i z i n g o c c u r s p e r i o d i c a l l y i n subgroups of pods engaged i n f o r a g i n g , t r a v e l l i n g , or beach r u b b i n g b e h a v i o u r . E) Beach Rubbing Beach r u b b i n g was observed r e g u l a r l y among pods of the n o r t h e r n r e s i d e n t community, r e p r e s e n t i n g 4.5% of the group a c t i v i t i e s . T h i s b e h a v i o u r was seen p r i m a r i l y i n -the Johnstone S t r a i t a r e a ( F i g . 12, P a r t I I ) , where pods f r e q u e n t l y i n t e r r u p t f o r a g i n g s e s s i o n s w i t h v i s i t s t o a s p e c i f i c 0.5 km s e c t i o n of s h o r e l i n e on Vancouver I s l a n d i n o r d e r t o rub. T h i s a r e a i s c o m p r i sed of two s m a l l beaches and an underwater s h e l f some 3-6 m deep. The beaches and the s h e l f a r e c o v e r e d i n s m a l l (1-5 cm) smooth p e b b l e s , which are r e l a t i v e l y uncommon i n the r e g i o n . Rubbing was o b s e r v e d o c c a s i o n a l l y a t o t h e r g r a v e l beaches (see a l s o Thomas 1970), but o n l y s p o r a d i c a l l y . A n i mals rub by d i v i n g t o the bottom and r o l l i n g t h e i r l a t e r a l , d o r s a l and v e n t r a l s u r f a c e s a g a i n s t the pebble s h e l v e s f o r a p p r o x i m a t e l y 0.25-1.5 min b e f o r e s u r f a c i n g a g a i n . Large b u r s t s of a i r a r e o f t e n r e l e a s e d d u r i n g d i v e s , p r o b a b l y t o reduce buoyancy. Rubbing may be accompanied by i n d i v i d u a l r e s t i n g and s o c i a l i z i n g among nearby a n i m a l s . P e r i o d s of r u b b i n g v a r i e d from s e v e r a l minutes t o as l o n g as 1.5 h (mean = 33 0.62 h, sd = 0.4, n = 30 b o u t s , F i g . 4 ) . Beach r u b b i n g i s common among northern-community r e s i d e n t pods, e s p e c i a l l y f o r pods A1, A4, and A5. However, r e s i d e n t whales i n the sou t h e r n community have never been observed beach r u b b i n g , d e s p i t e many hours of i n t e n s i v e o b s e r v a t i o n (R. Osborne, M o c l i p s C e t o l o g i c a l S o c i e t y , p e r s . comm.; M. Bigg., p e r s . comm.; t h i s s t u d y ) . 3_. Sounds Produced D u r i n g D i f f e r e n t A c t i v i t i e s The f o l l o w i n g s e c t i o n d e s c r i b e s the p a t t e r n s of o c c u r r e n c e of the major sound c a t e g o r i e s ( i n t r o d u c e d above) among r e s i d e n t k i l l e r whales engaged i n the a c t i v i t i e s o u t l i n e d above. The c o n t e x t and use of s p e c i f i c d i s c r e t e c a l l t y p e s i s d i s c u s s e d i n S e c t i o n 4. A) F o r a g i n g Sounds produced by f o r a g i n g k i l l e r whales i n c l u d e e c h o l o c a t i o n - t y p e c l i c k s , w h i s t l e s , and both d i s c r e t e and v a r i a b l e p u l s e d c a l l s . ' E c h o l o c a t i o n ' c l i c k s a r e produced commonly d u r i n g f o r a g i n g a c t i v i t y , presumably t o l o c a t e and c a t c h f o o d . N o r m a l l y , s e v e r a l s i m u l t a n e o u s c l i c k s e r i e s , each a t d i f f e r e n t r e p e t i t i o n r a t e s , can be heard as a pod approaches. C l i c k r e p e t i t i o n r a t e s a r e g e n e r a l l y l e s s than 25/s, but o c c a s i o n a l l y go h i g h e r , a p p a r e n t l y when whales a r e s c a n n i n g o b j e c t s a c o u s t i c a l l y a t c l o s e range ( N o r r i s e t a l . 1967). I n t e n s e c l i c k b u r s t s 34 r e a c h i n g r e p e t i t i o n r a t e s of 200-300/s were o f t e n r e c o r d e d when a n i m a l s approached t o w i t h i n a few m of the hydrophone. S o c i a l s i g n a l s produced by f o r a g i n g k i l l e r whales a r e dominated by d i s c r e t e p u l s e d c a l l s . In r e c o r d i n g s of n o r t h e r n r e s i d e n t pods A1, A4, and A5 w h i l e f o r a g i n g , t h i s sound c a t e g o r y a c c o u n t e d f o r 95.2% of c a l l s produced ( F i g . 7 ) . Of t h e r e m a i n i n g s i g n a l s , 4.3% were v a r i a b l e p u l s e d c a l l s and 0.5% were a b e r r a n t r e n d i t i o n s of d i s c r e t e c a l l t y p e s . W h i s t l e s a r e g i v e n i n f r e q u e n t l y by f o r a g i n g k i l l e r whales. However, they a r e he a r d , a l o n g w i t h v a r i a b l e and a b e r r a n t c a l l s , when s o c i a l i z i n g o c c u r s w i t h i n subgroups of f o r a g i n g pods. The r a t e of c a l l i n g i s h i g h l y i r r e g u l a r d u r i n g f o r a g i n g . C a l l s may be produced r a p i d l y a t r a t e of 25-50/min, or s p o r a d i c a l l y a t r a t e s of < 5/min. P e r i o d s w i t h o u t c a l l i n g may p r e v a i l f o r a few min t o > 1 h. I t i s o f t e n v e r y d i f f i c u l t t o p r e d i c t from the s u r f a c e b e h a v i o u r of f o r a g i n g a n i m a l s when they w i l l be c a l l i n g and, i f so, a t what r a t e . Whales f o r a g i n g q u i e t l y may a b r u p t l y b e g i n c a l l i n g f o r s e v e r a l minutes then s u b s i d e i n t o s i l e n c e once a g a i n , a l l w i t h o u t any o b v i o u s change i n b e h a v i o u r . The r a t e of c a l l i n g v a r i e s t o some e x t e n t w i t h the number of whales i n the a r e a . S m a l l pods (< 10 members) f o r a g i n g a l o n e u s u a l l y c a l l i n t e r m i t t e n t l y a t r a t e s of < 15 c a l l s / m i n and o f t e n spend the m a j o r i t y of time i n s i l e n c e . A g g r e g a t i o n s of s e v e r a l pods (> 30 a n i m a l s ) tend t o c a l l - more c o n s i s t e n t l y and a t h i g h e r r a t e s . Changes i n the d i r e c t i o n of p r o g r e s s i o n of a f o r a g i n g pod o f t e n occur q u i c k l y and i n v o l v e a l l members of the group. These 35 F i g u r e 7. Frequency h i s t o g r a m of d i s c r e t e , v a r i a b l e and a b e r r a n t c a l l o c c u r r e n c e d u r i n g f o u r a c t i v i t y s t a t e s of pods A1, A4 and A5. S i g n i f i c a n t d i f f e r e n c e s d e t e r m i n e d from ANOVA w i t h S c h e f f e ' s t e s t as f o l l o w s : D i s c r e t e C a l l s : F o r a g i n g and t r a v e l l i n g > s o c i a l i z i n g (p < 0.001) F o r a g i n g and t r a v e l l i n g > beach r u b b i n g (p < 0.05) V a r i a b l e C a l l s : S o c i a l i z i n g and beach r u b b i n g > f o r a g i n g (p < 0.001) S o c i a l i z i n g > t r a v e l l i n g (p < 0.001) Beach r u b b i n g > t r a v e l l i n g (p < 0.05) A b e r r a n t C a l l s : S o c i a l i z i n g > f o r a g i n g and t r a v e l l i n g (p < 0.001) 100 -i 80 -6 0 -40 -20 -0 • = Discrete calls LUI = Variable calls HH = Aberrant discrete calls Foraging n= 12320 Travelling 1233 Socializing 5763 Beach Rubbing 744 calls ACTIVITY 37 t u r n s a re t y p i c a l l y accompanied by c a l l i n g . Some synchronous t u r n s were obser v e d i m m e d i a t e l y f o l l o w i n g the onset of c a l l i n g a f t e r an i n t e r v a l of s i l e n c e . O t h e r s took p l a c e d u r i n g p e r i o d s of c o n s t a n t c a l l i n g , w i t h no i n c r e a s e or d e c r e a s e i n c a l l r a t e apparent e i t h e r b e f o r e or a f t e r the t u r n . A few t u r n s were c a r r i e d out i n the absence of any d e t e c t a b l e c a l l s . Bouts of c a l l i n g w i t h i n a f o r a g i n g pod appear t o r e p r e s e n t exchanges of s i g n a l s among i t s s c a t t e r e d members. O f t e n , c a l l s i n a s e r i e s a r e heard at w i d e l y d i f f e r e n t i n t e n s i t i e s and w i t h d i f f e r e n t r e v e r b e r a t i o n p a t t e r n s , s u g g e s t i n g the involvement of s e v e r a l a n i m a l s a t d i f f e r e n t l o c a t i o n s . S t e r e o p h o n i c r e c o r d i n g s r e i n f o r c e d t h i s i m p r e s s i o n . A number of i n s t a n c e s of i n d i v i d u a l whales and subgroups t a k i n g salmon were obser v e d and m o n i t o r e d a c o u s t i c a l l y a t c l o s e range. In each c a s e , the a n i m a l s were s i l e n t w h i l e p u r s u i n g the f i s h , except f o r p e r i o d i c b u r s t s of e c h o l o c a t i o n - t y p e c l i c k s . The whales g e n e r a l l y resumed c a l l i n g o n l y a f t e r making the k i l l . B) T r a v e l l i n g V o c a l i z a t i o n u s u a l l y o c c u r s a t h i g h r a t e s w h i l e t r a v e l l i n g . Rates i n e x c e s s of 50 p u l s e d c a l l s / m i n were r e c o r d e d from pods A1, A4 and A5 w h i l e t r a v e l l i n g t o g e t h e r . Complete s i l e n c e was observ e d on a few o c c a s i o n s when a pod was t r a v e l l i n g r a p i d l y as a compact group, d i v i n g and s u r f a c i n g s i m u l t a n e o u s l y . The p r o p o r t i o n s of d i f f e r e n t p u l s e d sound t y p e s d i d not d i f f e r s i g n i f i c a n t l y from th o s e i n f o r a g i n g c o n t e x t s ( F i g . 7 ) . O v e r a l l , 94.0% were d i s c r e t e c a l l s , w i t h the remainder made up 38 of v a r i a b l e (5.8%) and aberrant (0.2%) c a l l s . The l a t t e r two sound types, along with w h i s t l e s , were heard only when s o c i a l i z i n g a c t i v i t i e s accompanied t r a v e l l i n g behaviour. C) Group-Resting G r o u p - r e s t i n g behaviour i s g e n e r a l l y accompanied by low l e v e l s of v o c a l a c t i v i t y . In most cases, r e s t i n g whales become completely s i l e n t , except f o r sporadic c l i c k s . On other o c c a s i o n s , almost continuous l o w - l e v e l w h i s t l i n g can be heard from r e s t i n g pods, but only w i t h i n 100-200 m of the group. At times, d i s c r e t e c a l l s are g i v e n , g e n e r a l l y at low r a t e s of < 20/min, in a d d i t i o n to q u i e t w h i s t l i n g . Sound production d u r i n g g r o u p - r e s t i n g v a r i e s with the animals' s t a t e of a r o u s a l . F u l l y r e s t i n g whales, grouped t i g h t l y and d i v i n g as a s i n g l e u n i t , are most o f t e n s i l e n t . Whales that are r e s t i n g " l i g h t l y " , or are at somewhat higher l e v e l s of a r o u s a l , are more l i k e l y to emit w h i s t l e s and c a l l s . S p a t i a l cohesion i s l o o s e r at such times, but pod members s t i l l tend to synchronize d i v e s and s u r f a c i n g s . As w i l l be shown in S e c t i o n 4, c e r t a i n d i s c r e t e c a l l types predominate i n , but are not e x c l u s i v e of, these low-arousal c o n t e x t s . G r o u p - r e s t i n g bouts terminate with e i t h e r abrupt or gradual t r a n s i t i o n s i n t o other a c t i v i t y c a t e g o r i e s . P r o t r a c t e d changes i n t o s o c i a l i z i n g are accompanied by i n c r e a s e s i n w h i s t l i n g and v a r i a b l e and aberrant c a l l p r o d u c t i o n . Foraging behaviour o f t e n develops slowly from g r o u p - r e s t i n g as pod members s c a t t e r and become asynchronous in t h e i r d i v i n g . Concurrent v o c a l behaviour 39 a t such t i m e s s h i f t s from s i l e n c e or l o w - a r o u s a l d i s c r e t e c a l l s t o c a l l t y p e s t y p i c a l of f o r a g i n g a c t i v i t y . Abrupt t r a n s i t i o n s from g r o u p - r e s t i n g t o f o r a g i n g were always accompanied by the sudden onset of v o c a l i z a t i o n i n v o l v i n g a v a r i e t y of d i s c r e t e c a l l t y p e s . D) S o c i a l i z i n g Whales t e n d t o be v e r y v o c a l w h i l e s o c i a l i z i n g . P e r i o d s of s i l e n c e a r e both b r i e f and i n f r e q u e n t . V a r i a b l e c a l l s and a b e r r a n t v e r s i o n s of d i s c r e t e c a l l s and w h i s t l e s a r e used more o f t e n d u r i n g s o c i a l i z i n g a c t i v i t i e s than w h i l e f o r a g i n g or t r a v e l l i n g ( F i g . 7 ) . V a r i a b l e c a l l s c o m p r i s e d 30.5% of s o c i a l s i g n a l s g i v e n by s o c i a l i z i n g A-pods, compared t o 4.3% and 5.8% d u r i n g f o r a g i n g and t r a v e l l i n g , r e s p e c t i v e l y . The p r o p o r t i o n of v a r i a b l e c a l l s r e ached almost 100% f o r b r i e f (< 5 min) p e r i o d s d u r i n g i n t e n s e s o c i a l i z i n g . A b e r r a n t c a l l s , r e l a t i v e l y uncommon i n any c o n t e x t , were s i g n i f i c a n t l y more f r e q u e n t d u r i n g s o c i a l i z i n g (4.0% of c a l l i n g ) than f o r a g i n g (0.5%) and t r a v e l l i n g (0.2%) ( F i g . 7 ) . W h i s t l e s a r e abundant throughout most s o c i a l i z i n g b o u t s . O f t e n , they a r e the o n l y s i g n a l s produced w h i l e a s o c i a l i z i n g pod i s underwater. C a l l i n g w i t h p u l s e d s i g n a l s resumes once the whales r e t u r n t o the s u r f a c e . E) Beach:Rubbing Sound p r o d u c t i o n d u r i n g beach r u b b i n g a c t i v i t i e s i s s i m i l a r t o t h a t i n s o c i a l i z i n g c o n t e x t s , a l t h o u g h the r a t e of c a l l i n g tends t o be more v a r i a b l e . Whales o f t e n l a p s e i n t o s i l e n c e 40 while slowly rubbing, or emit occasional low-arousal discrete c a l l s and whistles. When animals are rubbing vigorously, c a l l rates increase to levels comparable to other a c t i v i t i e s . As in s o c i a l i z i n g , the use of variable pulsed c a l l s i s greater than in foraging and t r a v e l l i n g (Fig. 7). Aberrant c a l l s appear to be more frequent, although -not to a s t a t i s t i c a l l y s i g n i f i c a n t extent, and whistles are also common. Loud, broadband sounds caused by animals pushing and s l i d i n g through the loose pebbles are heard throughout rubbing episodes. The above analyses indicate that the abundance of variable c a l l s , aberrant c a l l s , and whistles is d i r e c t l y related to the degree of s o c i a l a c t i v i t y within pods. Highly s o c i a l behaviours such as beach rubbing and the various interactions during s o c i a l i z i n g bouts are accompanied by the greatest incidence of these sound types. Such signals are rarely heard from foraging or t r a v e l l i n g groups unless some animals (often juveniles) are physically interacting or playing nearby. As the proportion of members engaged in s o c i a l a c t i v i t i e s increases, so too do these sounds. 4. Correlation of Discrete C a l l Types with A c t i v i t y Context Although most resident pods have quite d i f f e r e n t repertoires of discrete c a l l s (Part I I ) , the manner of c a l l use by these groups i s , in most cases, very s i m i l a r . Three pods, A1, A4 and A5, were selected from the 16 resident pods recorded for detailed analysis of cor r e l a t i o n between discrete c a l l occurrence and behaviour. These pods were the most commonly 41 observed and recorded in this study, accounting for 234 (54.9%) of the 426 resident pod encounters. Examples are also drawn from the acoustic behaviour of certain other resident pods. The following description includes a l l f i v e major a c t i v i t y categories discussed above, as well as three additional contexts not previously defined. These are (1) large aggregations of pods, (2) instances of pods meeting, and (3) cases of very high arousal or excitement. The C a l l Repertoire of the A-pods: Pods A1, A4 and A5 contained 14, 7 and 12 individuals, respectively, in 1983. Details of age and sex compositions are given in Part I I . The three groups are very closely associated. On the 110 days that one or more of the A-pods were encountered, a l l three were present on 43 occasions (39.1%), two were together on 25 days (22.7%), and on 42 days (38.2%) only a single A-pod was present. This close association i s re f l e c t e d in their very similar repertoires of discrete c a l l s . The three pods together share 10 c a l l types, N2, N3, N4, N5, N7, N8, N9, N10, N1 1 and N12. Pods A1 and A4 produce a further c a l l , N1,, which is not given by A5, while A4 and A5 share c a l l N13, not produced by A1 pod. Pods A4 and A5 each have an additional pod-s p e c i f i c c a l l type, N19 and N17, respectively. F i n a l l y , two more c a l l s , N27 and N47, are given by A1 pod alone. For descriptions and i l l u s t r a t i o n s of these and other resident pod c a l l types, as well as an explanation of the c a l l numbering system, see Part I I . 42 Based on comparisons of c a l l s g i v e n i n a s t a n d a r d f o r a g i n g c o n t e x t , I det e r m i n e d t h a t pods A1, A4 and A5, i n a d d i t i o n t o h a v i n g p o d - s p e c i f i c c a l l s , d i f f e r s i g n i f i c a n t l y i n t h e i r f r e q u e n c y of use of 6 of the 10 shared c a l l t y p e s ( P a r t I I ) . For t h i s r e a s o n , o n l y those e n c o u n t e r s where a l l t h r e e A-pods were p r e s e n t were used i n the c a l l o c c u r r e n c e v e r s u s a c t i v i t y a n a l y s e s . C a l l s N13, N17, N19, N27 and N47 were e x c l u d e d from s t a t i s t i c a l comparisons owing t o t h e i r low r a t e of o c c u r r e n c e i n any c o n t e x t . C a l l R e p e r t o i r e s of I n d i v i d u a l Whales: From f i e l d r e c o r d i n g s u s i n g a s i n g l e , o m n i - d i r e c t i o n a l hydrophone, i t i s d i f f i c u l t t o determine which a n i m a l s a r e p r o d u c i n g sounds. One of the main q u e s t i o n s which a r o s e e a r l y i n the study was, does each member of a pod produce the e n t i r e r e p e r t o i r e of d i s c r e t e c a l l s t h a t i s r e c o r d e d i n the presence of the group? C a l l s r e c o r d e d from i n d i v i d u a l s t r a v e l l i n g and v o c a l i z i n g a t some d i s t a n c e from t h e i r pod suggested t h a t t h i s i s the c a s e . For example, one s h o r t r e c o r d i n g of an a d u l t male, B2, swimming a l o n e c o n t a i n s a l l but one c a l l t y p e i n the 1 0 - c a l l r e p e r t o i r e of B pod - the m i s s i n g c a l l (N20) i s uncommon, c o m p r i s i n g o n l y 4.1% of the c a l l p r o d u c t i o n of the pod ( P a r t I I ) . F u r t h e r e v i d e n c e i s c o n t a i n e d i n r e c o r d i n g s of 6 c a p t i v e k i l l e r whales, p r o v i d e d by M. Dahlheim and D. B a i n . These whales, 4 females and 2 males, were t a k e n from 2 c a p t u r e s i n 1968 and 1969, a t Pender Harbour, B.C. The 1969 c a p t u r e i s 43 known t o have i n v o l v e d A5 pod ( B i g g 1982), but t h e r e i s no p h o t o g r a p h i c documentation of the pod taken i n 1968. However, j u d g i n g from c a l l s produced by i n d i v i d u a l s from the e a r l i e r c a p t u r e , A5 pod was i n v o l v e d i n t h i s case as w e l l . The c a l l s g i v e n by the 6 c a p t i v e whales a r e l i s t e d i n Table I . A t o t a l of 10 c a l l s was r e c o r d e d , but not a l l were p r e s e n t i n the s h o r t samples a v a i l a b l e f o r each i n d i v i d u a l . A l l 10 c a l l t y p e s a r e commonly g i v e n by a l l t h r e e A-pods, but s t r u c t u r a l v a r i a t i o n s i n c a l l N9 (see P a r t I I ) a r e t y p i c a l of A5 pod a l o n e . C a l l s N13 and N17, two uncommon c a l l s which amount t o 1.4% and 2.8%, r e s p e c t i v e l y , of A5-pod's r e c e n t c a l l p r o d u c t i o n ( P a r t I I ) , were not g i v e n by any of the 6 whales. The im p o r t a n t f e a t u r e t o n o t e , however, i s t h a t no c a l l i n T a b l e I was g i v e n e x c l u s i v e l y by one sex. A) F o r a g i n g The f r e q u e n c y of o c c u r r e n c e of a l l 16 d i s c r e t e c a l l t y p e s d u r i n g f o r a g i n g c o n t e x t s was d e t e r m i n e d from 67 10-min p e r i o d s sampled from 27 en c o u n t e r s w i t h the t h r e e A-pods between J u l y , 1978, and August, 1981. F r e q u e n c i e s were c a l c u l a t e d i n d e p e n d e n t l y f o r each sample t i m e - p e r i o d , and the d e s c r i p t i v e s t a t i s t i c s of the s e v a l u e s a r e l i s t e d i n Ta b l e I I . F i v e c a l l t y p e s , N2, N4, N5, N7 and N9, were c o n s i s t e n t l y the most abundant, b e i n g p r e s e n t i n a l l 67 sample t i m e - p e r i o d s . Of t h e s e f i v e c a l l s , which t o g e t h e r comprised 78.5% of o v e r a l l c a l l p r o d u c t i o n , c a l l N4 was the most common (31.2%) and N5 the l e a s t ( 9 . 2 % ) . Of the r e m a i n i n g 11 c a l l s i n the r e p e r t o i r e , 4 44 T a b l e I . A-pod c a l l t y p e s produced by c a p t i v e whales. R e c o r d i n g of "Bonnie" p r o v i d e d by D. B a i n . A l l o t h e r s p r o v i d e d by M. Dahlheim. Whales were sampled from two c a p t u r e s , March, 1968, and December, 1969, a t Pender Harbour, B.C. The second c a p t u r e was d e t e r m i n e d by B i g g (1982) u s i n g p h o t o g r a p h i c e v i d e n c e t o have i n v o l v e d A5 pod. C a l l Name Sex Capture Oceanarium* N2 N3 N4 N5 N7 N8 N9 N10 N i l N12 Orky M 1968 ML X X X X X X X X X Bonnie F 1968 MW X X X X X X X X Kianu F 1968 MW X X X X X Cor ky F 1969 ML X X X X X X X Yaka F 1969 MW X X X X X X X X Nepo M 1969 MW X X X X X X X * ML = Marineland of the P a c i f i c , C a l i f o r n i a MW = Marine World A f r i c a U.S.A., C a l i f o r n i a T a b l e I I . Frequency of o c c u r r e n c e of d i s c r e t e c a l l t y p e s produced by pods A l , A4 and A5 w h i l e f o r a g i n g . Sample s i z e (n) i s number of 10-min sample p e r i o d s c o n t a i n i n g one or more examples of each c a l l , out of a t o t a l of 67 time p e r i o d s . D e s c r i p t i v e s t a t i s t i c s based on p r o p o r t i o n s c a l c u l a t e d i n d e p e n d e n t l y f o r each sample p e r i o d . C a l l n (%) Mean SD Min Max N1 62 (92.5) 4.15 3.62 0 17.90 N2 67 (100) 12.24 5.80 2.25 40.98 N3 40 (59.7) 3.14 4.72 0 27.06 N4 67 (100) 31.21 9.31 9.09 54.54 N5 67 (100) 9.21 4.70 1.61 21.81 N7 67 (100) 11.12 5.58 1 .63 24. 18 N8 63 (94.0) 4.40 2.90 0 1 3.75 N9 67 (100) 14.73 6.64 0.82 34. 17 N1 0 61 (91.1) 2.67 2.05 0 10.91 N1 1 37 (55.2) 1 .86 1 .51 0 6.34 N12 62 (92.5) 4.31 3.20 0 1 4.92 N1 3 40 (59.7) 0.81 1 .08 0 5.64 N17 28 (41.8) 0.94 1 .73 0 7.73 N1 9 19 (28.4) 0.27 0.63 0 3. 16 N27 13 (19.4) 0.22 0.51 0 2.24 N47 41 (61.2) 1 .79 2.87 0 16.48 47 ( N I , N8, N10 and N12) were r e c o r d e d i n > 90% of the time p e r i o d s , w h i l e o n l y 3 c a l l s (N17, N19 and N27) were r e p r e s e n t e d i n < 50% of the samples. B) T r a v e l l i n g F i v e 10-min time p e r i o d s , c o n t a i n i n g 1160 c a l l s , were sampled from t r a v e l l i n g e p i s o d e s i n v o l v i n g pods A1, A4 and A5. The f r e q u e n c y d i s t r i b u t i o n of these c a l l s i s shown i n F i g . 8. There were no s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s i n the o c c u r r e n c e of c a l l t y p e s between f o r a g i n g and t r a v e l l i n g c o n t e x t s ( T a b l e I I I ) . In c o n t r a s t t o t h i s s i t u a t i o n , however, pods J and L of the s o u t h e r n r e s i d e n t community appear t o change markedly the n a t u r e of d i s c r e t e c a l l use when t r a v e l l i n g . Pod J , f o r example, has a t o t a l r e p e r t o i r e of 17 c a l l t y p e s (see P a r t I I f o r a d e s c r i p t i o n of t h e s e c a l l s ) . D u r i n g f o r a g i n g , exchanges were dominated by c a l l S1 ( 5 2 . 4 % ) , f o l l o w e d by S4 (16.6%) and S7 ( 6 . 2 % ) . W h i l e t r a v e l l i n g , however, S2, S44 and S42 became the predominant c a l l s , c o m p r i s i n g 38.3%, 19.2% and 14.5% of the t o t a l , r e s p e c t i v e l y . A n a l y s e s of v a r i a n c e were a p p l i e d t o p r o p o r t i o n d a t a f o r c a l l s S1, S2, S3, S4, S7, S42 and S44 t o determine the s i g n i f i c a n c e of t h e s e d i f f e r e n c e s ( o t h e r c a l l t y p e s o c c u r r e d t o o i n f r e q u e n t l y i n one or both c o n t e x t s t o w a r r a n t a n a l y s i s ) . A t o t a l of 30 10-min time p e r i o d s was sampled from f o r a g i n g bouts and 9 time p e r i o d s from e p i s o d e s of t r a v e l . A l l 7 c a l l t y p e s d i f f e r e d a t t h e p < 0.001 l e v e l . The reason f o r t h i s d i f f e r e n c e i n the p a t t e r n s of v o c a l a c t i v i t y between s o u t h e r n and n o r t h e r n 48 F i g u r e 8. Frequency h i s t o g r a m s of d i s c r e t e c a l l t y p e s produced by pods A1, A4 and A5, d u r i n g d i f f e r e n t a c t i v i t y s t a t e s . Group r e s t i n g i s not shown because of near t o t a l r e l i a n c e on the N3 c a l l c a t e g o r y d u r i n g v o c a l b o u t s . S i g n i f i c a n t d i f f e r e n c e s i n c a l l o c c u r r e n c e between p a i r s of a c t i v i t i e s shown i n T a b l e I I I . 49 40-, 30 20-10-> o z LU D o LU CC LL LLi o cc LU CL 30 20-10-20 10-1 0 20-10-0-20-10-0 30 20-10-0- 1 — r Foraging n= 11724 calls Travelling n= 1160 calls Socializing n=4008 calls H L Beach Rubbing n= 578 calls Large Aggregations n= 1450 calls Pods Meeting n= 461 calls i 1 N1 N2 N3 N4 N5 N7 N8 N9 N10 N11 N12 N13 N17 N19 N27 N47 CALL TYPE 50 communities i s not known. C) Group-Resting As mentioned previously, group-resting whales are either s i l e n t , or produce whistles and discrete c a l l s . In the case of pods A l , A4 and A5, these discrete c a l l s consist almost e n t i r e l y of c a l l N3, with occasional use of N12, a c a l l related in structure to N3. Bouts of exclusive N3 c a l l i n g extend into other contexts with low-arousal l e v e l s . An example i s when pods cruise slowly in what appears to be a state intermediate between resting and foraging. N3's are also heard from subgroups resting in the presence of active whales, especially during s o c i a l i z i n g a c t i v i t i e s . It should be noted that N3 c a l l s are given occasionally in apparent high-arousal contexts such as active foraging and t r a v e l l i n g (Fig. 8). Low-arousal, or resting c a l l s are produced by most resident pods. Usually only 1 or 2 di f f e r e n t c a l l types are used, but in the case of 3 a c o u s t i c a l l y - s i m i l a r pods G, 111 and 131, a t o t a l of 6 c a l l s occur predominantly in low-arousal contexts. At the opposite extreme, no c a l l s c h a r a c t e r i s t i c of resting were i d e n t i f i e d for J pod of the southern resident community. On the 7 occasions group-resting was observed in this pod, the animals were s i l e n t . Similar observations were made by Hoelzel and Osborne (in press) and R. Osborne (pers. comm.) for resting in southern pods. 51 D) S o c i a l i z i n g As d e s c r i b e d p r e v i o u s l y , o n l y 65.5% of the s o c i a l s i g n a l s g i v e n by the A-pods w h i l e s o c i a l i z i n g were d i s c r e t e c a l l s , w i t h the remainder made up of v a r i a b l e and a b e r r a n t c a l l s . An e x a m i n a t i o n of the d i s t r i b u t i o n of d i s c r e t e c a l l t y p e s from 23 10-min time p e r i o d s sampled from s o c i a l i z i n g c o n t e x t s ( F i g . 8) r e v e a l s s e v e r a l s i g n i f i c a n t d i f f e r e n c e s (Table I I I ) . C a l l s N3, N5, N7, N8 and N11 were g i v e n more f r e q u e n t l y than d u r i n g f o r a g i n g , and of t h e s e , N3 a l s o o c c u r r e d more o f t e n than w h i l e t r a v e l l i n g . E) Beach Rubbing Of the s i g n a l s p r e s e n t i n 5 10-min time p e r i o d s r e c o r d e d d u r i n g beach r u b b i n g , 75.8% were d i s c r e t e c a l l s . C a l l type o c c u r r e n c e d i d not d i f f e r from f o r a g i n g , t r a v e l l i n g , or s o c i a l i z i n g , w i t h the e x c e p t i o n s of N3 and N12. C a l l N12 comprised 10.9% of the t o t a l , h i g h e r than i n any o t h e r c o n t e x t ( F i g . 8 ) , a l t h o u g h the d i f f e r e n c e s were s i g n i f i c a n t o n l y f o r f o r a g i n g , s o c i a l i z i n g and l a r g e m u l t i - p o d a g g r e g a t i o n s (Table I I I ) . C a l l N3 was more common d u r i n g beach r u b b i n g than d u r i n g f o r a g i n g or t r a v e l l i n g . F) Other C o n t e x t s 52 Table I I I . D i f f e r e n c e s in c a l l occurrence d u r i n g a c t i v i t y c a t e g o r i e s . S i g n i f i c a n c e l e v e l s based on one-way ANOVA with Scheffe's p a i r - w i s e comparison of means. F = Foraging T = T r a v e l l i n g S = S o c i a l i z i n g BR = Beach Rubbing LA = Large Multi-Pod Aggregations PM = Pods Meeting C a l l S i g n i f i c a n c e l e v e l p < 0.001 p < 0.01 p < 0.05 NI N2 N3 PM > S PM > F PM > LA PM > BR PM > T S > F S > T BR > F BR > T N4 N5 N7 N8 N9 N10 N i l N12 F > PM LA LA LA LA BR F S T S > F BR > LA T > PM PM > BR S > F S > PM S > F LA > PM PM > F BR > F BR > S 5 4 Large Aggreqations: To examine the effect of large multi-pod aggregations on c a l l production of the A-pods, samples were drawn from 3 encounters where 5 or more additional pods were present in the immediate area. These encounters included representative pods from the two other main dial e c t groups of the northern resident community (see Part I I ) . On one of the three occasions, 7 pods accompanied the A-pods, creating an assemblage of more than 100 whales. At such times, vocal a c t i v i t y was intense and c a l l i d e n t i f i c a t i o n was made d i f f i c u l t due to frequent overlapping of c a l l s . The d i s t r i b u t i o n of 1450 A-pod c a l l s i d e n t i f i e d in 11 - 10-min time periods i s generally similar to those described above for other a c t i v i t i e s (Fig. 8). A major difference, however, can be seen in c a l l N11, an uncommon c a l l in most contexts, which comprised 14.1% of the t o t a l c a l l s produced during large-aggregation contexts. This i s s i g n i f i c a n t l y greater (p < 0.001) than a l l contexts except pods meeting, described below. The only other difference seen i s in c a l l N9, which occurred more frequently (p < 0.05) than during the pods-meeting context (Table I I I ) . Pods Meet ing: On occasion, pods or groups of pods which had been t r a v e l l i n g independently approached and met each other, with a wide range of behavioural responses. Often one of the two groups changed i t s course and joined the other, sometimes 55 c h a n g i n g i t s a c t i v i t y t o t h a t of the pod i t was j o i n i n g . M e e t i n g s among the t h r e e c l o s e l y - r e l a t e d A-pods u s u a l l y o c c u r r e d w i t h l i t t l e change i n group a c t i v i t e s or l e v e l of a r o u s a l . However, meetings between the A-pods and o t h e r n o r t h e r n r e s i d e n t groups were o f t e n accompanied by a d r a m a t i c change i n b e h a v i o u r and h i g h l e v e l s of e x c i t e m e n t . Sounds were sampled from one of t h e s e a c t i v e meetings t o i n v e s t i g a t e the A-pods' c a l l use i n t h i s c o n t e x t . The meeting a n a l y z e d here i n v o l v e d the A-pods and B pod, a f e l l o w n o r t h e r n r e s i d e n t group of 8 whales. I t can be c o n s i d e r e d r e p r e s e n t a t i v e of a h i g h - a r o u s a l meeting. C a l l i n g was e x t r e m e l y i n t e n s e throughout the m e e t i n g , a t t i m e s r e a c h i n g r a t e s of 90-95 c a l l s / m i n . The f r e q u e n c y d i s t r i b u t i o n of A-pod d i s c r e t e c a l l s r e c o r d e d d u r i n g two 10-min samples from t h i s meeting a r e shown i n F i g . 8. C a l l N2 was by f a r the most abundant c a l l , c o m p r i s i n g 38.2% of the t o t a l . T h i s p r o p o r t i o n was s i g n i f i c a n t l y g r e a t e r than i n any o t h e r a c t i v i t y c a t e g o r y (Table I I I ) . C a l l s N5 and N11 were a l s o r e l a t i v e l y abundant d u r i n g the meeting c o n t e x t . D i s c r e t e c a l l s produced d u r i n g h i g h - a r o u s a l meetings and e x c i t e d c o n t e x t s i n g e n e r a l (see below) t e n d t o be e m i t t e d r a p i d l y ( i . e . , s h o r t e r d u r a t i o n ) and a t h i g h e r p i t c h e s ( F i g . 9 ) . Frequency and d u r a t i o n measurements f o r c a l l N2 d u r i n g e x c i t e d v e r s u s f o r a g i n g c o n t e x t s are d e s c r i b e d i n Table IV. Most d u r a t i o n , measurements are s i g n i f i c a n t l y s h o r t e r i n the e x c i t e d v e r s i o n s and s i d e b a n d i n t e r v a l s ( d i r e c t l y r e l a t e d to p i t c h ) are h i g h e r . 56 Figure 9. Examples of c a l l s N2 and N16 given in t y p i c a l and excited forms. A = C a l l N2, produced by pods A1, A4 and A5 B = C a l l N16, produced by B pod 57 I 1 1 0 500 ms 58 Table IV. Comparison of c a l l N2 structure during normal versus excited contexts. The d i f f e r e n t subdivisions, or 'parts' of the c a l l are i d e n t i f i e d in Figure 9. Abbreviations: Nor = normal renditions sampled from pods A1, A4 and A5. Exc = excited renditions from encounter with same pods. SBI = sideband interval f = frequency 59 Measurement Type Mean C.V. Min Max n P D u r a t i o n (ms) Nor 680 19.4 468 1066 86 <0.001 Exc 424 13.3 315 502 30 P a r t 1: Dur (ms) Nor 58 34.5 16 395 86 ns Exc 50 32.4 19 81 30 SBI (Hz) Nor 481 13.1 291 611 71 ns Exc 471 11.4 355 562 30 P a r t 2: Dur (ms) Nor 612 19.9 415 1001 86 <0.001 Exc 374 17.1 259 470 30 S B I , s t a r t (Hz) Nor 1099 10.2 830 1419 86 ns Exc 1088 7.2 873 1246 30 S B I , 1 s t peak Nor 1567 11.8 1179 2098 86 <0.001 (Hz) Exc 1971 9.1 1747 2350 30 S B I , end (Hz) Nor 1819 16.5 1418 2766 85 <0.001 Exc 2419 32.2 1695 4951 30 time to 1 s t Nor 138 34.6 56 265 86 ns peak (Hz) Exc 110 13.2 64 148 30 P a r t 3: Dur (ms) Nor 63 32.9 27 127 60 <0.05 Exc 52 23.8 28 71 22 f , SB2, end (Hz) Nor 6389 8.4 4825 7544 82 <0.001 Exc 7429 12.0 6051 9861 22 Tone: f , s t a r t (Hz) Nor 6389 8.4 4825 7544 82 ns Exc 6148 12.2 3448 7058 25 f , m i d p o i n t (Hz) Nor 7609 13.2 2418 8081 65 ns Exc 8126 2.4 7794 8712 22 60 Excitement: Conditions of intense arousal or excitement were observed occasionally during a l l a c t i v i t y categories. Most cases involved sudden physical interactions between animals, often subadults, both at the surface and underwater. Individuals were seen to chase or lunge at- each other, and c o l l i s i o n s and slapping were also noted. Very l i k e l y many of the fresh body wounds and healed scars that are obviously made by k i l l e r whale teeth result from such apparent altercations or rough play. Discrete c a l l s , given in short and high-pitched forms as described above, were frequent during heightened excitement. Equally c h a r a c t e r i s t i c , however, were d i s t i n c t i v e series of intense signals with rapid up and down pit c h modulations (Fig. 10). These "excitement c a l l s " generally contained from 1 to 20 modulations in serie s . In a sample from the A-pods, modulations lasted an average of 180 ms (sd = 55.4, n = 15) and were separated by brief gaps of 15-132 ms (mean = 60 ms, sd = 40.8, n = 15). Each modulation began at an average pulse rate of 700 Hz (sd = 155.0, n = 30) which increased rapidly to a peak of 1150-2910 Hz (mean = 1854 Hz, sd = 527.7, n = 30), then f e l l off again to a mean of 650 Hz (sd = 105.83, n = 18). Excitement c a l l s with similar structure were recorded from many pods, including members of both resident communities. At times, rapid series of short discrete c a l l s graded into excitement c a l l s through intermediates that contained c h a r a c t e r i s t i c s of both signal types (Fig. 10). This was noted both in f i e l d encounters and recordings of captive animals. 61 Figure 10. Spectrograms of "excitement c a l l s " and c a l l type N1iv modified by high arousal. 0 A = Excitement c a l l s produced by northern resident pods A5, B, and 11, and southern resident pod J. B = C a l l N1 produced by H pod, grading into an excitement c a l l . 62 A. Excitement cal ls A5 p o d B p o d 11 pod J pod B. Cal l N1iv, grading into excitement cal l r o i 500 ms 63 E x citement c a l l s were heard o c c a s i o n a l l y d u r i n g e p i s o d e s of r a p i d t r a v e l l i n g and d u r i n g v i o l e n t p h y s i c a l i n t e r a c t i o n s between i n d i v i d u a l s . 5. P a t t e r n s of D i s c r e t e C a l l O ccurrence From p r e l i m i n a r y a n a l y s i s of r e c o r d i n g s , i t became c l e a r t h a t d i s c r e t e c a l l s o f t e n o c c u r i n r e p e t i t i v e s e r i e s and t h a t a t l e a s t some c a l l t y pes tend t o be g i v e n i n c l o s e a s s o c i a t i o n by i n d i v i d u a l s ( F o r d and F i s h e r 1983). A complete u n d e r s t a n d i n g of c a l l p r o d u c t i o n p a t t e r n s i s confounded the d i f f i c u l t y of i d e n t i f y i n g i n d i v i d u a l s making sounds from o m n i - d i r e c t i o n a l r e c o r d i n g s . At any g i v e n t i m e , one g e n e r a l l y h e a r s s e v e r a l d i f f e r e n t c a l l t y p e s b e i n g p r o d u c e d and, a p p a r e n t l y , responded to by an unknown number of whales i n unknown p o s i t i o n s . Thus, a c c u r a t e d e s c r i p t i o n of the manner i n which c a l l s a r e exchanged w i t h i n a pod must a w a i t r e c o r d i n g s which a l l o w a c c u r a t e l o c a t i o n and i d e n t i f i c a t i o n of sound s o u r c e s ( e . g . , C l a r k and C l a r k 1980) . To examine f u r t h e r the a s s o c i a t i o n s of c a l l t y p e s , a t r a n s i t i o n a n a l y s i s was performed on sequences of c a l l s r e c o r d e d from the A-pods w h i l e f o r a g i n g . T h i s a n a l y s i s i s c o m p l i c a t e d by the same f a c t o r s d e s c r i b e d above. A r e c o r d e d sequence of c a l l s i s l i k e l y t o i n c l u d e s i m u l t a n e o u s c a l l exchanges w i t h i n s e v e r a l subgroups of w hales. The a n i m a l s may be engaged i n d i f f e r e n t b e h a v i o u r s or may be at d i f f e r e n t l e v e l s of a r o u s a l . Because of t h i s l a c k of s t a t i o n a r i t y i n the d a t a , the a n a l y s i s was r e s t r i c t e d t o f i r s t - o r d e r t r a n s i t i o n s o n l y ( S l a t e r 1973). 64 C o n t i n g e n c y t a b l e a n a l y s i s of the t r a n s i t i o n s among 9 common c a l l s r e c o r d e d from the A-pods are p r e s e n t e d i n T a b l e V. C a l l s N3, N11, N13, N17, N19, N27, and N47 a r e not i n c l u d e d due t o t h e i r low frequency of o c c u r r e n c e . A t e s t of o v e r a l l h e t e r o g e n e i t y of the t r a n s i t i o n s r e v e a l e d t h a t t h e r e are h i g h l y s i g n i f i c a n t dependencies among the c a l l s (G = 2867.9, df = 64, p < 0.001). T a b l e V shows two c l e a r t r e n d s among the t r a n s i t i o n s . F i r s t , a g i v e n c a l l type i s most l i k e l y t o be f o l l o w e d by a r e p e t i t i o n of the same c a l l . Thus, c a l l s tend to o ccur i n s e r i e s . T h i s i s t r u e f o r a l l c a l l s except N8, which shows no s i g n i f i c a n t p o s i t i v e or n e g a t i v e tendency t o o ccur r e p e t i t i o u s l y . Second, c a l l s N7 and N8 a r e c l o s e l y a s s o c i a t e d i n t h a t N8's both f o l l o w and precede N7's more o f t e n than e x p e c t e d . T h i s r e f l e c t s the f a c t t h a t N7's and N8's a r e g e n e r a l l y g i v e n t o g e t h e r by i n d i v i d u a l s , w i t h N8's f o l l o w i n g N7's by an average of 2.1 s ( F o r d and F i s h e r 1983). Not a l l N7's are f o l l o w e d by N8's, but N8's never occur w i t h o u t f i r s t b e i n g preceded by one or more N7's. The s i g n i f i c a n t l y h i g h e r i n c i d e n c e of N8 t o N7 t r a n s i t i o n s ( T a ble Vb) r e s u l t s from t h e f r e q u e n t s i m u l t a n e o u s (but asynchronous) e m i s s i o n of N7/N8 p a i r s by s e v e r a l a n i m a l s . To f u r t h e r i n v e s t i g a t e the i n t e r r e l a t i o n s h i p s of d i f f e r e n t c a l l t y p e s , t r a n s i t i o n s between r e p e t i t i o n s of the same c a l l ( t h e d e s c e n d i n g d i a g o n a l i n T a b l e Va) were e l i m i n a t e d t o remove the s t r o n g i n f l u e n c e of t h e s e t r a n s i t i o n s on o t h e r i n t e r a c t i o n s ( S l a t e r 1973, 1983). T h i s t e s t demonstrated t h a t a s s o c i a t i o n s among the n i n e c a l l s examined a r e h i g h l y s i g n i f i c a n t ( c h i - s q u a r e 65 Table V. Contingency t a b l e a n a l y s i s of t r a n s i t i o n s between common c a l l types of pods A l , A4 and A5. A. T r a n s i t i o n frequency matrix f o r 9698 c a l l t r a n s i t i o n s . B. T r a n s i t i o n matrix showing s i g n i f i c a n t departures from a random model at the p < 0.05 l e v e l of s i g n i f i c a n c e (contingency t a b l e a n a l y s i s using the G-s t a t i s t i c ) f o r the data above. + = observed > expected - = observed < expected ns = no s i g n i f i c a n t d i f f e r e n c e A. FOLLOWING CALL NI N2 N4 N5 N7 N8 N9 N10 N12 NI 88 33 104 35 37 6 47 12 4 366 N2 45 361 365 95 148 26 156 30 35 1261 N4 111 360 1486 302 289 47 404 73 126 3198 N5 38 117 262 278 90 11 116 20 32 964 N7 24 ' 117 228 67 292 365 111 14 46 1264 N8 11 51 113 47 107 32 64 8 30 463 N9 46 138 425 110 134 19 522 43 56 1493 N10 9 23 78 26 19 1 32 41 12 241 N12 11 41 124 24 80 3 49 8 108 448 383 1241 3185 984 1196 510 1501 249 449 9698 B. FOLLOWING CALL NI N2 N4 N5 N7 N8 N9 N10 N12 z a w u S 04 NI N2 N4 N5 N7 N8 N9 N10 N12 + ns + ns ns ns ns ns ns ns ns ns + ns ns ns ns ns ns ns -ns ns + + ns + ns ns ns ns ns ns ns ns + ns ns ns ns ns + ns ns 67 = 2415.1, df = 55, p < 0.001). A l l t r a n s i t i o n s were a g a i n t e s t e d f o r d e p a r t u r e from randomness by r e d u c i n g the m a t r i x t o a 2x2 c o n t i n g e n c y t a b l e about each p a i r . These a n a l y s e s ( T a b l e VI) show t h a t 17 of the 72 t r a n s i t i o n s (23.6%) were s i g n i f i c a n t l y more common than e x p e c t e d and 21 (29.2%) were l e s s common ( a l l a t p < 0.01 or l e s s ) . As e x p e c t e d , t h e r e i s a tendency f o r many c a l l t y p e s both t o precede and f o l l o w N4's, the most abundant c a l l i n the r e p e r t o i r e ( F i g . 8 ) . The c l o s e a s s o c i a t i o n of N7's and N8's a l s o a f f e c t s the p r o b a b i l i t y of t r a n s i t i o n s of these c a l l s w i t h o t h e r s i n the r e p e r t o i r e . Another a p p r a i s a l of c a l l a s s o c i a t i o n s was o b t a i n e d by summing p r e c e d i n g / f o l l o w i n g t r a n s i t i o n s f o r each c a l l p a i r ( T a ble Va) and c a l c u l a t i n g an index of a s s o c i a t i o n on the b a s i s of t h i s v a l u e (as d e s c r i b e d i n M a t e r i a l s and Methods). These i n d i c e s ( T a b l e V I I ) r e f l e c t the tendency f o r c a l l s t o occur t o g e t h e r r e g a r d l e s s of the o r d e r i n which they a r e g i v e n . T h i s a n a l y s i s shows t h a t c a l l s N7 and N8 have the h i g h e s t t r a n s i t i o n p r o b a b i l i t y w i t h an index v a l u e of 0.304, c l o s e l y f o l l o w e d by t r a n s i t i o n s between r e p e t i t i o n s of N4 a t 0.303. These " s e l f t r a n s i t i o n s " tend t o have the h i g h e s t a s s o c i a t i o n i n d i c e s , as do t r a n s i t i o n s between most c a l l s (except N7 and N8) and the common c a l l N4. The d a t a i n Table V I I were used t o c r e a t e a c l u s t e r diagram of a s s o c i a t i o n s - between d i f f e r e n t c a l l t y p e s ( F i g . 11). T h i s a g a i n shows t h a t N7 and N8 a r e s t r o n g l y a s s o c i a t e d and t h a t , t o a l e s s e r e x t e n t , c a l l s N2, N4, N5 and N9 tend t o occur t o g e t h e r . C a l l s N1, N10, and N12 a r e weakly a s s o c i a t e d w i t h o t h e r c a l l s . T a b l e V I . T r a n s i t i o n m a t r i x o f common A-pod c a l l s showing s i g n i f i c a n t d e p a r t u r e s from a random model. A n a l y s i s s i m i l a r t o t h a t i n T a b l e V I b , e x c e p t " s e l f t r a n s i t i o n s " (the descending d i a g o n a l i n T a b l e IVa) i s e x c l u d e d , and each t r a n s i t i o n p a i r was t e s t e d u s i n g c h i - s q u a r e w i t h s i g n i f i c a n c e l e v e l s e t a t p < 0.01, as recommended by C h a t f i e l d and Lemon (1971). FOLLOWING CALL NI N2 N4 N5 N7 N8 N9 N10 N12 NI N 2 N4 N5 N7 N8 N9 N10 N12 ns + ns ns + ns + + ns ns + ns ns + ns ns + ns ns ns ns + + ns ns ns ns + ns ns ns + ns ns ns + ns + ns ns + ns ns ns ns ns ns 69 Table VII. Indices of association of common A-pod c a l l s based on t r a n s i t i o n frequencies. See text for additional explanation. CALL NI N2 N4 . N5 N7 N8 N9 N10 N12 NI .133 N2 .056 .169 N4 .077 .206 .303 N5 .063 .111 .172 .167 N7 .043 .123 .146 .082 .135 N8 .021 .050 .055 .044 .304 .034 N9 .059 .127 .225 .109 .106 .049 .211 N10 .038 .041 .056 .043 .025 .013 .051 .091 N12 .021 .052 .088 .046 .085 .038 .064 .032 .137 7 0 Figure 11. Cluster diagram of associations among common c a l l types produced by pods A1, A4 and A5. Diagram i s based on indices of c a l l association given in Table VII. 0.0 0.1 8 0 2 CO < O 0.3 -0.4 -0.5 L N7 N8 N4 N9 N2 N5 N12 N1 N10 CALL TYPE 71a LEAF ?2 MISSED IN NUMBERING. 73 DISCUSSION Many p a r a l l e l s e x i s t between the s o c i a l b e h a v i o u r of odontocete c e t a c e a n s and t e r r e s t r i a l s o c i a l mammals, e s p e c i a l l y the u n g u l a t e s and p r i m a t e s ( T a y l e r and Saayman 1972; Wursig 1978; Saayman and T a y l e r 1979; W e l l s e t a l . 1980). T h i s may a l s o be t r u e of t h e i r s o c i a l s i g n a l l i n g . The complex communication p a t t e r n s of the h i g h e r p r i m a t e s have been the s u b j e c t s of much r e c e n t r e s e a r c h , and t h e r e i s now a good u n d e r s t a n d i n g of some of the major r o l e s p l a y e d by a c o u s t i c s i g n a l l i n g w i t h i n n a t u r a l p r i m a t e s o c i e t i e s (Green 1975a; S e y f a r t h e t a l . 1980; Byrne 1982; Robinson 1982; Waser 1982). I t i s e v i d e n t t h a t t h e r e a r e many s i m i l a r t r e n d s i n the a c o u s t i c b e h a v i o u r of p r i m a t e s and k i l l e r whales. In the f o l l o w i n g d i s c u s s i o n , t h e s e s i m i l a r i t i e s a r e e x p l o r e d i n an attempt t o p r o v i d e a broader p e r s p e c t i v e and i n t e r p r e t a t i o n of the k i l l e r whale communication system. P o t e n t i a l Communicative R o l e s of P u l s e d C a l l s and W h i s t l e s The sounds of k i l l e r whales a r e c o r r e l a t e d w i t h the a n i m a l s ' a c t i v i t y and s o c i a l c o n t e x t s . An e x a m i n a t i o n of these p a t t e r n s p r o v i d e s c l u e s about the communicative f u n c t i o n s and e v o l u t i o n a r y i m p l i c a t i o n s of t h e i r v o c a l i z a t i o n s . One c l e a r t r e n d i n the s o c i a l s i g n a l l i n g of k i l l e r whales c o n c e r n s the use of d i s c r e t e c a l l s v e r s u s v a r i a b l e c a l l s and w h i s t l e s i n d i f f e r e n t c o n t e x t s . When i n d i v i d u a l s or subgroups are d i s p e r s e d and out of s i g h t of one a n o t h e r , t h e i r c a l l i n g c o n s i s t s almost e n t i r e l y of d i s c r e t e c a l l s . T h i s s i t u a t i o n p r e v a i l s d u r i n g 74 f o r a g i n g and t r a v e l l i n g a c t i v i t i e s . Whenever a n i m a l s j o i n t o g e t h e r and i n t e r a c t s o c i a l l y , t h e r e i s an a s s o c i a t e d p r o d u c t i o n of v a r i a b l e p u l s e d c a l l s , a b e r r a n t v e r s i o n s of d i s c r e t e c a l l s , and w h i s t l e s . These t y p e s of sounds a r e g e n e r a l l y heard i n d i r e c t p r o p o r t i o n t o the amount of s o c i a l i z i n g a c t i v i t y i n a pod. A s i m i l a r d i f f e r e n t i a l use of d i s c r e t e v e r s u s v a r i a b l e or "graded" c a l l s i n d i f f e r e n t c o n t e x t s has been observed i n many pr i m a t e s p e c i e s ( M a r l e r 1965, 1968, 1972, 1973, 1976; S t r u h s a k e r 1967; G a u t i e r and G a u t i e r 1977; Oppenheimer 1977; Byrne 1982). In g e n e r a l , d i s c r e t e c a l l s t e n d t o be used i n s i t u a t i o n s i n v o l v i n g l o n g-range communication i n h a b i t a t s where v i s i o n i s l i m i t e d by f o l i a g e or o t h e r o b s t r u c t i o n s . Graded s i g n a l s , on the o t h e r hand, a r e exchanged among c l o s e l y - s p a c e d a n i m a l s . The d i s t i n c t i v e " l o u d c a l l s " used i n maintenance of t e r r i t o r i a l b o u n d a r i e s or i n i n t e r g r o u p s p a c i n g of non-t e r r i t o r i a l p r i m a t e s p e c i e s a r e s t r u c t u r a l l y s p e c i a l i z e d f o r unambiguous i d e n t i f i c a t i o n and l o c a l i z a t i o n over l o n g d i s t a n c e s ( M a r l e r and Tenaza 1977; Waser 1977, 1982; Brown 1982). " C o n t a c t " or "coherence" c a l l s a r e used t o keep t r o o p members i n touch w h i l e out of s i g h t of each o t h e r , and t o c o o r d i n a t e i n t r a g r o u p s p a c i n g and movements. A l t h o u g h t h e s e c a l l s a r e l e s s e l a b o r a t e i n s t r u c t u r e , they a l s o t e n d t o be d i s c r e t e l y d i s t i n c t ( M a r l e r 1968, 1973; Byrne 1981, 1982; Robinson 1982). In a number of s p e c i e s , i n t e r - and i n t r a g r o u p c a l l s have been found t o c o n t a i n f e a t u r e s t h a t are c o n s i s t e n t l y unique t o i n d i v i d u a l s ( e . g . , M a r l e r 1973; M a r l e r and Hobbett 1975; Waser 1977, 1982). 75 E x p e r i m e n t a l s t u d i e s have demonstrated t h a t c o n s p e c i f i c s can p e r c e i v e these minor v a r i a t i o n s and use them t o i d e n t i f y d i f f e r e n t c a l l e r s (Waser 1977; Snowdon and C l e v e l a n d 1980; Cheney and S e y f a r t h 1980). U n l i k e long-range c a l l s , a c o u s t i c s i g n a l s exchanged among p r i m a t e s i n c l o s e - k n i t groups where v i s u a l or p h y s i c a l c o n t a c t i s m a i n t a i n e d do not r e q u i r e such s t r u c t u r a l d i s t i n c t i v e n e s s and s t e r e o t y p y . F a c t o r s such as s i g n a l d e g r a d a t i o n and n o i s e masking have l e s s e f f e c t over s h o r t d i s t a n c e s , and i n f o r m a t i o n can be conveyed s i m u l t a n e o u s l y (and r e d u n d a n t l y ) v i a v i s u a l or t a c t i l e , as w e l l as a u d i t o r y , s i g n a l l i n g . C l o s e - r a n g e c a l l s tend t o be much more v a r i a b l e or graded i n s t r u c t u r e and, as a r e s u l t , have the p o t e n t i a l t o convey more s u b t l e and complex i n f o r m a t i o n , e s p e c i a l l y when used i n c o n c e r t w i t h v i s u a l d i s p l a y s ( M a r l e r 1965; Green 1975a). Graded v o c a l systems a r e e s p e c i a l l y p r e v a l e n t among p r i m a t e s t h a t form l a r g e , o f t e n non-t e r r i t o r i a l groups and r e s i d e i n open h a b i t a t s where v i s i o n i s u n r e s t r i c t e d (Green 1975a; M a r l e r 1976). S p e c i e s w i t h graded c a l l i n g a l s o tend t o have more complex s o c i a l o r g a n i z a t i o n s ( G a u t i e r and G a u t i e r 1977). Underwater v o c a l i z a t i o n appears t o be the best means of i n t e r i n d i v i d u a l communication a v a i l a b l e t o k i l l e r whales f o r most of the t i m e . A l t h o u g h v i s i o n i n the s p e c i e s i s good (White et a l . 1974), water c l a r i t y i s g e n e r a l l y so poor i n the study area t h a t v i s u a l c o n t a c t between a n i m a l s would not be p o s s i b l e beyond ranges of 10-20 m. V i s i o n would, of c o u r s e , be even l e s s e f f e c t i v e a t n i g h t . 76 It seems most probable that discrete c a l l s of k i l l e r whales serve a similar purpose to the contact c a l l s and loud c a l l s of arboreal primates. In addition to keeping individuals in touch while the pod i s dispersed, the c a l l s may coordinate spacing and the d i r e c t i o n and rates of group progression. K i l l e r whale discrete c a l l s share many features with the c a l l s used by dispersed primates. They often contain complex stru c t u r a l components with abrupt s h i f t s in pitch and wideband energy content, both of which enhance their r e c o g n i z a b i l i t y over long distances and background noise, as well as their potential for accurate l o c a l i z a t i o n (Brown 1982). As in primate contact c a l l s (Marler 1968; Gautier and Gautier 1977; Byrne 1982; Robinson 1982), k i l l e r whale c a l l s are produced frequently during periods of a c t i v i t y . Also, the spontaneous emission of a c a l l by one whale often triggers c a l l i n g from other group members, but otherwise the c a l l s e l i c i t l i t t l e overt behavioural response. Whether k i l l e r whale discrete c a l l s convey information about the c a l l e r ' s i d e n t i t y is not yet known, but i t appears l i k e l y . I n d i v i d u a l - s p e c i f i c differences could account for a portion of the s t r u c t u r a l v a r i a b i l i t y within each c a l l category. In a study of the sounds of captive k i l l e r whales, Dahlheim and Awbrey (1982) describe apparent individual differences in rather broad signal categories. However, their analyses involved animals taken from a variety of locations and pods, and therefore are complicated by overriding group-specific differences (see Part I I ) . Hoelzel and Osborne (in press) noted 7 7 d i f f e r e n c e s i n the r e n d i t i o n s of one c a l l by t h r e e members of J pod i n the s o u t h e r n r e s i d e n t community which may r e p r e s e n t i n d i v i d u a l " s i g n a t u r e s " . However, l a r g e r samples from s e v e r a l d i f f e r e n t e n c o u n t e r s would be r e q u i r e d b e f o r e o t h e r f a c t o r s which might a f f e c t c a l l s t r u c t u r e , such as d i f f e r i n g m o t i v a t i o n a l l e v e l s , can be r u l e d o u t . S i g n a t u r e f u n c t i o n has been suggested f o r many of the s t e r e o t y p e d s i g n a l s of s e v e r a l o d o n t o c e t e s p e c i e s r e c o r d e d both i n c a p t i v i t y and i n the w i l d (see review by Herman and T a v o l g a 1980). U n l i k e p r i m a t e s i g n a l s , many of the d i s c r e t e c a l l s of k i l l e r whales c o n t a i n c o n s i s t e n t g r o u p - s p e c i f i c s t r u c t u r a l v a r i a t i o n s ( P a r t I I ) . W i t h i n f o r m a t i o n about group and, p o s s i b l y , i n d i v i d u a l i d e n t i t y , d i s c r e t e c a l l s have an even g r e a t e r p o t e n t i a l f u n c t i o n as e f f e c t i v e cues f o r c o o r d i n a t i n g group a c t i v i t i e s and m a i n t a i n i n g pod c o h e s i o n . V a r i a b l e and a b e r r a n t c a l l s and w h i s t l e s g i v e n by k i l l e r whales may be f u n c t i o n a l l y a nalogous t o the graded v o c a l i z a t i o n s of p r i m a t e s . In both groups, the s i g n a l s a re a s s o c i a t e d w i t h c l o s e p r o x i m i t y between i n d i v i d u a l s and s o c i a l i n t e r a c t i o n ; i n k i l l e r w hales, such c o n t e x t s o c c u r d u r i n g s o c i a l i z i n g and beach-r u b b i n g b e h a v i o u r . These a c t i v i t i e s may be a means of r e -e s t a b l i s h i n g s o c i a l r e l a t i o n s h i p s w i t h i n the group f o l l o w i n g p e r i o d s of d i s p e r s i o n or s e p a r a t i o n . T h i s f u n c t i o n has been suggested f o r s i m i l a r b e h a v i o u r s i n a v a r i e t y of t e r r e s t r i a l mammals ( e . g . , G a u t i e r and G a u t i e r 1977; M a r l e r and Tenaza 1977; Smith e t a l . 1982). Whales o f t e n m i l l q u i e t l y or r e s t c l o s e t o one a n o t h e r , engage i n p h y s i c a l and s e x u a l i n t e r a c t i o n s , and 78 carry out a variety of aerobatics. During such times, s i g n a l l i n g i s probably accomplished through the simultaneous use of v i s u a l , t a c t i l e , and auditory channels, allowing the communication of subtle variations in arousal or other circumstances related to the interactions. The resting, or low-arousal c a l l s given frequently by most resident k i l l e r whale pods during group-resting, s o c i a l i z i n g , and beach rubbing contexts (e.g., c a l l N3, described previously) resemble the "quiet" c a l l s used during play and a f f i l i a t i o n in some primates (Smith et a l . 1982). The production of r e l a t i v e l y high-pitched whistles during these contexts also p a r a l l e l s the trend apparent in many birds and mammals towards the use of high-frequency, pure tonelike sounds in " f r i e n d l y " s o c i a l circumstances (Morton 1 977) . Information Content of Discrete C a l l Types As discussed above, one primary function of discrete c a l l s may be to maintain contact among individuals and to preserve the over a l l cohesion of the pod. However, this i s probably not the only potential function of the c a l l s for two reasons. F i r s t , discrete c a l l s are often produced when pods form compact groups, such as during s o c i a l i z i n g . The requirement for i n t e r i n d i v i d u a l contact and l o c a l i z a t i o n at such times would be expected to be reduced, but c a l l i n g often continues at r e l a t i v e l y high rates. Second, intragroup contact and coordination of movements could be accomplished with the use of one or two c a l l types, as in many primates (Gautier and Gautier 1977; Byrne 1981; Robinson 79 1982). The 16 r e s i d e n t pods, however, each have an average of 10.7 d i s c r e t e c a l l t y p e s . Assuming t h a t d i s c r e t e c a l l s c o n t a i n a d d i t i o n a l i n f o r m a t i o n beyond c o n t a c t and l o c a l i z a t i o n of i n d i v i d u a l s , what might be t h e i r f u n c t i o n ? The a c o u s t i c s i g n a l s of mammals are o f t e n c o n s i d e r e d t o be d i r e c t e x p r e s s i o n s of the v o c a l i z i n g i n d i v i d u a l ' s i n t e r n a l m o t i v a t i o n a l s t a t e o r l e v e l of a r o u s a l (Smith 1977; Gould 1983). T h i s i s e s p e c i a l l y t r u e of s p e c i e s w i t h c o m p a r a t i v e l y s i m p l e s o c i a l o r g a n i z a t i o n s and v o c a l r e p e r t o i r e s . S o c i a l l y - a d v a n c e d mammals such as p r i m a t e s have more complex a c o u s t i c r e p e r t o i r e s which v a r y i n s t r u c t u r e and p a t t e r n of use a c c o r d i n g t o the a n i m a l ' s demeanor or "mood", a r e f l e c t i o n of the u n d e r l y i n g i n t e r n a l s t a t e of the v o c a l i z e r m o d i f i e d by the s p e c i f i c s o c i a l c i r c u m s t a n c e or c o n t e x t e l i c i t i n g the v o c a l i z a t i o n (Green 1975a; Byrne 1982; Robinson 1982). R e c e n t l y , i n c r e a s e d a t t e n t i o n has been g i v e n t o the p o s s i b i l i t y t h a t " s e m a n t i c " s i g n a l s which r e f e r t o or s y m b o l i z e e x t e r n a l f e a t u r e s of the environment may be more w i d e s p r e a d , a t l e a s t among p r i m a t e s , than p r e v i o u s l y thought ( S e y f a r t h e t a l . 1982; M a r l e r 1983; D i t t u s 1984). The e x a m i n a t i o n of d i s c r e t e c a l l o c c u r r e n c e i n d i f f e r e n t c o n t e x t s may shed some l i g h t on the p o t e n t i a l f u n c t i o n of s p e c i f i c s i g n a l s . However, t h i s t a s k i s d i f f i c u l t i n p r a c t i c e owing t o the i n a b i l i t y t o observe the d e t a i l s of many b e h a v i o u r s and i n t e r a c t i o n s underwater. For t h i s r e a s o n , c a l l - t y p e v e r s u s b e h a v i o u r c o r r e l a t i o n s a r e l i m i t e d t o r a t h e r broad a c t i v i t y c o n t e x t s . One c l e a r c o r r e l a t i o n i s e v i d e n t i n the use of 80 certain c a l l s in group-resting and other apparent low-arousal situations. It is interesting, however, that some resident pods, such as A l , A4, and A5, produce only a single resting-type c a l l (N3), while other pods give as many as six di f f e r e n t c a l l s (pods G, 111 and 131) or, apparently, none (J pod), in similar situations. As was pointed out e a r l i e r , resting c a l l s also occur in what appear to be moderate or even high arousal contexts, such as rapid t r a v e l l i n g , pod meetings, or large multi-pod aggregations. Thus, these c a l l s may not be simply generalized expressions of low-arousal states, but perhaps instead are correlated with some form of s o c i a l circumstance which occurs most frequently, but not exclusively, during periods of rest or low-activity l e v e l s . Why some pods have several such c a l l s while others have one or none i s unknown. With the exception of group-resting, discrete c a l l production in most resident pods i s consistent throughout the major a c t i v i t y categories, foraging, t r a v e l l i n g , s o c i a l i z i n g , and beach rubbing. Detailed examination of c a l l i n g by the three A-pods revealed l i t t l e s i g n i f i c a n t v a r i a t i o n in occurrence patterns in these contexts. A l l c a l l types were recorded during each a c t i v i t y , and in r e l a t i v e l y few cases did the proportions of d i f f e r e n t c a l l types vary. The only s i g n i f i c a n t differences were in the use of c a l l s N5, N7, N8 and N11, a l l of which tended to be more frequent in s o c i a l i z i n g contexts, and N12, which was more common during beach rubbing. More pronounced differences were evident during large multi-pod aggregations and meetings of pods. C a l l N2 was produced abundantly during the pods-meeting 81 context, as was N5 and N11. C a l l N2 was also strongly associated with other occasions of extreme excitement during s o c i a l interactions within the A-pods, and occurred intermixed with the "excitement c a l l s " described e a r l i e r . During multi-pod aggregations, c a l l N11 comprised 14.1% of discrete c a l l s , compared to < 2% in most a c t i v i t y contexts. There was no obvious correlation with the occurrence of other c a l l s in the repertoire. From th i s comparison, i t i s apparent that c a l l use by the three A-pods varies to some extent with context. It i s noteworthy, however, that a l l c a l l types were given in a l l a c t i v i t y contexts. Given this general consistency in the A-pods' repertoire, i t i s interesting how dramatically c a l l use changes with a c t i v i t y levels in the southern resident pods. In J pod, for example, c a l l s which were heard rarely or not at a l l during foraging became predominant during episodes of rapid t r a v e l l i n g and high arousal. This difference in patterns of c a l l occurrence between the two resident communities i s surprising and i t s cause unknown, but i t i s consistent with other fundamental acoustic differences in both c a l l structure and use (e.g., the lack of resting c a l l s in the southern residents). Although the analysis of t r a n s i t i o n frequencies between c a l l types demonstrates that c a l l occurrence i s non-random, i t does l i t t l e to reveal the functions of the d i f f e r e n t signals. There is some association of c a l l types in the repertoires of a l l resident pods, usually evident in more frequent tr a n s i t i o n s 82 than e x p e c t e d by chance. While the abundance of some d i s c r e t e c a l l t y p e s may be r e l a t e d t o a r o u s a l , v a r i a t i o n i n m o t i v a t i o n can s t r o n g l y a f f e c t the manner i n which c a l l s a r e produced. C a l l s g i v e n d u r i n g h e i g h t e n e d s o c i a l e x c i t e m e n t , f o r example, tend t o be s h o r t e r and h i g h e r i n p i t c h . T h i s was demonstrated e a r l i e r u s i n g measurements of c a l l N2, but h i g h a r o u s a l appears t o a f f e c t many c a l l t y p e s i n a s i m i l a r way. I t has been shown t h a t g r a d a t i o n s w i t h i n c a l l c a t e g o r i e s of p r i m a t e s a r e r e l a t e d t o both a r o u s a l and the s o c i a l c o n t e x t , and t h a t t h e s e v a r i a t i o n s have meaning t o f e l l o w group members (Byrne 1982). In summary, a l t h o u g h l e v e l s of a r o u s a l may a f f e c t the f r e q u e n c y of use and s t r u c t u r e of some c a l l s i n a pod's r e p e r t o i r e , few c a l l s a re t i e d e x c l u s i v e l y t o any p a r t i c u l a r c i r c u m s t a n c e t h a t I c o u l d i d e n t i f y i n t h i s s t u d y . Does t h i s mean t h a t the use of most d i s c r e t e c a l l s i s independent of c o n t e x t ? T h i s q u e s t i o n cannot be a d d r e s s e d a d e q u a t e l y u s i n g the f i e l d o b s e r v a t i o n s i n t h i s s t u d y , but some c l u e s can be o b t a i n e d from whales i n c a p t i v i t y . As r e p o r t e d e a r l i e r (Table I ) , c a p t i v e i n d i v i d u a l s t a k e n from A5 pod produced many of the c a l l s i n t h e i r p o d - s p e c i f i c r e p e r t o i r e . Even though th e s e whales were i n an u n n a t u r a l s e t t i n g , they were u s u a l l y w i t h o t h e r whales and had the o p p o r t u n i t y t o i n t e r a c t and communicate s o c i a l l y , which might account f o r the o c c u r r e n c e of d i f f e r e n t c a l l s . The same cannot be s a i d f o r the whale "Namu", a mature b u l l c a p t u r e d i n 1965 a t Namu, B.C., and m a i n t a i n e d a l o n e i n a net-pen f o r s e v e r a l months b e f o r e b e i n g j o i n e d by "Shamu", a female taken 83 from a southern resident pod (see Part I I ) . Despite the absence of any s o c i a l interaction or normal environmental stimulus, the whale "Namu" produced a l l but 2 of the 10 discrete c a l l s t y p i c a l l y used by C pod of the northern resident community. "Namu" is known to have been removed from C pod from photographs taken at the time of capture (Bigg, pers. comm.). In addition to having e s s e n t i a l l y the same structure, the c a l l s were given in remarkably similar proportions to those on tapes made in 1964, apparently in the presence of C pod, and to tapes obtained from the pod recently in the course of t h i s study. The two c a l l s not recorded from "Namu" represent only 2.2% of the c a l l s used by C pod today (see Part I I ) . The pattern of c a l l i n g by the whale "Namu" raises the p o s s i b i l i t y that many discrete c a l l types may not be t i e d to any p a r t i c u l a r s o c i a l context or external referent. Different c a l l s may s t i l l r e f l e c t v a r i a t i o n in arousal, but this too i s open to question when one considers the marked differences in c a l l structure that exist within a community of pods. If discrete c a l l s are controlled by basic emotive states, v a r i a b i l i t y of c a l l structure would presumably be limited by genetic constraints to rather conservative l e v e l s . This may be the case for the "excitement c a l l s " given in states of extreme arousal, which seem to have e s s e n t i a l l y the same form regardless of pod or community a f f i l i a t i o n . However, as shown in Part II, discrete c a l l types of pods which associate together d i f f e r in such fundamental ways that i t i s often d i f f i c u l t to identify p o t e n t i a l l y homologous c a l l s in separate pods. Vocal variation 84 on t h i s s c a l e might t y p i c a l l y be ex p e c t e d between s p e c i e s , but not among l o c a l groups. An a l t e r n a t i v e e x p l a n a t i o n f o r the f u n c t i o n of c a l l r e p e r t o i r e s i n k i l l e r whales may be found i n the u n u s u a l group-s p e c i f i c d i a l e c t system which e x i s t s i n the B.C. p o p u l a t i o n . I t i s p o s s i b l e t h a t d i s c r e t e c a l l s s e r v e as c o n t a c t or c o h e s i o n c a l l s , but the a c t u a l c a l l t y p e s used are i r r e l e v a n t f o r t h i s p urpose. A r o u s a l or m o t i v a t i o n a l cues may be conveyed i n s t r u c t u r a l v a r i a t i o n s w i t h i n the c a l l c a t e g o r y and perhaps by c a l l i n g r a t e , but the c a l l type used may be l e s s i m p o r t a n t . I n s t e a d , d i s c r e t e c a l l r e p e r t o i r e s may f u n c t i o n p r i m a r i l y as i n d i c a t o r s of k i n s h i p , and thus be i n v o l v e d i n d e t e r m i n i n g s o c i a l o r g a n i z a t i o n and d i s t r i b u t i o n w i t h i n the p o p u l a t i o n . A l a r g e r e p e r t o i r e of c a l l s t h a t v a r y among pods c o u l d a l l o w the enc o d i n g of d e t a i l e d i n f o r m a t i o n c o n c e r n i n g r e l a t e d n e s s . Among the p o t e n t i a l s e l e c t i v e advantages of such a system would be the a v o i d a n c e of e x c e s s i v e i n b r e e d i n g , or p o s s i b l y the t o l e r a n c e of r e l a t e d pods d u r i n g f e e d i n g or f o r a g i n g a s s o c i a t i o n s . A s i m i l a r h y p o t h e s i s has been proposed t o e x p l a i n r e p e r t o i r e s and d i a l e c t s i n b i r d song by Treisman (1978), but i t i s not s u p p o r t e d by r e c e n t f i e l d s t u d i e s on s e v e r a l b i r d s p e c i e s (Krebs and Kroodsma 1980; McGregor and Krebs 1982). The s o c i a l system and d i a l e c t s of k i l l e r whales a r e q u i t e d i f f e r e n t from any b i r d , however, and the k i n - r e c o g n i t i o n h y p o t h e s i s may be more v a l i d i n t h i s s p e c i e s . F u r t h e r e v i d e n c e and i d e a s r e l a t e d t o t h e h y p o t h e s i s a r e g i v e n i n P a r t I I . PART II ALECTS AND CALL TRADITIONS IN RESIDENT KILLER WHALES 86 INTRODUCTION G e o g r a p h i c a l l y - r e l a t e d v a r i a t i o n of v o c a l i z a t i o n i s much l e s s common i n mammals than i n b i r d s , where i t i s a well-known and widespread phenomenon. R e g i o n a l d i f f e r e n c e s i n b i r d s o n g occur a t two major l e v e l s , (1) as 'geographic v a r i a t i o n ' between i s o l a t e d p o p u l a t i o n s , and (2) as ' d i a l e c t s ' among n e i g h b o u r i n g groups which can p o t e n t i a l l y mix and i n t e r b r e e d . Geographic v a r i a t i o n i s c o n s i d e r e d t o r e s u l t from a c o u s t i c a d a p t a t i o n s t o d i f f e r i n g e n v i r o n m e n t a l c o n d i t i o n s a t each s i t e , or t o r e p r e s e n t f u n c t i o n l e s s c u l t u r a l or g e n e t i c d i v e r g e n c e caused by i s o l a t i o n . D i a l e c t s which d e v e l o p among l o c a l p o p u l a t i o n s , on the o t h e r hand, have g e n e r a l l y - been thought t o have some a d a p t i v e s i g n i f i c a n c e (Krebs and Kroodsma 1980; Payne 1981; Baker 1982; Mundinger 1983). Recent s t u d i e s on some s p e c i e s , however, suggest t h a t t h e s e too may be b y p r o d u c t s of v o c a l l e a r n i n g , p a t t e r n s of d i s p e r s a l or some o t h e r f a c t o r (Mundinger 1983; Payne 1983; T r a i n e r 1983; S l a t e r e t a l . 1984). The o n l y t r u e d i a l e c t s documented i n w i l d mammals occur i n k i l l e r whales ( F o r d and F i s h e r 1982, 1983). E a r l i e r r e p o r t s of d i a l e c t s i n the t h r e a t c a l l s of t h e n o r t h e r n e l e p h a n t s e a l (Mirounga a n g u s t i r o s t r i s ) (LeBoeuf and P e t e r s o n 1969) i n v o l v e d s h o r t - l i v e d phenomena caused by p o p u l a t i o n e x p a n sion and c o l o n i z a t i o n of new r o o k e r i e s (LeBoeuf and P e t r i n o v i c h 1974). These v a r i a n t s no l o n g e r e x i s t today ( S h i p l e y et a l . 1981). V a r i a t i o n s d e s c r i b e d as " d i a l e c t s " have been r e p o r t e d f o r s e v e r a l mammalian s p e c i e s , i n c l u d i n g p i k a s (Ochotona p r i n c e p s ) (Somers 1973), b l a c k - t a i l e d p r a i r i e dogs (Cynomys g u n n i s o n i ) 87 ( S l o b o d c h i k o f f and Coast 1980), and humpback whales (Meqaptera n o v a e a n q l i a e ) (Winn et a l . 1981). In each c a s e , however, the v o c a l d i f f e r e n c e s d e s c r i b e d were between p o p u l a t i o n s i s o l a t e d by ge o g r a p h i c b a r r i e r s or l o n g d i s t a n c e s , and t h e r e f o r e a r e c o r r e c t l y d e f i n e d as ge o g r a p h i c v a r i a t i o n s (Nottebohm 1969, 1972; Grimes 1974; Conner 1980; F o r d and F i s h e r 1983; Payne and Guinee 1983). An unusual case of l o c a l e - s p e c i f i c v a r i a t i o n has been r e p o r t e d i n c a l l s which d e v e l o p e d and s p r e a d w i t h i n t h r e e i s o l a t e d t r o o p s of Japanese monkeys (Macaca f u s c a t a ) as a d i r e c t r e s u l t of a r t i f i c i a l f e e d i n g (Green 1975b). D i a l e c t s a p p a r e n t l y do not occur n a t u r a l l y i n the s p e c i e s , nor have they been r e c o r d e d i n the v o c a l i z a t i o n s of any o t h e r non-human p r i m a t e . Indeed, the c a l l s of p r i m a t e s a r e so c o n s i s t e n t over wide g e o g r a p h i c a r e a s t h a t they a r e o f t e n used as taxonomic markers ( e . g . , M a r s h a l l and M a r s h a l l 1976; Hodun e t a l . 1981; Newman and Symmes 1982; Waser 1982; Oates and Tr o c c o 1983). The e x i s t e n c e of g r o u p - s p e c i f i c v o c a l d i a l e c t s i n k i l l e r whales on the c o a s t of B r i t i s h Columbia was f i r s t d e s c r i b e d i n p r e l i m i n a r y r e p o r t s by F o r d and F i s h e r (1982, 1983). The v o c a l i z a t i o n s produced w i t h i n k i l l e r whale pods c o n s i s t p r e d o m i n a n t l y of r e p e t i t i o u s , d i s c r e t e p u l s e d c a l l s . A n a l y s e s of r e c o r d i n g s made d u r i n g r e p e a t e d e n c o u n t e r s w i t h p h o t o g r a p h i c a l l y - i d e n t i f i e d pods demonstrated t h a t each has a l i m i t e d r e p e r t o i r e of d i s c r e t e c a l l t y p e s which i s c o n s t a n t over a number of y e a r s . Some pods share c a l l t y p e s , w h i l e o t h e r s have e n t i r e l y d i f f e r e n t r e p e r t o i r e s . 88 In t h i s c h a p t e r , a d e s c r i p t i o n i s g i v e n of the c a l l r e p e r t o i r e s of a l l 16 pods which comprise the r e s i d e n t p o p u l a t i o n i n B.C. c o a s t a l w a t e r s . The d e s c r i p t i o n i s based on r e c o r d i n g s made between 1978 and 1983, as w e l l as a number of h i s t o r i c a l r e c o r d i n g s made by o t h e r s of both w i l d and c a p t i v e whales. C a l l r e p e r t o i r e s a r e compared t o the g e o g r a p h i c a l d i s t r i b u t i o n and s o c i a l a s s o c i a t i o n s of pods. F i n a l l y , I d i s c u s s hypotheses t o account f o r the f o r m a t i o n and maintenance of g r o u p - s p e c i f i c c a l l t r a d i t i o n s and d i a l e c t s i n k i l l e r whales. 89 MATERIALS AND METHODS j _ . The Study A n i m a l s The d a t a i n t h i s s tudy r e s u l t p r i m a r i l y from b e h a v i o u r a l o b s e r v a t i o n s and r e c o r d i n g s of v o c a l i z a t i o n s from a p o p u l a t i o n of about 280 k i l l e r whales a l o n g the c o a s t s of B r i t i s h Columbia and Washington S t a t e . The abundance, movements and l i f e h i s t o r y of t h i s p o p u l a t i o n has been s t u d i e d i n t e n s i v e l y s i n c e 1973. ( B i g g et a l . 1976; Balcomb et a l . 1 9 8 0 ; Balcomb et a l . 1982; B i g g 1982). These s t u d i e s were based on o b s e r v a t i o n s of i n d i v i d u a l whales i d e n t i f i e d p h o t o g r a p h i c a l l y by unique n a t u r a l markings on the d o r s a l f i n or l i g h t l y - p i g m e n t e d d o r s a l ' s a d d l e ' . The f o l l o w i n g summary of k i l l e r whale d i s t r i b u t i o n and s o c i a l o r g a n i z a t i o n i s based on t h e s e s t u d i e s and on d a t a c o l l e c t e d d u r i n g t h i s i n v e s t i g a t i o n . The p r i m a r y s o c i a l u n i t of k i l l e r whales i n B r i t i s h Columbia w a t e r s i s the pod, a s t a b l e a s s o c i a t i o n of mixed ages and sexes. Pod members remain t o g e t h e r throughout the y e a r , and have done so over the y e a r s from 1973 t o 1983. Pods g e n e r a l l y c o n t a i n from 5 t o 20 i n d i v i d u a l s , w i t h a range of 1 t o 50. On a v e r a g e , pods are composed of about 1/4 mature males, 1/3 mature f e m a l e s , and the remainder j u v e n i l e s and c a l v e s . Most pods c o n t a i n s e v e r a l females and t h e i r o f f s p r i n g of v a r i o u s ages. These m a t e r n a l a s s o c i a t i o n s u s u a l l y t r a v e l as d i s t i n c t subgroups when the pod i s d i s p e r s e d . Whether d i f f e r e n t b r e e d i n g females i n a pod a r e r e l a t e d i s unknown. There i s c o n s i d e r a b l e e v i d e n c e 90 t h a t young a n i m a l s remain w i t h t h e i r mothers and the pod i n t o m a t u r i t y . No permanent d i s p e r s a l from or exchange between pods has been o b s e r v e d . However, d i f f e r e n t pods or subgroups may t r a v e l t o g e t h e r f o r p e r i o d s of up t o s e v e r a l weeks. Low m o r t a l i t y and b i r t h r a t e s c o n t r i b u t e t o the l o n g - t e r m s t a b i l i t y of the pod. L o n g e v i t y i s e s t i m a t e d t o be 50 y e a r s f o r b u l l s and 75—,100 y e a r s f o r cows. The minimum c a l v i n g i n t e r v a l f o r b r e e d i n g cows i s 3 y e a r s . However, a s u b s t a n t i a l p r o p o r t i o n of females i n the p o p u l a t i o n g i v e b i r t h r a r e l y . Some cows, l i k e l y p o s t - r e p r o d u c t i v e , have not been seen t o g i v e b i r t h s i n c e 1973. Hence, the average c a l v i n g i n t e r v a l i s about 10 y e a r s . A t o t a l of 33 pods occur o f f B r i t i s h Columbia. These pods ar e of two d i s t i n c t t y p e s , " r e s i d e n t " and " t r a n s i e n t " , which d i f f e r i n movements, pod s i z e , b e h a v i o u r and f e e d i n g h a b i t s . R e s i d e n t pods a r e commonly seen i n p r e d i c t a b l e l o c a t i o n s d u r i n g the summer months and a few have been s i g h t e d i n t h e s e same l o c a t i o n s a t o t h e r times of the y e a r , d e s p i t e low o b s e r v e r e f f o r t . T r a n s i e n t pods have l e s s p r e d i c t a b l e movements and a r e seen r e l a t i v e l y i n f r e q u e n t l y . R e s i d e n t pods t y p i c a l l y have 5 o r more members (mean = 13.4, n = 16) w h i l e most t r a n s i e n t pods c o n t a i n 5 or l e s s (mean = 3.2, n = 17). R e s i d e n t pods t r a v e l o n l y w i t h o t h e r r e s i d e n t s and t r a n s i e n t pods w i t h o t h e r t r a n s i e n t s . The two t y p e s of whales do not i n t e r a c t when i n the same a r e a . . W h i l e f o r a g i n g , members of r e s i d e n t pods te n d t o d i s p e r s e w i d e l y and move r a t h e r p r e d i c t a b l y a t c o n s t a n t speeds (see P a r t I ) . T r a n s i e n t pods, i n c o n t r a s t , remain t o g e t h e r and u s u a l l y 91 meander along the shoreline (Part I I I ) . The main diet of resident whales during the summer appears to be f i s h , while transients seem to prey s e l e c t i v e l y on marine mammals. The resident pods are divided into separate "northern" and "southern" communities with d i f f e r e n t d i s t r i b u t i o n s , as shown in Figure 12. Pods from one community are rarely sighted within the range of the other. No pod appears to have an exclusive home range, nor i s there any evidence of mobile t e r r i t o r i a l i t y or group-spacing, such as in wolves (Canis lupus) (Harrington and Mech 1983). Pods frequently associate with others within their community, but no intermixing occurs between the two communities. Table VIII shows the size and composition of resident pods. The alphanumeric designation of Bigg (1982 and pers. comm.) i s used to name pods. Pod names were assigned a r b i t r a r i l y and do not imply degrees of association or relationship. The northern resident community contains 13 pods, t o t a l l i n g about 150 whales. The southern resident commmunity i s comprised of three pods, with a t o t a l of approximately 80 whales. The transient community, consists of 17 pods with about 50 whales. Transient pods travel throughout both resident community ranges. The transient community is discussed in d e t a i l in Part I I I . 92 Figure 12. Map of the known d i s t r i b u t i o n s of the northern and southern communities of resident k i l l e r whale pods, and place names mentioned in the text. Data from M. Bigg (1982 and pers. comm.). T a b l e V I I I . S i z e and c o m p o s i t i o n o f r e s i d e n t pods i d e n t i f i e d o f f Vancouver I s l a n d . Pod s i z e s c o n s i d e r e d e x a c t , e x c e p t those marked by *, which a r e p r o b a b l y a c c u r a t e t o w i t h i n one i n d i v i d u a l . Data from M. B i g g (1982 and p e r s . comm.). Pod S i z e No. o f b u l l s No. o f cows No. Of j u v e n i l e s No. o f of c a l v e s N o r t h e r n R e s i d e n t Community: A l A4 A5 B C D G H I I 14 7 12 8 9 10 19* 6 16* 6 5 19* 4 5 1 1 5 4 4 4 1 4 0 1 3 2 5 2 6 2 2 4 11 3 6 3 2 ? 0 0 1 1 0 0 0 1 0 1 0 0 1 0 111 131 R w S o u t h e r n R e s i d e n t Community: J 19 3 8 K 10 2 5 L 50 9 16 7 3 24 1 0 2 95 2. F i e l d O b s e r v a t i o n s And R e c o r d i n g s Between J u l y , 1978, and October, 1983, I s t u d i e d r e s i d e n t k i l l e r whales a t a v a r i e t y of l o c a t i o n s i n the waters t o the e a s t and s o u t h of Vancouver I s l a n d , B r i t i s h Columbia. Whales were e n c o u n t e r e d on 154 days d u r i n g t h i s p e r i o d , m o s t l y i n June t o September. A l l 16 r e s i d e n t pods known t o oc c u r i n the a r e a were e n c o u n t e r e d and r e c o r d e d a c o u s t i c a l l y . A t o t a l of 426 "pod e n c o u n t e r s " was made w i t h r e s i d e n t s (one pod encounter i s the i n t e r c e p t i o n and i d e n t i f i c a t i o n of one pod on one d a y ) , f o r an average of 2.76 pods per o b s e r v a t i o n day (range = 1-10). The d a t e s , l o c a t i o n s and pods i n v o l v e d i n each encounter a r e summarized i n Appendix I . In a d d i t i o n , I examined 43 r e c o r d i n g s of c a p t i v e and w i l d k i l l e r whales made by o t h e r i n d i v i d u a l s , m o s t l y p r i o r t o the onset of t h i s s t u d y . The e a r l y f i e l d r e c o r d i n g s and t h e i r s o u r c e s a r e l i s t e d i n Appendix I I . Whales were l o c a t e d e i t h e r by p a t r o l l i n g waters known t o be f r e q u e n t e d by pods or w i t h the h e l p of v o l u n t e e r o b s e r v e r s who t e l e p h o n e d when they saw whales. Upon r e c e i p t of a c a l l , i n t e r c e p t i o n of the group was at t e m p t e d . A l l f i e l d work was c a r r i e d out from a 5~m, outboard-powered boat. The i d e n t i f i c a t i o n of the pods p r e s e n t was dete r m i n e d from photographs or v i s u a l l y . About 7500 photographs were t a k e n . Equipment used was a 35 mm s i n g l e - l e n s - r e f l e x camera w i t h a 300 mm l e n s mpunted on a s h o u l d e r b r a c e , and Kodak T r i - X f i l m t a ken at ISO 1200 or 1600. I d e n t i f i c a t i o n s of i n d i v i d u a l whales i n the photographs were made by M.A. B i g g and G. E l l i s ( P a c i f i c 96 B i o l o g i c a l S t a t i o n , Nanaimo, B.C.). A c o u s t i c r e c o r d i n g s were made w i t h a v a r i e t y of equipment, m a i n l y a Nagra I V - S J i n s t r u m e n t a t i o n r e c o r d e r f i t t e d w i t h a s p e c i a l l y - d e s i g n e d p r e a m p l i f i e r / f i l t e r u n i t and a s i n g l e C e l e s c o BC-10 or BC-50 hydrophone. Frequency response of t h i s system v a r i e d w i t h tape speed. Tapes made a t the maximum speed of 38 cm/s (15 i / s ) were f l a t ( + 3 dB) from 100 Hz to 35 kHz. C a s s e t t e r e c o r d e r s (Sony TC-D5M and Superscope C-205) were used e x c l u s i v e l y d u r i n g 1982-83. These systems had f l a t r e s ponses from 100 Hz t o 14 kHz. Some s t e r e o p h o n i c r e c o r d i n g s were made u s i n g a VHF r a d i o - l i n k e d hydrophone deployed from a second boat or from s h o r e , and an o t h e r hydrophone on the r e c o r d i n g boat. 3. Sound a n a l y s i s Most k i l l e r whale s o c i a l s i g n a l s , or c a l l s , can be c l a s s i f i e d by ear i n t o d i s c r e t e c a t e g o r i e s based on d i s t i n c t i v e s t r u c t u r a l c h a r a c t e r i s t i c s . For i n i t i a l c l a s s i f i c a t i o n , sounds were t r a n s c r i b e d u s i n g s y m b o l i c n o t a t i o n s which r e f l e c t the p i t c h and te m p o r a l p a t t e r n i n g of the c a l l s . L a t e r , c l e a r examples from each c a t e g o r y were s e l e c t e d and a n a l y z e d on a Ray 7029A spectrum a n a l y z e r . Most spectrograms were made u s i n g an 80-8000 Hz fr e q u e n c y range w i t h a narrow 45 Hz f i l t e r bandwidth. These a n a l y s e s s e r v e d t o c l a r i f y c a l l c l a s s i f i c a t i o n s , and p e r m i t t e d q u a n t i t a t i v e d e f i n i t i o n and comparisons of c a l l t y p e s . 97 Discrete C a l l C l a s s i f i c a t i o n ; Discrete c a l l s of k i l l e r whales are made up of rapidly emitted pulses which, to the ear, have a tonal qu a l i t y . The repetition rate of these pulses, re f l e c t e d in the harmonic or sideband i n t e r v a l (SBI) seen in spectral analysis, is usually modulated over the c a l l ' s duration. Many c a l l s contain several abrupt s h i f t s in pulse repetition rate, which allow d i v i s i o n of the c a l l into d i f f e r e n t parts. Sound patterns on spectrograms were measured using frequency and duration variables appropriate to the structure of each c a l l type. For simple, one-part c a l l s , the overa l l duration and minimum and maximum sideband intervals were measured. In the more complex c a l l s , duration and SBI measurements were made for each separate part, and other components, such as simultaneous pure tones, were also measured. An average of 8.4 variables (range = 2-17) per c a l l were measured from about 3600 c a l l s . These measurements were made d i g i t a l l y using an Apple Computer Graphics Tablet. Means, ranges, and c o e f f i c i e n t s of variation (c.v. = standard deviation x 100/mean) were calculated for each variable. Comparisons of measurements were carried out using analysis of variance (ANOVA) with 3 a r t l e t t ' s test of homogeneity of variance's and Scheffe's pair-wise comparison of means (Sokal and Rohlf 1981). Discrete c a l l s were c l a s s i f i e d alphanumerically.. Numbers were assigned in the order that c a l l s were i d e n t i f i e d , regardless of which pod was responsible for t h e i r production. C a l l numbers are preceded by a l e t t e r indicating whether they 98 were recorded from northern (N) or southern (S) community residents. Most discrete c a l l types are shared by a number of pods. However, shared c a l l s are often rendered in consistently d i f f e r e n t forms s p e c i f i c to each pod or to groups of pods. Some of these call-type variants are so modified that they were i n i t i a l l y given separate c a l l numbers. Eventually, however,, they were proven to be homologous from subtle structural clues or from patterns of c a l l association. Structurally-unique variants of a discrete c a l l were distinguished by diff e r e n t lower-case Roman numeral suffixes. An example of a t y p i c a l c a l l type i s N9, shared by three pods, A1, A4 and A5, of the northern resident community, but given in a s l i g h t l y d i f f e r e n t manner by each pod. These subtypes are i d e n t i f i e d as N9i, N9ii, and N 9 i i i , respectively. A quantitative measure of s i m i l a r i t y of c a l l repertoires for each pair of pods was obtained by ca l c u l a t i n g an index from the degree of c a l l sharing. This index i s based on Dice's c o e f f i c i e n t of association (see Morgan et a l . 1976), which normalizes the data to account for differences in repertoire s i z e : Index of S i m i l a r i t y = 2(Nc) r1 + r2 where Nc i s the t o t a l number of c a l l types and subtypes shared and r1 and r2 are the repertoire sizes of the pod. These values were then used to calculate a hi e r a r c h i c a l structure of acoustic s i m i l a r i t y , displayed in the form of a 99 dendrogram by means of s i n g l e - l i n k c l u s t e r a n a l y s i s (Morgan e t a l . 1976). P a t t e r n s of C a l l O c c u r r e n c e; To examine the frequency d i s t r i b u t i o n of c a l l types and t h e i r p a t t e r n s of o c c u r r e n c e , c o n t i n u o u s s e c t i o n s of tapes were d i v i d e d i n t o 10-min time p e r i o d s . P r o p o r t i o n s f o r each c a l l type i n each time p e r i o d were c a l c u l a t e d . These were t r a n s f o r m e d u s i n g the a r c s i n e square r o o t , and used as r e p l i c a t e s i n an a n a l y s i s of v a r i a n c e w i t h S c h e f f e ' s t e s t f o r d e t e r m i n i n g the s i g n i f i c a n c e of d i f f e r e n c e s among means. T h i s t e c h n i q u e was chosen over a n a l y s i s of f r e q u e n c i e s s i n c e i t more a c c u r a t e l y r e f l e c t s the v a r i a b i l i t y i n the d a t a . A s s o c i a t i o n s of d i f f e r e n t c a l l t y p e s were examined by c a l c u l a t i n g the p r e c e d i n g and f o l l o w i n g t r a n s i t i o n f r e q u e n c i e s f o r c a l l s w i t h i n each min of the 10-min time p e r i o d s . The t r a n s i t i o n f r e q u e n c i e s f o r each c a l l c o m b i n a t i o n were summed and used t o c a l c u l a t e an index of a s s o c i a t i o n , d e s c r i b e d i n P a r t I . These i n d i c e s were then a r r a n g e d i n a h i e r a r c h y and d i s p l a y e d u s i n g s i n g l e - l i n k c l u s t e r a n a l y s i s . 1 00 RESULTS J _ . R e c o r d i n g and I d e n t i f i c a t i o n of C a l l R e p e r t o i r e s R e c o r d i n g s used t o d e s c r i b e the c a l l r e p e r t o i r e of each pod were made under the f o l l o w i n g c i r c u m s t a n c e s . F i r s t , the pod was re c o r d e d w h i l e t r a v e l l i n g e i t h e r a l o n e or at a s u f f i c i e n t d i s t a n c e from o t h e r groups so t h a t the c a l l s c o u l d be a t t r i b u t e d u n e q u i v o c a l l y t o t h a t pod. Second, the r e c o r d i n g s chosen were made i n s o c i a l and a c t i v i t y c o n t e x t s t h a t were as s i m i l a r as p o s s i b l e , so as t o a v o i d p o t e n t i a l c o m p l i c a t i n g e f f e c t s of c o n t e x t - r e l a t e d v a r i a t i o n i n c a l l use or s t r u c t u r e ( P a r t I ) . F o r a g i n g , the most common a c t i v i t y of r e s i d e n t k i l l e r whales, was s e l e c t e d as the s t a n d a r d c o n t e x t from which samples were drawn. A l l r e c o r d i n g s meeting the above c r i t e r i a were used t o d e s c r i b e the t y p i c a l p a t t e r n of c a l l use f o r the pod. A l s o , r e p r e s e n t a t i v e samples of each c a l l t y p e f o r q u a n t i t a t i v e s t r u c t u r a l a n a l y s i s were drawn from th e s e t a p e s . A l t h o u g h most pods were encountered and r e c o r d e d a l o n e on s e v e r a l o c c a s i o n s , some common groups were seldom found a p a r t from o t h e r whales, and o t h e r pods were s i m p l y r a r e i n the stu d y a r e a . Pod A4, f o r example, was en c o u n t e r e d a t o t a l of 62 t i m e s , but was a l o n e on o n l y 3 of those o c c a s i o n s . In c o n t r a s t , R pod was enc o u n t e r e d on o n l y 3 days, each time i n the presence of 7 or more a d d i t i o n a l pods. D e s p i t e the l i m i t e d samples a v a i l a b l e f o r some groups, i t i s ve r y l i k e l y t h a t most, and i n many cases a l l , c a l l t y p e s i n each pod's r e p e r t o i r e have been i d e n t i f i e d and t h e i r 101 r e l a t i v e frequency of use correc t l y determined. The majority of c a l l s in a pod's repertoire can be heard in one or two 10-min sample periods (Part I ) . Tapes made prior to 1978 are, unless otherwise mentioned, attributed to certa i n pods on the basis of the c a l l types recorded since no photographic evidence of the pods present was available. These early recordings were made in the same locations as those in thi s study. In a l l cases, pods presumed to be present in the older tapes were also recorded recently in the same area. A l l c a l l repertoires present in pre-1978 tapes were also recorded during 1978-83. In the following sections, the discrete c a l l s of resident pods are i l l u s t r a t e d , and their frequency of occurrence in each pod's repertoire is described. Descriptive s t a t i s t i c s of the frequency and duration measurements for each c a l l type, and results of ANOVA's comparing these variables are l i s t e d in Appendix I I I . 2. Dialects of Northern Community Resident Pods. A l l 13 pods in the northern resident community were recorded a c o u s t i c a l l y between 1978 and 1983 off northeastern Vancouver Island. Certain pods share c a l l types yet have no c a l l s in common with other pods in the community. I have termed each d i s t i n c t acoustic association a "clan", defined as a set of pods which shares one or more discrete c a l l types. This term was chosen since i t implies that member pods are part of a common lineage, a notion which, as w i l l be discussed l a t e r , i s not proven but can be considered probable. The northern 102 resident community i s comprised of three clans, the A-clan, G-clan and R-clan. A. A-Clan The A-clan i s comprised of eight pods, A1, A4, A5, B, C, D, H and 11, a l l of which share a portion of their c a l l repertoires. The 19 A-clan c a l l types and the pods observed to produce them are summarized in Table IX. A l l eight pods share a minimum of four c a l l types, N3, N7, N8 and N12. A further three c a l l s , N1, N5 and N11, are produced by a l l but one or two of the groups. The clan i s c l e a r l y divided into two major d i a l e c t groupings on the basis of the remaining c a l l types. The f i r s t , referred to as the "A-group", consists of pods A1, A4 and A5. These pods share four unique c a l l types, N2, N4, N9 and N10, as well as several additional group-specific c a l l types. The second, or "B-group", contains pods B, C, D, H and 11, a l l of which produce c a l l N16. These two groups can be further subdivided according to the c a l l types shared or absent in the repertoires of certain pods, as well as in the d i f f e r e n t renditions of shared c a l l types. I_) C a l l c h a r a c t e r i s t i c s C a l l s shared by most A-clan members: C a l l s given by representatives of both the A- and B-groups of pods include N1, N3, N5, N7, N8, N11 and N12. Most occur in a number of d i f f e r e n t variant forms, or subtypes (Table IX). C a l l N1 is given by a l l A-clan pods with the exception of 103 Table IX. C a l l types and subtypes produced by pods of the A clan in the northern resident community. Pod C a l l A l A4 A5 B C D H 11 i X i i X X NI — i i i i v V X X X X X N2 X X X N3 X X X X X X X X N4 X X X N5 — j i ' i i X X X X X X X X X i X X X N7 — i i i i i i v i X X X X X X X X X X X X X N8 — i i i i i i v i X X X X X X X N9 — 111 X X N10 X X X Nll-I i 1 i i X X X X X X X X N12 X X X X X X X X N13 i X X X N16- i i i i i i v X X X X X N17 X N18 X X N20 X X X X N2i X N27 X N47 X Total 14 14 13 14 9 8 9 13 1 04 A5 pod. There are five d i s t i n c t subtypes of the c a l l , shown in Figure 13. N1 i s a three-part signal which begins t y p i c a l l y with a low-pitch pulse burst having a sideband interval (SBI) of 25-100 Hz (part 1). This short component (average durations 80-220 ms) is followed by part 2, a brief gap (generally < 100 ms) in the pulsed signal during which a narrowband tonal component begins at a frequency of 2500-4500 Hz and increases rapidly to > 8000 Hz for the remainder of the c a l l . The f i n a l portion of the c a l l , part 3, i s the longest, consisting of a pulsed signal which reaches an early peak in pitch, then drops off for the rest of the c a l l . In subtype N1i, given by A1 pod, part 1 i s strongly emphasized and r e l a t i v e l y long in duration compared to other renditions, and part 3 ends with a d i s t i n c t upsweep in p i t c h . Subtype N 1 i i i , shared by pods C and D, i s similar to N l i , except parts 1 and 2 and the terminal upsweep of part 3 are less pronounced. In N1i, part 3 ends at an SBI of > 800 Hz, while in N 1 i i i the upsweep SBI i s < 800 Hz. Subtype N 1 i i i i s given in very similar manner by C and D pods, d i f f e r i n g only in that the peak SBI in part 3 reaches a higher frequency in D's version (p < 0.01). Pod A4 also makes a d i s t i n c t version of c a l l N1 (N1v), distinguished by a consistently high SBI throughout the middle 'plateau', or portion of constant pitch, of part 3 ( > 900 Hz in N1v, < 900 Hz in other subtypes). Subtype N1ii, shared by pods B and 11, d i f f e r s from N1i, N 1 i i i and Nlv in that the c a l l terminates with a s l i g h t downsweep, rather than upsweep, in p i t c h . The renditions of t h i s subtype d i f f e r between B and 11 pod in a number of ways. In the B's 1 05 Figure 13. Spectrograms of A-clan c a l l type N1. The three structural subdivisions, or 'parts' of the c a l l type are marked on bottom of c a l l N1i (A1 pod). In t h i s and other figures showing sample spectrograms of c a l l types, subdivisions are indicated only i f they are referred to in the text. Descriptive s t a t i s t i c s of s tructural variables for a l l c a l l types are given in Appendix I I I . r o T -1 500 ms 107 version, parts 1 and 2 are shorter (p < 0.001 and < 0.01, respectively) and higher in pitch (p < 0.001), while the middle plateau of part 3 is lower and the tonal component higher in frequency (both p < 0.001). Pod H produces the most unique form of c a l l N1, subtype N1iv. Unlike other versions of the c a l l , there i s no portion of constant p i t c h following the early peak in part 3. Instead, the SBI decreases gradually over the remainder of the c a l l , resulting in a very d i s t i n c t i v e sound. Indeed, N1iv i s so unusual that i t s homology with other N1 subtypes would be doubtful were i t not for the diagnostic parts 1 and 2. These, however, are very much reduced in N1iv, and the tonal component is absent in about half of those sampled (12 of 25). In addition to H pod, t h i s subtype i s made rarely by 11 pod. C a l l N3 i s a short, simple three-part c a l l produced by a l l A-clan members. The c a l l occurs in each a c t i v i t y category, but i t is rather uncommon in a l l except low-arousal contexts, when i t predominates (Part I ) . Most of the B-group of pods give an additional c a l l , N20 (described below), during these contexts. An example of c a l l N3 i s shown in Figure 14. Adequate samples of the c a l l could not be obtained for a l l pods, hence group-s p e c i f i c differences could not be i d e n t i f i e d . However, comparisons of frequency and duration for the c a l l as given by pods A l , 'A4 and A5 f a i l e d to detect any s i g n i f i c a n t v a r i a t i o n . C a l l N5 i s used by a l l A-clan pods except C and D. Two subtypes were i d e n t i f i e d , shown in Figure 14. Subtype N5i, produced by a l l pods making the c a l l , i s the simpler of the two. 108 Figure 14. Spectrograms of A-clan c a l l types N3, N5 and N I L * 109 r o i 1 500 ms 1 10 It i s a two-part pulsed signal often with a simultaneous narrowband tonal component. A number of pod-specific differences occur within subtype N5i (Appendix I I I ) . Overall duration, as well as duration of part 1, tend to be longer in the A-pods' versions than B, H and 11's. In many examples of N5i from the A pods and H pod, there i s a peak in SBI early in part 1, after which the SBI quickly drops within 100 ms, then gradually increases once again u n t i l the start of part 2. Part 2 of N5i i s given in a longer form by A5 pod than A1 or A4 (p < 0.01), while H pod produces a longer part B than any other pod (p < 0.001). The SBI of part 1 i s quite uniform among the pods, while part 2 tends to be of a lower pitch in pods B and 11 compared to pods A1, A4, A5 and H (p's < 0.01 or 0.001). F i n a l l y , the tonal component in part 1 i s more prominent in pods B, H and 11 than the A pods, and i t s s t a r t i n g frequency i s s i g n i f i c a n t l y lower (p < 0.001). In summary, pods A1, A4 and A5's renditions of N5i are r e l a t i v e l y similar in most respects, as are those of B, H and 11 pods. The second subtype, N5ii, has two additional components, parts 3 and 4, appended to the end of the N5i versions (Fig. 14). This subtype has been recorded only from pods B, H, and 11, and generally accounts for less than half of the N5 c a l l s emitted by these pods. As in a proportion of H-pod's renditions of N5i, there i s frequently an early peak in SBI at the start of part 1 in N5ii given by t h i s pod. C a l l N7 i s a very common A-clan c a l l type, used by a l l eight pods. There are four d i s t i n c t subtypes of the c a l l , shown 111 i n F i g u r e 15. Subtype N7i i s g i v e n e x c l u s i v e l y by pods A1, A4 and A5. I t c o n s i s t s of two p a r t s ; p a r t 1 i s a low p u l s e - r a t e b u r s t ( g e n e r a l l y < 300 Hz) of 100-250 ms d u r a t i o n , a f t e r which the SBI suddenly i n c r e a s e s , t y p i c a l l y over 50-100 ms, t o about 1300-1400 Hz, which forms p a r t 2. Subtype N 7 i i i s v e r y s i m i l a r , e x c ept a t h i r d component, p a r t 3, f o l l o w s p a r t 2. T h i s p a r t c o n s i s t s of a f u r t h e r upsweep i n SBI, s t a r t i n g a t 1300-1400 Hz and i n c r e a s i n g t o l e v e l s of > 3500 Hz. Pods A1, A4, A5, H and 11 share t h i s s ubtype; a p p r o x i m a t e l y o n e - t h i r d of N7 c a l l s sampled from the A pods were N 7 i i , w h i l e H pod produces t h i s v a r i a n t e x c l u s i v e l y . Pod 11 uses both N 7 i i and the t h i r d s u b t y p e , N 7 i i i . T h i s l a t t e r s u b t y p e, g i v e n o n l y by B and 11 pods, i s s i m i l a r t o the t h r e e - p a r t N 7 i i , but p a r t 2 has a much lower p i t c h . The SBI i n t h i s component of N 7 i i i i s < 800 Hz, w h i l e i n N 7 i i and N 7 i v ( d e s c r i b e d n e x t ) , the SBI i s > 1100 Hz. The f i n a l s u b t y p e, N 7 i v , i s g i v e n e x c l u s i v e l y by pods C and D. T h i s t h r e e - p a r t s i g n a l has an SBI i n p a r t 2 which i s comparable t o N 7 i i , but p a r t 3 b e g i n s a t an SBI g e n e r a l l y > 1000 Hz h i g h e r i n f r e q u e n c y . In a d d i t i o n , the v a r i a n t d i f f e r s from o t h e r N7 subtypes i n t h a t p a r t 1 i s v e r y much reduced i n i n t e n s i t y r e l a t i v e t o o t h e r p a r t s of the c a l l . W i t h i n each N7 s u b t y p e , t h e r e a r e a number of p o d - s p e c i f i c d i f f e r e n c e s i n c a l l s t r u c t u r e , l i s t e d i n Appendix I I I . As d e s c r i b e d i n P a r t I , the o c c u r r e n c e of c a l l N8 i s c l o s e l y t i e d t o N7. N8's a r e produced by a l l A - c l a n pods, and i n each case the c a l l i s never g i v e n w i t h o u t f i r s t b e i n g preceded 1 t o 4 s e a r l i e r by an N7. Four subtypes of the c a l l 1 12 Figure 15. Spectrograms of A-clan c a l l types N7 and 113 I • 1 0 500 ms 1 1 4 were i d e n t i f i e d ( F i g . 15). Subtypes N 8 i , N 8 i i and N 8 i i i share a s i m i l a r two-part format; p a r t 1 c o n s i s t s of a p u l s e d component w i t h a low r e p e t i t i o n r a t e of < 50 Hz, w h i l e p a r t 2 has h i g h e r p u l s i n g r a t e s of up to 900 Hz. Subtype N 8 i , e m i t t e d by pods A1, A4, A5 and H, has a r a p i d i n c r e a s e then g r a d u a l d e c r e a s e of p u l s e r a t e i n p a r t 2. In H-pod's v e r s i o n , p a r t 1 i s b r i e f compared t o t h a t of the A pods', w h i l e p a r t 2 i s l o n g e r (both p < 0.001). A l s o , the SBI i n p a r t 2 s t a r t s and peaks a t h i g h e r f r e q u e n c i e s i n pod H than the A pods (p < 0.001). A v a r i e t y of d i f f e r e n c e s i n the s t r u c t u r e of N8i a l s o occur w i t h i n the A pods. P a r t 2 of the c a l l t ends t o be l o n g e r i n A5's v e r s i o n s (p < 0.001), w h i l e the peak SBI of the same component i s lower i n A1 than A4 or A5 (p < 0.001). Subtype N 8 i i i s , t o the e a r , q u i t e d i f f e r e n t from o t h e r N8 v a r i a n t s and was o n l y d e t e r m i n e d t o belong t o the c a l l type from i t s a s s o c i a t i o n w i t h c a l l N7. P a r t 2 of the subtype has a p i t c h t h a t , r a t h e r than i n c r e a s i n g and d e c r e a s i n g as i n o t h e r v a r i a n t s , i s h e l d r e l a t i v e l y c o n s t a n t a t SBI's of 200-300 Hz. N 8 i i i s g i v e n e x c l u s i v e l y by pods C and D, and the o n l y pod-s p e c i f i c d i f f e r e n c e e v i d e n t i s i n the t e r m i n a l SBI of p a r t 2, which i s s i g n i f i c a n t l y h i g h e r i n D pod (p < 0.001). Subtypes N 8 i i i and N8iv a r e both produced o n l y by pods B and 11. N 8 i i i i s s i m i l a r t o N 8 i , except t h a t f o l l o w i n g the SBI peak, the SBI d e c r e a s e s somewhat then i s h e l d a t a r e l a t i v e l y h i g h 450-700 Hz f o r the remainder of the c a l l . I n N 8 i , the SBI c o n t i n u e s t o d e c l i n e t o l e v e l s of 100-400 Hz a t the end of the c a l l . N 8 i v d i f f e r s from o t h e r v a r i a n t s i n t h a t the SBI i n p a r t 1 15 2 drops sharply following the peak, and then i s maintained at low rates of < 50 Hz u n t i l the end of the c a l l . This terminal component (part 3) averages about 115 ms in duration. C a l l N11 i s an unusual and, in most contexts, uncommon signal recorded from a l l pods of the A-clan except 11 - i t s absence in t h i s pod may be a result of the short recording samples ava i l a b l e . Two subtypes occur, both i l l u s t r a t e d in Figure 14. N11i begins with an 80-200 ms component with an SBI of about 1500 Hz, followed by part 2, a longer noisy pulse-burst of 500 ms to almost 2.0 s duration in some samples. Part 3, terminating the c a l l , is similar in structure to part 1. Subtype N11i i d i f f e r s from N11i in part 2, which i s broken up into a number of short (about 30-120 ms) bursts separated by gaps t y p i c a l l y of 60 to 100 ms duration. Pods A1, A4 and A5 produce subtype N11i exclusively, while B pod makes both N11i and N 1 l i i . Pods C, D and H, appear to use N11ii only. C a l l N12 i s another infrequently used c a l l that i s shared by a l l A-clan pods. Although no discrete subtypes are apparent in the three-part signal, much group-related v a r i a t i o n occurs. As i l l u s t r a t e d in Figure 16, the most pronounced differences are in the terminal upsweep of the c a l l , or part 3. This component in the A pods reaches mean SBI's of < 700 Hz, while pods B, C, D, H and 11 have mean SBI's of > 1000 Hz. Within the A pods, A5 has a higher upsweep than either A1 or A4 (p < 0.01). There are no s i g n i f i c a n t differences in t h i s component within the B-group of pods, and a l l are s i g n i f i c a n t l y greater than the A-pods, with the exception of 11 compared to A5. Numerous less marked 1 1 6 Figure 16. Spectrograms and structural measurements of A-clan c a l l type N12. A = Examples of t y p i c a l renditions of N12 by pods A1 and C. B = D i s t r i b u t i o n of average sideband intervals (with 95% confidence intervals) at the termination of N12 c a l l s sampled from A-clan pods. 117 I 1 1 0 500 ms B. 2000 i ui 1000 -A1 A4 A5 B C D H 11 POD 1 18 d i f f e r e n c e s i n o t h e r v a r i a b l e s are l i s t e d i n Appendix I I I . C a l l s Used by the A-Group of Pods Only: Pods A1, A4 and A5 share f o u r c a l l t y p e s , N2, N4, N9 and N10, which are g i v e n by no o t h e r pods. In a d d i t i o n , A4 and A5 pods share c a l l N13, c a l l s N27 and N47 a r e g i v e n by A1 a l o n e , and N17 and N19 a r e used s o l e l y by A5 and A4, r e s p e c t i v e l y . C a l l N2 i s one of the more common c a l l s of the A-pods. I t i s a t h r e e - p a r t c a l l w i t h an e x t r e m e l y d i s t i n c t i v e s t r u c t u r e and sound ( F i g . 17). P a r t 1 i s a s h o r t (means = 55-75 ms) p u l s e b u r s t w i t h SBI's of about 300-600 Hz. P a r t 2, the l o n g e s t component, undergoes a smooth up-down-up p i t c h m o d u l a t i o n a t h i g h e r SBI's of 1000 t o 2500 Hz. The c a l l ends w i t h p a r t 3, a s harp upsweep u s u a l l y < 100 ms i n d u r a t i o n . In a d d i t i o n t o these t h r e e p a r t s , N2's have a d i s t i n c t narrowband t o n a l component which b e g i n s a t the s t a r t of the c a l l at f r e q u e n c i e s of 4800-7600 Hz, then r i s e s q u i c k l y t o 7400-8100 Hz, where i t i s h e l d c o n s t a n t f o r the r e s t of the c a l l . P o d - s p e c i f i c d i f f e r e n c e s i n c a l l N2 o c c u r m a i n l y i n p a r t s 2 and 3. Pod-A1's v e r s i o n s of the c a l l u s u a l l y a r e l a c k i n g p a r t 3 ( i n 24 of 31 samples, or 77.4 % ) , and when the component i s p r e s e n t i t i s s i g n i f i c a n t l y reduced (maximum frequency r e a c h e d by the second s i d e b a n d i s l e s s than i n A4 (p < 0.01) and A5 (p < 0.001)). Pods A4 and A5 t e n d t o produce h i g h e r p i t c h e d N2's,, r e f l e c t e d i n the o v e r a l l g r e a t e r SBI's i n p a r t 2 (e.g. SBI, end of p a r t 2: A4 and A5 > A1, p < 0.001) and the h i g h e r f r e q u e n c i e s i n p a r t 3. In a d d i t i o n , the time i n t e r v a l between the s t a r t of p a r t 2 and the SBI peak i n the f i r s t p i t c h i n f l e c t i o n i s 1 19 Figure 17. Spectrograms of A-clan c a l l types N2, N4 and 120 121 c o n s i s t e n t l y s h o r t e r i n A1's r e n d i t i o n s compared t o A4's, which i n t u r n a r e s h o r t e r than A5's ( a l l p < 0.001). C a l l N4 i s c o n s i s t e n t l y the most common c a l l i n the r e p e r t o i r e s of pods A1, A4 and A5. I t i s a r e l a t i v e l y s i m p l e t wo-part s i g n a l ; p a r t 1 i s the l o n g e r , c o n s i s t i n g of a p u l s e d component which r i s e s r a p i d l y i n p i t c h t o an e a r l y peak, then g r a d u a l l y d e c l i n e s and l e v e l s o f f u n t i l p a r t 2, a s h o r t (means = 35-65 ms) l o w e r - p i t c h e d component ( F i g . 17). One major d i f f e r e n c e i n s t r u c t u r e of the c a l l as g i v e n by the t h r e e pods i s i n the o c c u r r e n c e of a s l i g h t upsweep i n SBI a t the end of p a r t 1, which o c c u r s i n the m a j o r i t y of samples from A4 and A5 (76.9% and 59.5%, r e s p e c t i v e l y ) but i n o n l y 17.9% from A1 pod. In a d d i t i o n , p a r t 2 i s absent i n 66.7% of samples from A1 pod, compared t o 5.7% i n A4 and 4.7% i n A5. When p a r t 2 i s p r e s e n t i n A1-pod's N4 c a l l s , i t i s of a s i g n i f i c a n t l y s h o r t e r d u r a t i o n (p < 0.001) than the c o u n t e r p a r t s from A4 and A5 pods. One f i n a l d i f f e r e n c e i s i n the peak SBI reached i n p a r t 1, which i s h i g h e r i n pod A4 than e i t h e r A1 or A5 (p < 0.001 and 0.05, r e s p e c t i v e l y ) . C a l l N9 i s another v e r y common s i g n a l of the A-pods. Each pod uses a s i m i l a r f o u r - p a r t c a l l f o r m a t , but the p o d - s p e c i f i c d i f f e r e n c e s a r e so d i s t i n c t t h a t the c a l l can be d i v i d e d i n t o t h r e e d i s c r e t e subtypes ( F i g . 17). Most d i f f e r e n c e s occur i n the t h i r d p a r t of the c a l l . T h i s component s t a r t s w i t h SBI's of 1100-1900 Hz which, i n subtypes N 9i and N 9 i i i (pods A1 and A5, r e s p e c t i v e l y ) , c l i m b s t e a d i l y t o peaks of 1400-2100 Hz a t the s t a r t of p a r t 4. In A4 pod's v e r s i o n (subtype N 9 i i ) , the SBI 1 22 reaches h i g h e r peak f r e q u e n c i e s (mean = 3058 Hz; p < 0.001), then drops s h a r p l y i n the f i n a l 46 ms (range = 13-77 ms) b e f o r e the s t a r t of p a r t 4. A1-pod's subtype N 9 i , has a very s h o r t p a r t 4, c o n s i s t i n g of an upsweep a v e r a g i n g 900 Hz (measured on the second sideband) i n < 55 ms. In c o n t r a s t , p a r t 4 i n A4 and A5 pod's r e n d i t i o n s c o n s i s t of a pronounced downsweep i n p i t c h , w i t h average d u r a t i o n s of 94 and 108 ms, r e s p e c t i v e l y . T h i s component i s s i g n i f i c a n t l y l o n g e r and h i g h e r i n frequency i n A5 pod compared t o A4 (b o t h p < 0.01). N10, a f a i r l y uncommon f o u r - p a r t c a l l , i s shared by a l l t h r e e A-pods. I t has a v e r y s i m i l a r s t r u c t u r e t o N 1 i , g i v e n by A1 pod, ex c e p t t h a t the l o n g p l a t e a u of c o n s t a n t p i t c h i n p a r t 3 of N1i i s absent i n N10 ( F i g . 18). No subtypes of N10 were i d e n t i f i e d , and few g r o u p - s p e c i f i c d i f f e r e n c e s were a p p a r e n t . The most i m p o r t a n t of thes e i s t h a t p a r t 4 of A5's v e r s i o n of the c a l l i s s i g n i f i c a n t l y l o n g e r than both A1's (p < 0.01) and A4's (p < 0.05). The r e m a i n i n g f i v e c a l l s from the c o l l e c t i v e A-pod r e p e r t o i r e a r e e m i t t e d by o n l y one or two of the t h r e e groups, and a l l a r e c o m p a r a t i v e l y uncommon. R e p r e s e n t a t i v e spectrograms of these s i g n a l s a re shown i n F i g u r e 18. C a l l s N13, shared by A4 and A5 pods, N17, produced by A5, and N27 and N47, g i v e n o n l y by A1, a r e r e l a t e d i n s t r u c t u r e t o N1, N9, and N10. A l l these c a l l s b e g i n w i t h a s i m i l a r low p u l s e - r a t e b u r s t , f o l l o w e d by a d d i t i o n a l h i g h e r f r e q u e n c y components and a s i m u l t a n e o u s narrowband tone which b e g i n s a t a fr e q u e n c y of 3 0 0 0 - 5 0 0 0 Hz a t the end of p a r t 1, then i n c r e a s e s t o > 8000 Hz. Major 1 23 Figure 18. Spectrograms of A-clan c a l l types N10, N13, N17 N19, N27 and N47. 124 125 d i f f e r e n c e s d i s t i n g u i s h i n g the c a l l t ypes o c c u r i n the s t r u c t u r e of p a r t s 2, 3 or 4, where t h e s e p a r t s a re p r e s e n t . N47 appears t o be c l o s e l y r e l a t e d t o N9, d i f f e r i n g o n l y i n t h a t N47 has a number of m o d u l a t i o n s i n p u l s e r a t e i n the e q u i v a l e n t of p a r t 2 of N9. C a l l N19 was r e c o r d e d o n l y from A4 pod, and i s s i m i l a r t o N4. I t d i f f e r s from the l a t t e r i n t h a t t h e r e i s a s i g n i f i c a n t peak i n p i t c h towards the end of c a l l , f o l l o w e d by ano t h e r d i p , and the t e r m i n a l component ( p a r t 2) of N4 i s l a c k i n g . C a l l s Used by the B-Group of Pods Only: The B-group of pods, c o m p r i s e d of pods B, C, D, H, and I I , has a t o t a l of fo u r c a l l t y p e s , N16, N18, N20 and N21, which a r e not used by any o t h e r pods. Of t h e s e , N16 i s the o n l y c a l l s h a r e d by a l l f i v e pods, and i t tends t o be an im p o r t a n t component i n most r e p e r t o i r e s . T h i s d i s t i n c t i v e s i g n a l o c c u r s i n f o u r v a r i a n t forms, i l l u s t r a t e d i n F i g u r e 19. A l l share a common f o u r - p a r t f o r m a t ; p a r t 1, the l o n g e s t component, i s a g r a d u a l l y r i s i n g tone w i t h SBI's s t a r t i n g a t about 1000 Hz and ending a t 1500-2000 Hz. P a r t 2, a s h o r t l o w e r - p i t c h e d p u l s e b u r s t at SBI's of t y p i c a l l y < 1000 Hz, i s f o l l o w e d by a sudden s h i f t i n SBI t o about 2500-3000 Hz. T h i s i n c r e a s e s t o > 6000 Hz i n many c a s e s , then drops t o 2500-4000 Hz, e n d i n g p a r t 3. The t e r m i n a l p a r t 4 i s a n o t h e r s h o r t component v e r y s i m i l a r t o p a r t 2. In a d d i t i o n t o t h e s e f o u r p u l s e d components, t h e r e i s a s i m u l t a n e o u s narrowband tone which b e g i n s a t about 2000-3000 Hz a t the s t a r t of the c a l l , then i n c r e a s e s q u i c k l y t o > 8000 Hz. The most i m p o r t a n t d i s t i n g u i s h i n g f e a t u r e s of N16 subtypes 1 26 Figure 19. Spectrograms of A-clan c a l l types N16, N18. N20 and N21. 127 r o 1 1 500 ms 1.28 are as follows: N16i, emitted only by pod B, has a comparatively short part 2 (mean = 43 ms) with a noisy structure. Sidebands can be resolved in only 35.7% (10 of 28) of the sample spectrograms. Part 4 i s also reduced, with a mean duration of 27 ms (range = 17-35 ms). In contrast, N16ii, made by C and D pods, has a longer part 2 (means = 63 and 68 ms, respectively) with d i s t i n c t sideband structure. Part 4 of the subtype i s si m i l a r l y well developed, having mean durations of 61 ms (C pod) and 65 ms (D pod), more than double the mean duration of the same component in B's version. A gap of about 40-140 ms between the end of part 1 and the start of part 2 i s evident in some 40 to 50% of N16ii's. This does not occur in any other N1<6 variants. The only difference apparent in C and D's production of N16ii i s that the peak frequency reached in part 3 i s s i g n i f i c a n t l y higher in D pod (p < 0.01). N 1 6 i i i , a subtype shared by H and 11 pods (used only rarely in the l a t t e r ) , has a well-defined part 2 (mean duration in pod H = 111 ms), but parts 3 and 4 are very much reduced. Although part 3 l a s t s an average of 430 ms in pod H's versions, the high pitch component ends after a mean of 173 ms, leaving the remaining 60% (on average) of the part with no sound. Part 4 i s of a low r e l a t i v e intensity and brief duration (mean = 22 ms in H pod). Subtype Nl6iv, produced only by 11 pod, closely resembles N16i i i in most respects except that part 2 i s en t i r e l y absent. Instead, the SBI continues to increase steadily from part 1 into part 3. Three of the four N16 variants, N l 6 i i , N16iii and N!6iv, also occur in abbreviated forms which lack the 1 29 descending p i t c h - p o r t i o n of p a r t 3 and a l l of p a r t 4. Of the t h r e e r e m a i n i n g B-group c a l l s , N20 i s the o n l y s i g n a l g i v e n by a l l the pods, w i t h the apparent e x c e p t i o n of H pod. L i k e c a l l N3, N20's are heard p r e d o m i n a t e l y d u r i n g low-a r o u s a l or r e s t i n g c o n t e x t s , a l t h o u g h they are r e c o r d e d i n f r e q u e n t l y d u r i n g a l l major a c t i v i t i e s . I t i s a s i m p l e one-p a r t c a l l c o n s i s t i n g of a p u l s e d tone which i n c r e a s e s i n p i t c h t o a peak near the middl e of the c a l l , then r e t u r n s t o the o r i g i n a l p i t c h a t the c a l l ' s end ( F i g . 19). N20's g i v e n by pods C and D r e a c h SBI peaks a v e r a g i n g 781 and 928 Hz, r e s p e c t i v e l y , s i g n i f i c a n t l y h i g h e r than the 464 Hz rea c h e d on average by B pod's v e r s i o n s (p < 0.001). Only two samples a r e a v a i l a b l e f o r N20's produced by 11 pod, but they have a mean peak SBI of 484 Hz, s i m i l a r t o B pod. C a l l s N18 and N21 a r e r e l a t i v e l y uncommon s i g n a l s r e c o r d e d from B and C pods, and B pod a l o n e , r e s p e c t i v e l y ( F i g . 19). I I ) C a l l use The A-Group of P o d s t The fr e q u e n c y of o c c u r r e n c e of d i s c r e t e c a l l t y p e s i n the r e p e r t o i r e s of pods A1, A4 and A5 d u r i n g v a r i o u s a c t i v i t y c o n t e x t s , and t h e i r p a t t e r n of use from t r a n s i t i o n a n a l y s e s , a r e d e s c r i b e d i n P a r t I . A number of e a r l y (pre-1978) r e c o r d i n g s of c a l l s made a p p a r e n t l y by the A-pods were o b t a i n e d and a n a l y z e d (Appendix I I ) . The frequ e n c y d i s t r i b u t i o n s of c a l l t y p e s r e c o r d e d i n the s e e n c o u n t e r s , as w e l l as those i d e n t i f i e d from r e c o r d i n g s made of A1, A4 and A5 pods w h i l e f o r a g i n g t o g e t h e r d u r i n g 1978 t o 1981, are shown i n 1 30 F i g u r e 20. There i s c o n s i d e r a b l e c o n s i s t e n c y i n c a l l use from year t o y e a r . A n a l y s e s of v a r i a n c e w i t h p a i r - w i s e comparisons f o r c a l l s N1 through N12 among the samples f o r 1964, 1973, 1978, 1979, 1980 and 1981 r e v e a l e d few s i g n i f i c a n t d i f f e r e n c e s . These c o n s i s t e d of a reduced o c c u r r e n c e of c a l l N9 i n 1964 compared t o 1978 and 1979 (both p < 0.01), and the same comparing N9 i n 1981 to 1978 and 1979 (both p < 0.05). The A-pod c a l l s N13, NT7, N19, N27, and N47 were r e c o r d e d too i n f r e q u e n t l y t o warrant s t a t i s t i c a l c omparison; however, a l l a r e r e p r e s e n t e d i n r e c o r d i n g s made as e a r l y as 1973. These c a l l s may w e l l have been used p r i o r t o t h a t date but s i m p l y d i d not occur i n the s m a l l samples a v a i l a b l e . There i s s i g n i f i c a n t v a r i a t i o n i n the f r e q u e n c y of use of shared c a l l s by the t h r e e A-pods ( F i g . 2 1 ) . Pod A4 tends t o produce N4 and N12 c a l l s p r o p o r t i o n a t e l y more o f t e n than do A1 and A5, and c a l l s N5 and N9 l e s s o f t e n . C a l l N10 o c c u r s more f r e q u e n t l y i n the r e p e r t o i r e of A5 pod than A1 or A4, and A1 uses c a l l N1 more o f t e n than A4 pod. No d i f f e r e n c e s were e v i d e n t i n the o c c u r r e n c e of c a l l s N2, N3, N7, N8 and N11. The f r e q u e n c y d i s t r i b u t i o n s of c a l l t y p e s r e c o r d e d d u r i n g e n c o u n t e r s w i t h A1 pod a l o n e a r e shown i n F i g u r e 22. The p r e -1978 d i s t r i b u t i o n i s based on two s h o r t e n c o u n t e r s combined. The f i r s t , made by P. Spong i n the Johnstone S t r a i t a r e a on August 19, 1971, was r e c o r d e d i n the presence of a group c o n t a i n i n g a w e l l - m a r k e d a n i m a l d e t e r m i n e d l a t e r t o b e l o n g t o A1 pod ( B i g g et a l . 1976). The second was r e c o r d e d by E. Hoyt i n Johnstone S t r a i t on August 26, 1973; photographs taken by 131 Figure 20. Frequency d i s t r i b u t i o n s of c a l l s produced by pods A1, A4 and A5 while foraging together. Pre-1978 samples are assumed to have involved the A-pods on the basis of c a l l types recorded. 132 30 20 10 H 0 20 10 H 0 30 H 20 10 >-o 0-EN 30-Z) o 20-LU CC 10-LL I- 0-1 z — LU o 20-rx LU 10-CL 20-10-0 30-20-10-0 1964 n= 375 calls 1970 n= 293 calls 1973 n= 1622 calls 1978 n= 832 calls 1979 n= 3870 calls i i 1980 n= 2295 calls 1981 n= 4793 calls N1 N2 N3 N4 N5 N7 N8 N9 N10 N11 N12 N13 N17 N19 N27 N47 CALL TYPE 1 33 Figure 21. Frequency d i s t r i b u t i o n s of c a l l s produced by pods A1, A4 and A5, during 1978-83 combined. 134 30 -| 20 ->- 10 -o z UJ 0-ID o 40 -LU CC LL 30 -y- 20 -z LU 10 -O DC o J LU CL 30 -20 -10 -o -I A1 Pod n= 2866 calls A4 Pod n= 681 calls A5 Pod n= 2443 calls 3= N1 N2 N3 N4 N5 N7 N8 N9 N10 N11 N12 N13 N17 N19 N27 N47 CALL TYPE 1 35 Figure 22. Frequency d i s t r i b u t i o n s of c a l l s produced by A1 pod alone, 1971-1983. Recordings from 1971 and 1973 are known to have involved A1 pod from v i s u a l or photographic evidence. 40-, 3 0 -2 0 -10-o-3 0 -2 0 -10-1971 &1973 n= 172 calls 1978 n= 1031 calls 20 -10-1979 n= 932 calls 3 0 -2 0 -10-0 - -1981 n= 310 calls 2 0 -10-0-1983 n= 454 calls N1 N2 N3 N4 N5 N7 N8 N9 N10 N11 N12 N27 N47 CALL TYPE 1 37 M. Bigg and co-workers at thi s location on the same day contain A1 whales exclusively (M. Bigg, pers. comm.). C a l l types and variants recorded on both occasions are t y p i c a l of A1 pod. Comparing the frequency of use for c a l l s N1 to N12 and N47 in these early encounters and in A1 recordings made during 1978, 1979, 1981, and 1983 revealed no s i g n i f i c a n t differences. The uncommon c a l l N27 was recorded in the recent samples but not in 1971-73. The B-Group of Pods: The five B-group pods can be divided into two subgroups based on c a l l use; the f i r s t contains B, H and II which share c a l l N5 and some subtypes of other c a l l s , and the second contains C and D pods, which do not give N5 and share subtypes of other c a l l s . The frequency d i s t r i b u t i o n of B-pod c a l l s during 1971 and 1973 combined, 1980 and 1981 are shown in Figure 23. The 1973 recording, made by E. Hoyt in Johnstone S t r a i t on August 24, 1973, contained c a l l s c h a r a c t e r i s t i c of both the A-pods and B. I d e n t i f i c a t i o n photos taken independently at the same time and location by M. Bigg (pers. comm.) confirm that pods A1, A4, A5 and B were present in the area. A l l but the uncommon c a l l N11 are present in the 1971/73 sample, and ANOVA comparisons of c a l l occurrence among this early sample and those from 1980 and 1981 revealed no s i g n i f i c a n t differences. Contingency table analysis of a preceding/following t r a n s i t i o n matrix for a l l c a l l s in B-pod's repertoire except N3 and N21 indicate that c a l l occurrence was highly non-random (G = 850.5, df = 49, p < 0.001). Cluster analysis of association indices calculated from th i s matrix 138 Figure 23. Frequency d i s t r i b u t i o n s of c a l l s produced by B pod. Tapes from 1971-73 are assumbed to have involved B pod on the basis of c a l l types recorded. 40-1 30-20-10-5 o-UJ 2 3 ° -DC 20-tu o DC LU CL 10-o-20-10-o-1971-1973 n= 187 calls 1980 n= 937 calls 1981 n= 774 calls N1 N3 N5 N7 N8 N11 N12 N16 N18 N20 N21 CALL TYPE 140 (F i g u r e 24) i l l u s t r a t e the v e r y c l o s e a s s o c i a t i o n of c a l l s N7 and N8, as d e s c r i b e d f o r the A-pods ( P a r t I ) . Other than t h i s p a i r , no c a l l s show s t r o n g t e n d e n c i e s t o occur t o g e t h e r . The d i s t r i b u t i o n s of c a l l s produced by pods H and 11 a r e i l l u s t r a t e d i n F i g u r e 25. C a l l s c h a r a c t e r i s t i c of H pod were p r e s e n t i n two s h o r t samples from 1970 and 1974. A l t h o u g h too few samples a r e a v a i l a b l e f o r s t a t i s t i c a l c o mparison, the p a t t e r n of c a l l use seems q u i t e s i m i l a r between these e a r l y tapes and t h o s e made d u r i n g 1978-82. C a l l s N3 and N11, however, were not p r e s e n t i n the o l d e r r e c o r d i n g s . Pod I 1 ' s r e p e r t o i r e was not e v i d e n t i n any pre-1978 t a p e . Comparisons of f r e q u e n c y of o c c u r r e n c e of c a l l N5 r e v e a l e d no s i g n i f i c a n t v a r i a t i o n between pods B, H and 11, but a l l t h r e e groups produce the c a l l more o f t e n than the A-pods (p < 0.001). B pod produces N1 l e s s o f t e n than H pod (p < 0.05); n e i t h e r pod d i f f e r s from 11 pod i n use of N1, but a l l produce the c a l l more f r e q u e n t l y than the A-pods. O c c u r r e n c e of N7 i s s i m i l a r i n B, H, 11 and the A-pods, but N8 i s used l e s s o f t e n by the A's (p < 0.001). The c o n s i d e r a b l e s i m i l a r i t y i n the s t r u c t u r e of c a l l s produced by pods C and D i s p a r a l l e l e d , i n most c a s e s , i n t h e i r use of those c a l l s ( F i g . 2 6 ) . The p r i n c i p a l d i f f e r e n c e l i e s i n the p r o d u c t i o n of the s h o r t and l o n g v e r s i o n s of N16; i n D pod, the s h o r t form r e p r e s e n t s 39.5% of t o t a l c a l l use, s i g n i f i c a n t l y g r e a t e r (p < 0.00-1) than the 12.9% i n C pod. C pod's use of the l o n g form amounts t o 28.2% of a l l c a l l s , i n c o n t r a s t t o 3.9% i n D pod (p < 0.001). The o n l y o t h e r s i g n i f i c a n t v a r i a t i o n between samples of t h e two r e p e r t o i r e s was i n N20, which o c c u r r e d more 141 Figure 24. Cluster diagram of c a l l associations in the repertoire of B pod.. Associations are based on an index derived from t r a n s i t i o n frequencies between c a l l types. See text for further d e t a i l s . 0.0 0.1 Q Q2 0.3 0.4 0.5 -B Pod 0.6 L N7 N8 N1 N5 N16 N18 N20 CALL TYPE 1 4 3 Figure 25. Frequency d i s t r i b u t i o n s of c a l l s produced by pods H and 11. Tapes from 1970 and 1974 are assumed to have involved H pod on the basis of c a l l types recorded. 144 O z LU ZD o LU cr LU o cc LU CL 30-, 20-10-0-3 0 - " 2 0 -10-0-2 0 -10-0-H Pod 1970 n= 31 calls 1974 n= 57 calls 1978-1982 n= 751 calls N1 N3 N5 N7 N8 N11 N12 N16 CALL TYPE 5 Z 30-LU ZD o LU DC LU O DC LU CL 20' 10 H 0-11 Pod 1979-1980 n= 388 calls N1 N3 N5 N7 N8 N12 N16 N16 N20 short CALL TYPE 1 45 F i g u r e 26. Frequency d i s t r i b u t i o n s of c a l l s produced by C and D pods, and the c a p t i v e whale "Namu". "Namu" was i d e n t i f i e d by M. B i g g ( p e r s . comm.) as h a v i n g been t a k e n from C pod i n June, 1965. Tapes from 1964 adn 1973 are assumed t o have i n v o l v e d C and/or D pods on the b a s i s of c a l l t y p e s r e c o r d e d . 50-, 40 30 20 10 C Pod (?) 1964 n= 562 calls 30-20-10-Namu 1965 n= 511 calls 20 10-1 C / D Pods 1973 n= 315 calls 1 20-10-0-40-30-| 20 10 H C Pod 1978-1980 n= 372 calls 0 D Pod 1978-1980 n= 1342 calls 1 N1 N3 N7 N8 N11 N12 N16 N16 N18 N20 short CALL TYPE 147 o f t e n i n the D pod r e c o r d i n g s (p < 0.01). There i s a good d e a l of e v i d e n c e t o suggest t h a t the r e p e r t o i r e of C pod has changed l i t t l e s i n c e 1964. R e c o r d i n g s made a p p a r e n t l y i n the presence of the group i n t h a t year c o n t a i n a l l but one (N3) of the c a l l s used i n r e c e n t y e a r s , and t h e i r f r e q u e n c y of o c c u r r e n c e d i f f e r s o n l y i n the s h o r t form of c a l l N16, which was s i g n i f i c a n t l y (p < 0.05) l e s s common i n 1964. Another i n d i c a t i o n of r e p e r t o i r e s t a b i l i t y i n the pod r e s u l t s from r e c o r d i n g s of the whale "Namu", which was c a p t u r e d i n 1965 from a group determined l a t e r by M. B i g g t o be C pod. T h i s a n i m a l produced a l l c a l l s t y p i c a l of the pod except the uncommon N18 and N20, and the f r e q u e n c y d i s t r i b u t i o n of those c a l l s d i f f e r s o n l y i n the s h o r t form of N16, which a g a i n was l e s s o f t e n used (p < 0.001). C l u s t e r a n a l y s e s of the t r a n s i t i o n a s s o c i a t i o n s of common c a l l s of C pod and Namu show a s i m i l a r p a t t e r n of c a l l use ( F i g . 2 7 ) . There a re s i g n i f i c a n t d i f f e r e n c e s i n some s t r u c t u r a l v a r i a b l e s of Namu's c a l l s compared t o C-pod's c a l l s r e c o r d e d d u r i n g 1978-80 (Appendix I I I ) , but the o v e r a l l forms of the s i g n a l s a r e f u n d a m e n t a l l y the same. Sample spectrograms of two C-pod c a l l s as they o c c u r r e d i n 1964, from Namu, and d u r i n g 1978-80 a r e shown i n F i g u r e 28. I l l ) Summary of a c o u s t i c a s s o c i a t i o n s ; A - c l a n An a p p r a i s a l of a c o u s t i c a s s o c i a t i o n s w i t h i n the A - c l a n was o b t a i n e d u s i n g an index of r e p e r t o i r e s i m i l a r i t y f o r each p a i r of pods (Table X ) , and a r r a n g i n g t h e s e v a l u e s i n t o a dendrogram by means of s i n g l e - l i n k c l u s t e r a n a l y s i s ( F i g u r e 2 9 ) . The 1 48 Figure 27. Cluster diagrams of c a l l associations in the repertoires of A), C pod, and B), the captive whale "Namu". See Figure 24 caption for d e t a i l s . 149 0.0 O 0.1 O o 0 2 00 oo < ii 0.3 X LJLJ 0.4 0.5 L 0.0 C Pod N7 N8 N16 N16 N1 N12 short long CALL TYPE Namu < o O 00 00 < X LU Q 0.1 Q2 -0.3 " 0.4 -0.5 N7 N8 N1 N16 N12 CALL TYPE 150 F i g u r e 28. Spectrograms of s e l e c t e d C-pod c a l l t y pes produced i n 1978-80 and by the c a p t i v e whale "Namu" C POD - 1978-80 N A M U " - 1 9 6 5 N1 i i i N1 i i i I " 1 0 500 ms 152 Table X. Degree of s i m i l a r i t y in dialects of A-clan pods. Values shown are the t o t a l number of c a l l types plus the number of subtypes shared for each pair of pods, and, in parentheses, the index of s i m i l a r i t y based on this number. See text for derivation of the index. POD A l A4 A5 B H A4 A5 B H I I 15 (.750) 15 (.789) 9 (.450) 6 (.353) 6 (.364) 10 (.571) 8 (.421) 16 (.842) 9 (.450) 6 (.353) 6 (.364) 10 (.571) 9 (.514) 8 (.421) 5 (.312) 5 (.323) 9 (.545) 7 (.389) 10 (.589) 9 (.545) 11 (.629) 14 (.737) 13 (.963) 8 (.522) 7 (.438) 8 (.571) 7 (.452) 12 (.727) 1 53 Figure 29. Cluster diagram of acoustic associations of A-clan pods. Association i s represented by an index of repertoire s i m i l a r i t y based on the degree of c a l l type and subtype sharing between pods. This index i s described more f u l l y in the text. 0.5 0.6 DC < 0.7 0.8 -0.9 -A - C l a n 1.0 L A1 A4 A5 B 11 POD H D 155 resulting diagram shows that within the A-group of pods, A4 and A5 tend to be more closely related a c o u s t i c a l l y than either i s to A1 pod. Sim i l a r l y , within the B-group, pods C and D form a d i s t i n c t subgroup with a high l e v e l of s i m i l a r i t y (0.963), and pods B, H and 11 form another subgroup with a somewhat lower degrees of homogeneity. It is noteworthy that 11 pod produces two versions of several c a l l types. Some are unique to the pod, while others are shared with B or, more often, H pod. The A-and B-groups of pods are related at the 0.571 l e v e l of s i m i l a r i t y . B. G-Clan The G-clan i s comprised of three pods, G, 111 and 131, with a t o t a l of 37 members (Table VIII). The clan has a repertoire of 15 c a l l types, one of which has two subtype forms. These c a l l s and the pods observed to produce them are l i s t e d in Table XI. Four of the G-clan c a l l types are used by a l l three pods. The remainder are made only by one or two of the pods. I_) C a l l c h a r a c t e r i s t i c s The most common c a l l of the G-clan pods is N23, which occurs in two variant forms, N23i and N23ii (Fig. 30). N23i i s shared by 111 and 131 pods and N23ii i s given exclusively by G pod.- It i s a two-part signal with a d i s t i n c t i v e , narrowband tone emitted simultaneously during part 1. Part 1 i s similar in both subtypes, but s i g n i f i c a n t differences in the structure of Part 2 distinguish the two subtypes. This component in N23i 156 T a b l e X I . C a l l t ypes and subtypes produced by pods o f the G c l a n i n the n o r t h e r n r e s i d e n t community. C a l l s G 111 131 C a l l s G 111 131 N23 —| i X X N40 X X X I ii X N41 X X X N24 X X N44 X N25 X X N45 X X N26 X X N46 X X N28 X N48 X X X N29 X N30 X X N38 X T o t a l 10 11 9 N39 X X 157 starts with an immediate drop in pitch to a mean of about 850 Hz, followed by an increase to approximately 1250 Hz, then a drop once again to about 400-475 Hz at the c a l l ' s end. Part 2 in N23ii, on the other hand, maintains a nearly constant pitch of s l i g h t l y more than 1000 Hz throughout, except for a s l i g h t drop to an average SBI of 726 Hz at the end of the c a l l . Pod 131's versions of subtype N23i had a terminal downsweep which was reduced in both duration (p < 0.001) and drop in pitch (p < 0.01) compared to 111. As a re s u l t , the average duration of the c a l l was almost 100 ms less in 131. Both subtypes of N23 are frequently preceded within 1 s by an 'introductory note' consisting of a short ( < 150 ms) pulse burst with SBI's of 100-150 Hz. Another c a l l which shows considerable pod-specific variation i s N25, used by pods G and 111, but not 131. The c a l l has a f a i r l y elaborate four-part structure, with an independent narrowband tone overlapping part 2 at about 7500 Hz (Fig. 30). Renditions of the c a l l d i f f e r s i g n i f i c a n t l y in many structural variables (Appendix I I I ) , but most d i s t i n c t i v e l y in the f i n a l part 4, which tends to be far shorter in most samples from G pod (means = 185 ms in G versus 637 ms in 111; p < 0.001). Despite t h i s marked difference, overlap in the measurements of this component was noted, and hence the versions were not assigned to discrete subtype categories. C a l l s N24, N26, N30 and N48, shown in Figure 31, are given exclusively by 111 and 131 pods, with the exception of N48 which has not been recorded from 131. N24 is a common c a l l in both 1 58 F i g u r e 30. Spectrograms of G - c l a n c a l l t y p e s N23 and N25. 1 60 Figure 31. Spectrograms of G-clan c a l l types N24, N26, N28, N29, N30, N44 and N48. 161 r o T 1 500 ms 1 62 repertoires and appears to d i f f e r in several aspects between the two pods. However, due to the small sample size for 1 3 1 , the v a l i d i t y of these differences cannot be determined. C a l l N 3 0 i s an unusual c a l l which often begins in the same manner as N 2 3 , but thereafter consists e n t i r e l y of rapid alternations of high and low pitch pulse-bursts, both of which have consistently higher SBI's in 1 3 1 pod's versions (p < 0 . 0 0 1 and P < 0 . 0 5 in low and high pitched components, respectively). C a l l s N 2 8 , N 2 9 and N 4 4 are given exclusively by G pod (Fig. 3 1 ) . Both N 2 8 and N 2 9 appear to be c l o s e l y related to N 2 3 in the f i r s t part, but the remaining portions d i f f e r in each c a l l . An introductory note, l i k e that which precedes N 2 3 ' s , occurs frequently just prior to the emission of c a l l s N 2 8 and N 2 9 . The G-clan has a r e l a t i v e l y large repertoire of six c a l l s , shown in Figure 3 2 , which are used mainly in low arousal contexts. However, not a l l of these are given by each pod (Table XI). A l l are short-duration signals and most have rather simple structures. An exception is N 4 1 , a c a l l used by a l l three pods, which occurs generally in four parts, each separated by a short gap. Part 1 i s very similar in structure to the introductory notes preceding many N 2 3 , N 2 8 and N 2 9 c a l l s , and may have a comparable role since N 4 1 ' S occur occasionally without this component. Introductory notes without a following c a l l are also heard during low-arousal contexts. 1 63 F i g u r e 32. Spectrograms of G - c l a n c a l l t y p e s N38, N39, N40, N41, N45 and N46. 164 1 65 I I ) C a l l use Frequency d i s t r i b u t i o n s of c a l l s produced recently by G-clan pods are i l l u s t r a t e d in Figure 33, along with the d i s t r i b u t i o n of c a l l s in a tape recorded during 1973, apparently in the presence of 111 and, possibly, 131 pods. These show that there is a strong dependence on c a l l N23 throughout the clan, especially in the case of 131 pod (61.8% of a l l 131 c a l l s recorded during 1981-83). The occurrence of most of the remaining c a l l types d i f f e r s markedly among the three pods. C a l l N24 is the second-most abundant c a l l in the repertoires of 111 and 131, representing 22.1% and 27.9%, respectively, of c a l l use, but i t i s not used by G pod. N25 is important in the c a l l i n g of G and 111, but i t was not recorded from 131 pod. Although the sample for 1973 i s small, the frequency d i s t r i b u t i o n and structure of c a l l s i s similar to that recorded recently from encounters with 111 and 131 pods foraging together. No photographic evidence of the pods present on the single encounter in that year i s available. Cal l s c h a r a c t e r i s t i c of G pod were not present in any pre-1978 tape examined. There are limited data on each pod's use of resting or low-arousal c a l l s . However, in several short encounters with a resting subgroup of G pod, N41 was the most common c a l l representing 66.7% of the 78 c a l l s recorded, followed by N40 (19.7%) and N38 (13.6%). C a l l N38 appears to be closely associated with N40, occurring t y p i c a l l y within 1 or 2 s of the l a t t e r . In 111 and 131, c a l l N46 i s the most frequently used 1 66 Figure 33. Frequency d i s t r i b u t i o n s of c a l l s produced by G-clan pods. Tape from 1973 i s assumed to have involved 111 and/or 131 pods on the basis of c a l l types recorded. 167 50-40-30-20-10H > O LU 3 o LU CC LU O DC LU CL 0-40-" 30-20-10-0— 30-20-10-0-60-50-40-30-20-10-0-G Pod 1980 -1983 111/131 Pods (?) 1973 111 Pod I 1 131 Pod I 1 n= 1660 calls n= 121 calls i i 1978 - 1983 n= 821 calls I r-1981-1983 n= 710 calls N23 N24 N25 N26 N28 N29 N30 N38 N39 N40 N41 N44 N45 N46 N48 CALL TYPE 168 r e s t i n g c a l l , r e p r e s e n t i n g 43.8% of 160 c a l l s r e c o r d e d from the two pods t o g e t h e r , f o l l o w e d by N40 ( 2 0 . 5 % ) , N41 ( 1 8 . 8 % ) , N45 (13.8%) and N39 ( 3 . 1 % ) . E x a m i n a t i o n of the a s s o c i a t i o n s of G - c l a n c a l l t y p e s on t h e b a s i s of t r a n s i t i o n f r e q u e n c i e s r e v e a l e d p a t t e r n s of use s i m i l a r t o o t h e r c l a n r e p e r t o i r e s . C a l l s a r e e m i t t e d t y p i c a l l y i n r e p e t i t i v e s e r i e s , and w i t h i n each pod's r e p e r t o i r e c e r t a i n c a l l s tend t o occur t o g e t h e r more o f t e n than by chance. In the r e p e r t o i r e of G pod, c a l l s N25 and N45 a r e the most s t r o n g l y a s s o c i a t e d , w i t h an inde x of 0.269 ( F i g . 34). T h i s a s s o c i a t i o n r e s u l t s from the tendency f o r N45's t o be g i v e n i m m e d i a t e l y p r i o r (< 2 s) t o the e m i s s i o n of an N25. A l t h o u g h many N25's were heard w i t h o u t an i n t r o d u c t o r y N45, few N45's o c c u r r e d a l o n e . C a l l s N23 and N29 o f t e n o c c u r t o g e t h e r , but N28 and N44 are not s t r o n g l y a s s o c i a t e d w i t h any p a r t i c u l a r c a l l . C a l l s N25 and N45 are a l s o r e l a t e d i n the same manner i n I l l ' s r e p e r t o i r e , but N45's are a l s o g i v e n commonly w i t h o u t a f o l l o w i n g N25, p r i m a r i l y d u r i n g l o w - a r o u s a l a c t i v i t i e s . Thus, the N25/N45 a s s o c i a t i o n i s not as c l e a r l y e v i d e n t i n the diagram of 111 c a l l r e l a t i o n s h i p s . As might be e x p e c t e d , the common c a l l s N23, N24 and N25, which dominate c a l l i n g i n the pod, f r e q u e n t l y o c c u r t o g e t h e r ( F i g . 3 4 ) . I l l ) Summary of a c o u s t i c a s s o c i a t i o n s : G - c l a n I t i s c l e a r t h a t r e p e r t o i r e s of pods 111 and 131 a r e more s i m i l a r t o each o t h e r than e i t h e r i s t o t h a t of G pod. I n d i c e s of s i m i l a r i t y based on s h a r i n g of c a l l t y p e s i n d i c a t e t h a t 111 1 69 Figure 34. Cluster diagrams of c a l l associations in the repertoires of pods G and 111. See Figure 24 caption for d e t a i l s . 0.0 z Q 0.1 O o CO S 0.2 X LU Q 0.3 0.4 0.0 G Pod N25 N45 N23 N29 N28 N44 CALL TYPE 111 Pod 1 0 1 o o CO CO < 0.2 X LU Q 0.3 -0.4 L N23 N25 N24 N45 N26 N30 CALL TYPE 171 and 131 are h i g h l y r e l a t e d a c o u s t i c a l l y w i t h an index of 0.909. Pods G and 111 have a lower s i m i l a r i t y l e v e l of 0.522, and G and 131 have an index of o n l y 0.381. C. R-Clan The R - c l a n i s a s m a l l a c o u s t i c a s s o c i a t i o n of two pods, R and W, which had 19 and 4 members, r e s p e c t i v e l y , i n 1982. The c l a n has a t o t a l r e p e r t o i r e of 8 c a l l t y p e s , N32, N33, N34, N35, N42, N43, N50 and N51, a l l of which a r e used by b o t h pods. C a l l N32 o c c u r s i n two subtype forms; N32i i s produced by both pods, but N 3 2 i i appears t o be made by R o n l y . I_) C a l l c h a r a c t e r i s t i c s The c a l l r e p e r t o i r e of R - c l a n pods i s i l l u s t r a t e d i n F i g u r e 35. The two most common c a l l s , N32 and N33, a r e s i m i l a r i n g e n e r a l s t r u c t u r e , except N33 has a s e r i e s of r a p i d m o d u l a t i o n s i n SBI b e f o r e t e r m i n a t i n g i n the same manner as N32. In subtype N 3 2 i i , the p i t c h i s c o n s t a n t or i n c r e a s e s s l i g h t l y over the f i r s t h a l f of the c a l l , then s h i f t s suddenly t o a h i g h e r SBI, i n c o n t r a s t t o the stea d y i n c r e a s e seen throughout N 3 2 i . Pod R's v e r s i o n of N32i appears t o be c o n s i s t e n t l y l o n g e r i n d u r a t i o n than W s (p < 0.05) and reaches a h i g h e r p i t c h i n p a r t 2 (p < 0.01). Of 17 f r e q u e n c y and d u r a t i o n v a r i a b l e s measured f o r c a l l N33, o n l y one d i f f e r e d s i g n i f i c a n t l y between the two pods; the d u r a t i o n of the low p i t c h m o d u l a t i o n f o l l o w i n g the f i r s t peak i n p a r t 2 was lower i n R (mean = 54 Hz) than W (mean = 195 Hz) (p < 0.001 ) . 172 F i g u r e 35. Spectrograms of R - c l a n c a l l t y p e s N32, N33, N34, N35, N36, N42, N43, N49, N50 and N51. C a l l N49 was r e c o r d e d o n l y i n tapes made d u r i n g August, 1964, a p p a r e n t l y i n the presence of R and/or W pods. 173 374 Of the r e m a i n i n g R - c l a n c a l l s , o n l y N35 shows c o n s i s t e n t p o d - s p e c i f i c v a r i a t i o n . In samples of t h i s f i v e - p a r t c a l l , p a r t s 1, 2 and 4 are s i g n i f i c a n t l y s h o r t e r i n W pod's v e r s i o n , r e s u l t i n g i n o v e r a l l d u r a t i o n s a v e r a g i n g 1056 ms i n R pod compared t o 612 ms i n W (p < 0.001). The s t r u c t u r e s of R - c l a n c a l l s r e c o r d e d i n 1964 and 1973 were examined and found to be s i m i l a r t o t h o s e o b t a i n e d from R and W pods r e c e n t l y . A l t h o u g h t o o few samples s u i t a b l e f o r s t a t i s t i c a l a n a l y s i s were o b t a i n e d f o r most c a l l t y p e s , N33 and N34 were w e l l r e p r e s e n t e d i n the e a r l y t a p e s . A number of N33 v a r i a b l e s d i f f e r s i g n i f i c a n t l y between 1964, 1973, and 1981-83 r e c o r d i n g s of R and W pods, but t h e r e i s no o b v i o u s t r e n d of change i n any component over the 19 year p e r i o d between the e a r l i e s t and most r e c e n t samples. In the case of N34, no s i g n i f i c a n t d i f f e r e n c e s are apparent i n 1964 v e r s u s 1981-83 samples from R or W pods. C a l l N49 ( F i g . 35) was p r e s e n t o n l y i n the 1964 r e c o r d i n g s . I I ) C a l l use The f r e q u e n c y d i s t r i b u t i o n s of R - c l a n c a l l s as r e c o r d e d i n 1964, 1973, and r e c e n t l y from R and W pods a r e shown i n F i g u r e 36. A l l c a l l s r e c o r d e d d u r i n g 1981-83 from these pods a r e p r e s e n t i n the 1964 sample, except the uncommon c a l l N51. However, c a l l N49, which c o m p r i s e d 8.06% of the 422 R - c l a n c a l l s a n a l y s e d from the 1964 t a p e s , was not r e p r e s e n t e d i n e i t h e r 1973 or 1981-83 samples. I t i s p o s s i b l e t h a t the c a l l has been l o s t from the r e p e r t o i r e s of R and W pods, or t h a t the c a l l was s p e c i f i c t o some R - c l a n pod not p r e s e n t i n the a r e a today. 1 75 Figure 36. Frequency d i s t r i b u t i o n s of R-clan c a l l s . 50-, 40 30 20 10 0 > 50-o z 40-tu 30-o LU 20-CC LL 10-H Z o-CE 40-cc 30-UJ CL 20-10-0-40-30-20-10-0-R / W Pods (?) 1964 n= 422 calls R / W Pods (?) 1973 n= 207 calls R Pod 1981-1982 n= 550 calls W Pod 1981-1983 n= 295 calls N32 N33 N34 N35 N42 N43 N49 N50 N51 CALL TYPE 177 Comparing the f r e q u e n c y of o c c u r r e n c e of the r e m a i n i n g c a l l s , no s i g n i f i c a n t d i f f e r e n c e s a re apparent i n the use of c a l l s N32, N33, N34, N35, or N43 between 1964 and r e c e n t r e c o r d i n g s of R or W. C a l l N42, however, i s s i g n i f i c a n t l y l e s s f r e q u e n t i n W's c a l l i n g than i n R's (0.7% vs 13.5%, p < 0.001). The uncommon c a l l s N50 and N51 were not t e s t e d , but they comprised s i m i l a r s m a l l p r o p o r t i o n s i n both e a r l y and r e c e n t samples. These s i g n a l s appear t o be a s s o c i a t e d w i t h l o w - a r o u s a l c o n t e x t s , as are c e r t a i n c a l l s i n the r e p e r t o i r e s of A- and G-c l a n pods d e s c r i b e d above. A n a l y s e s of t r a n s i t i o n f r e q u e n c i e s of the common c a l l s of R and W pods combined show s i g n i f i c a n t a s s o c i a t i o n s between c a l l t y p e s (G = 180.2, df = 16, p < 0.001). As i n o t h e r c l a n r e p e r t o i r e s , c a l l s t e n d t o occur t o g e t h e r i n b o u t s , t h u s t r a n s i t i o n s between t h e same c a l l type have s i g n i f i c a n t l y g r e a t e r - t h a n - e x p e c t e d o c c u r r e n c e s . I n d i c e s of a s s o c i a t i o n of d i f f e r e n t c a l l t y p e s ( F i g . 37) show t h a t the abundant c a l l s N32 and N33 te n d t o o c c u r t o g e t h e r , and t h e r e i s a s t r o n g a s s o c i a t i o n between c a l l s N34 and N43. I l l ) Summary of a c o u s t i c a s s o c i a t i o n s : R - c l a n The two pods making up the R - c l a n a r e v e r y c l o s e l y r e l a t e d i n c a l l use. The o n l y major d i f f e r e n c e appears t o be i n subtype N 3 2 i i , which i s made by R but not W pod. The index of r e p e r t o i r e s i m i l a r i t y between th e s e two pods e q u a l s 0.947, which i s among the h i g h e s t l e v e l s o b s e r v e d i n r e s i d e n t pods. 1 78 Figure 37. Cluster diagram of c a l l associations in the repertoires of R and W pods combined. 179 0.0 R & W Pods 0.1 -8 0 2 CO CO < X LU Q z 0.3 -0.4 -0.5 N32 N33 N42 N34 N43 CALL TYPE 180 3_. D i a l e c t s of Southern Community R e s i d e n t Pods. The s o u t h e r n community i s c o m p r i s e d of t h r e e pods, J , K and L, which belong t o a s i n g l e a c o u s t i c a s s o c i a t i o n r e f e r r e d t o as the J - c l a n . A t o t a l of 40 pod e n c o u n t e r s was made w i t h J - c l a n pods between 1978 and 1983; pod J was enc o u n t e r e d 18 t i m e s , K pod 10 t i m e s , and L pod on 12 o c c a s i o n s (Appendix I ) . K pod was enc o u n t e r e d a l o n e on o n l y two o c c a s i o n s . R e p e r t o i r e d e s c r i p t i o n i s based on these as w e l l as t h r e e K-pod r e c o r d i n g s made by R. Osborne ( M o c l i p s C e t o l o g i c a l S o c i e t y ) d u r i n g 1979-80. A. J - C l a n Pods J , K and L a r e c o m p r i s e d of 19, 10 and 50 i n d i v i d u a l s , r e s p e c t i v e l y (Table V I I I ) . L pod i s the l a r g e s t r e s i d e n t pod o c c u r r i n g i n the study a r e a . A t o t a l of 26 c a l l t y p e s , l i s t e d i n T a b l e X I I , was d e s c r i b e d from r e c o r d i n g s of J - c l a n pods. Four of thes e c a l l t y p e s have two or t h r e e d i s c r e t e s u b t y p e s . J pod has a t o t a l r e p e r t o i r e of 17 c a l l t y p e s , K pod has 10 c a l l s , and L pod has 15 c a l l s . Four c a l l s , S6, S8, S10 and S42, a r e shared by a l l t h r e e pods, 9 a r e g i v e n by two pods, and 13 a r e e x c l u s i v e t o s i n g l e pods. I_) C a l l c h a r a c t e r i s t i c s Of the 13 c a l l t y p e s shared by two or a l l t h r e e J - c l a n pods, 4 have d i s c r e t e s u b t y p e s . There a r e t h r e e subtypes of c a l l S2 ( F i g . 38). Subtypes S 2 i and S 2 i i , b o t h g i v e n by J pod, can be d i s t i n g u i s h e d by the pr e s e n c e of a downsweep a t the end of p a r t 3 i n S 2 i i . S 2 i i i , used e x c l u s i v e l y by L pod, l a c k s p a r t 181 T a b l e X I I . C a l l types and subtypes produced by pods o f the J c l a n i n the s o u t h e r n r e s i d e n t community. Pods Pods C a l l s J K L C a l l s J K L. S I X X S16 X X i X S17 X X S2 —\ i i X S18 X 1 i i i X S19 X S3 X S22 X S4 X X S31 X S5 X X S33 X S6 X X X S36 X S7 X X S37 — | i X S8 —| i X X I i i X 1 i i X S40 X S9 X S41 X S10 X X X S42 X X X S12 X S44 X S13H i X 1 i i X S14 X T o t a l 18 10 15 182 Figure 38. Spectrograms of J-clan c a l l types S2, S8, S13 and S37. 184 3 e n t i r e l y . No form of S2 c a l l was r e c o r d e d from K pod. The c h a r a c t e r i s t i c s h a r p upsweep i n the b r i e f c a l l S8 b e g i n s a t a h i g h e r SBI i n S 8 i , produced by J and K pods, than i n S 8 i i g i v e n by L pod (> 1500 Hz i n S 8 i r < 1000 Hz i n S 8 i i ; F i g . 3 8 ) . Another s h o r t d u r a t i o n two-part c a l l , S13 ( F i g . 38) a l s o o c c u r s i n two forms, one made e x c l u s i v e l y by J pod (S 1 3 i ) and the o t h e r by L pod ( S 1 3 i i ) . The two subtypes d i f f e r p r i m a r i l y i n the p i t c h of p a r t 1. In J-pod's v e r s i o n s , t h i s component c o n s i s t e n t l y r e a c h SBI's of > 3500 Hz, w h i l e i n L-pod samples, the SBI's were a l l < 3400 Hz. F i n a l l y , c a l l S37 i s g i v e n i n two forms; S37i i s used by J pod o n l y , and S 3 7 i i by L pod. The subtypes d i f f e r i n t h e p i t c h c o n t o u r of the second of t h e i r two-p a r t s ( F i g . 3 8 ) . The n i n e r e m a i n i n g J - c l a n c a l l s which a re used by more than one pod are i l l u s t r a t e d i n F i g u r e 39. C a l l s produced o n l y by J pod a r e shown i n F i g u r e 40, and those g i v e n by L pod a l o n e a r e shown i n F i g u r e 41. S18, a common c a l l i n L-pod's r e p e r t o i r e , has an i n t e r e s t i n g composite s t r u c t u r e . The main component of the c a l l i s a 250-600 ms p u l s e d t o n e , which i s u s u a l l y p r e c e ded by 3 or 4 (range = 0-9) 50-100 ms l o n g upsweeps, or ' c h i r p s ' , spaced about 200-250 ms a p a r t . O c c a s i o n a l l y , the c h i r p s a re heard w i t h o u t the p u l s e d t o n e , and v i c e v e r s a . A l t h o u g h u n r e l a t e d t o the c a l l t y p e s d i s c u s s e d h e r e , a n o t h e r noteworthy f e a t u r e of J - c l a n sound p r o d u c t i o n i s the tendency f o r w h i s t l e s t o occur i n l o n g , r e p e t i t i v e s e r i e s of p u l s e s , e s p e c i a l l y d u r i n g s o c i a l i z i n g a c t i v i t i e s . Each w h i s t l e p u l s e i s 100-400 ms i n d u r a t i o n , and has a c o n s t a n t p i t c h w i t h i n a bandwidth of about 4000 t o 8000 1 85 Figure 39. Spectrograms of J-clan c a l l types SI, S4, S5, S6, S7, S10, S16, S17, and S42. 186 I —r 0 I 500 ms 187 F i g u r e 40. Spectrograms of c a l l t y p e s S3, S9, S12, S14, S41, S44, g i v e n o n l y by J pod. 188 189 F i g u r e 41. Spectrograms of c a l l t y p e s S18, S19, S22, S31, S33, S36, S40, g i v e n o n l y by L pod. 190 .191 Hz. These p u l s e s a re r e p e a t e d at r a t e s of about 1-8/s f o r p e r i o d s of 3 t o > 30 s. O f t e n , w h i s t l e p u l s e s w i t h i n a s e r i e s are g i v e n at a l t e r n a t i n g f r e q u e n c i e s up t o 3000 Hz a p a r t . S e r i e s of p u l s e d w h i s t l e s were not r e c o r d e d from any o t h e r c l a n . 11) C a l l use The frequency of o c c u r r e n c e of c a l l t y p e s produced by J pod d u r i n g f o r a g i n g and t r a v e l l i n g i n 1979-83 are i l l u s t r a t e d i n F i g u r e 42. As d e s c r i b e d i n P a r t I , t h e r e a r e many s i g n i f i c a n t d i f f e r e n c e s i n c a l l use between these a c t i v i t i e s i n t h i s pod. C a l l s S1, S4 and S7 tend t o predominate i n f o r a g i n g c o n t e x t s , w h i l e S2, S44, S42, and S1 a r e , i n t h a t o r d e r , the most imp o r t a n t c a l l s d u r i n g t r a v e l l i n g . S i x c a l l s r e c o r d e d d u r i n g f o r a g i n g e p i s o d e s were not hea r d d u r i n g t r a v e l l i n g . C a l l s S14 and S41 were e x c l u s i v e t o t r a v e l l i n g c o n t e x t s . A n a l y s e s of t r a n s i t i o n f r e q u e n c i e s among common c a l l s i n d i c a t e t h a t c a l l o c c u r r e n c e i s non-random i n f o r a g i n g (G = 1990.9, df = 49, p < 0.001) and t r a v e l l i n g (G = 341.2, df = 49, p < 0.001). Much of t h i s v a r i a t i o n r e s u l t s from the tendency f o r c a l l s t o occur i n r e p e t i t i v e s e r i e s , as i n n o r t h e r n r e s i d e n t pods. C l u s t e r diagrams of c a l l a s s o c i a t i o n s based on t r a n s i t i o n f r e q u e n c i e s ( F i g . 43) i n d i c a t e t h a t no J-pod c a l l s a r e s t r o n g l y l i n k e d . I examined t h r e e h i s t o r i c a l f i e l d r e c o r d i n g s made a p p a r e n t l y i n the presence of J pod. The e a r l i e s t was made on Feb r u a r y 19, 1958, i n S a a n i c h I n l e t , Vancouver I s l a n d , i n the presence of an e s t i m a t e d 18 whales. J pod i s the o n l y r e s i d e n t group which has been seen a t t h i s l o c a t i o n s i n c e 1973 (M. B i g g , 1 92 F i g u r e _ 4 2 . Frequency d i s t r i b u t i o n s of J. pod c a l l s r e c o r d e d i n f o r a g i n g and t r a v e l l i n g c o n t e x t s , 1979-83. 50 40-304 O 20-104 0-Foraging 1979-1983 n= 3801 calls 40-30 H 20 -\ 10H o-Travelling 1979-1983 n= 2204 calls S1 S2i S2ii S3 S4 S5 S6 S7 S8 S9 S10 S12 S13 S14 S37 S41 S42 S44 CALL TYPE 1 94 Figure 43. Cluster diagram of c a l l associations in the repertoire of J pod. See Figure 24 caption for d e t a i l s . 0.0 0.1 0.2 0.3 L J Pod Foraging S1 S4 S3 S7 S12 S6 S5 CALL TYPE < o o co CO < X LU Q Z 0.0 0.1 0.2 0.3 J Pod Travelling S2 S44 S42 S1 S41 S37 CALL TYPE 1 96 pers. comm.). This tape contains a t o t a l of 9 c a l l types. A l l are from the 17-call repertoire used by J pod in 1979-83. The frequency d i s t r i b u t i o n of c a l l s most clos e l y resembles that of J-pod's c a l l production while t r a v e l l i n g , although there are differences in emphases. The second recording i s from October 20, 1960, in Dabob Bay, Puget Sound. This short sample primarily contains c a l l s S2, S14 and S1. The t h i r d tape, dated 'spring 1961', was again recorded in Saanich In l e t . It also contains 9 J-pod c a l l types, but their i d e n t i t y and frequency of use i s more t y p i c a l of recent c a l l production during foraging contexts. Combining these recordings, i t i s evident that at least 14 of the present 17 J-pod c a l l types existed in 1961 or e a r l i e r . Although the samples are too small to draw firm conclusions, c a l l S14 appears to have been more important in J -pod's repertoire in the early 1960's than in 1979-83. This c a l l comprised 12.2% and 18.3% of the t o t a l recorded in 1958 and 1960, respectively, although i t did not occur in the 1961 sample. Two whales captured in the southern community area in 1964 and 1965, apparently from J pod, also used S14 frequently. The c a l l accounted for 13.9% of those produced in 1964 by "Moby D o l l " , a young b u l l , and 9.8% for the female "Shamu" in 1965 (Fig. 44). C a l l S14 was not recorded from J pod while foraging in 1978-83, and comprised only 0.4% of travelling-context c a l l production in the same period. Too few encounters were made with K pod alone to confidently describe the frequency d i s t r i b u t i o n of c a l l s in t h i s 1 97 Figure 44. Frequency d i s t r i b u t i o n s of J-pod c a l l types recorded during 1958-61, and from the captive whales "Moby D o l l " and "Shamu". There i s no photographic evidence that J pod was involved in these early f i e l d encounters, or that the two captive whales were taken from J pod. 20-10-0-1958 n. 197 calls ] 1960 n» 48 calls 1961 n» 243 calls 1 1 Moby Doll" 1964 n- 316 calls Shamu" 1965 n« 345 calls S S2i S2ii S3 S4 S5 S6 S7 S8 S9 S10 S12 S13 S14 S37 S41 S42 S44 C A L L T Y P E 1 99 group. However, S16, S17, S1 and S4 appeared t o be the c a l l s most commonly used. C a l l p r o d u c t i o n by L pod i s i l l u s t r a t e d i n F i g u r e 45. As i n J pod, t h e r e i s a s i g n i f i c a n t s h i f t i n c a l l emphasis i n f o r a g i n g v e r s u s t r a v e l l i n g c o n t e x t s . C a l l t r a n s i t i o n f r e q u e n c i e s i n d i c a t e t h a t c a l l S16 i s f r e q u e n t l y f o l l o w e d w i t h i n 2-4 s by an S17, and S18 i s o f t e n f o l l o w e d by an S22. The a s s o c i a t i o n of c a l l s S16 and S17 a l s o o c c u r s i n K-pod's c a l l i n g . C a l l i n t e n s i t y p a t t e r n s suggested t h a t b o t h c a l l s i n each p a i r were g i v e n by the same i n d i v i d u a l . These and o t h e r c a l l a s s o c i a t i o n s a r e shown i n F i g u r e 46. The e a r l i e s t r e c o r d of L-pod c a l l s i s from a tape made i n the presence of f o u r a n i m a l s t a k e n i n two c a p t u r e s and h e l d t o g e t h e r a t Pedder Bay, near V i c t o r i a , B.C., i n 1973. Of t h e s e 4 whales, 2 were from K pod, and the o t h e r 2 were from an undetermined group ( B i g g e t a l . , 1976; B i g g , p e r s . comm.). The sample r e c o r d i n g from th e s e a n i m a l s c o n t a i n s c a l l s which c l o s e l y match those produced by L pod w h i l e f o r a g i n g i n 1980-83 ( F i g . 45) . I l l ) Summary of a c o u s t i c a s s o c i a t i o n s ; J - c l a n I n d i c e s of s i m i l a r i t y i n J - c l a n c a l l r e p e r t o i r e s a re r a t h e r low i n comparison t o thos e of n o r t h e r n community c l a n s . T h i s i s l a r g e l y a r e s u l t of the numerous c a l l s e x c l u s i v e t o e i t h e r J or L pods. Pods J - and K are most s i m i l a r a c o u s t i c a l l y w i t h an index of 0.545. Next i s K and L w i t h an index of 0.387, and f i n a l l y J and L a t 0.333. K pod a p p a r e n t l y produces no unique c a l l s . Of t h e 10 c a l l t y p e s g i v e n by K pod, 4 a r e shared w i t h J 200 F i g u r e 45. Frequency d i s t r i b u t i o n s of c a l l s produced by L pod w h i l e f o r a g i n g and t r a v e l l i n g d u r i n g 1980-83, and from c a p t i v e whales i n 1973. 201 30-. 20-10->-o z LU o LU CC LU O 0C LU CL 0-30-20-10-" 0-40-30-20-10-0-Pedder Bay Capture 1973 n= 102 calls Foraging 1980-1983 n= 1980 calls i I 1 U Travelling 1980 n= 332 calls S2 S8 S10 S13 S16 S17 S18 S19 S22 S31 S33 S36 S37 S40 S42 CALL TYPE 202 Figure 46. Cluster diagram of c a l l associations in the repertoire of L pod. See Figure 24 caption for d e t a i l s . 0.0 0.1 < g 0.2 UL O 0.3 0.4 L Pod 0.5 L. S18 S22 S19 S2 S40 S36 S16 S17 S31 CALL TYPE 2.0.4 pod only, 2 with L, and 4 with both J and L. 4. Comparison of Dialect S i m i l a r i t y and Pod Distri b u t i o n s. Of the four resident clans, only J-clan, which comprises the entire southern resident community, appears to have an exclusive range. The di s t r i b u t i o n s of the three norhern resident clans overlap widely. The frequency of occurrence of northern resident pods off northeastern Vancouver Island during 1978-83 i s shown in Figure 47. Although a l l pods in the community do occur in the area , pod d i s t r i b u t i o n i s c l e a r l y non-random. Pods A1, A4 and A5 were by far the most common (each present on > 48% of encounter days), followed by B pod,, which was seen on 25.8% of the t o t a l days whales were encountered. The remaining A-clan pods were each seen on < 16% of the days. A l l three G-clan pods were r e l a t i v e l y uncommon i n the area. Of the three, 111 was the most often observed, being present on 13.3% of encounter days. The two R-clan pods, R and W, were the rarest in the area. R pod was seen on only 3 days (2.3%) and W on only 9 days (7.0%). Pod occurrence also varied from year to year. The three A-pods were the most consistently seen, although A1 pod apparently l e f t the study area for most of the 1980 f i e l d season (July-October). Many of the less common pods appeared sporadically. Some were observed several times in certain years, but not at a l l in others (Appendix I ) . These patterns of occurrence suggest that pods have preferred areas within the ove r a l l range of the northern 205 F i g u r e 47. Frequency of o c c u r r e n c e of n o r t h e r n r e s i d e n t pods o f f n o r t h e a s t e r n Vancouver I s l a n d , 1978-83. P e r c e n t a g e s shown are the p r o p o r t i o n of days t h a t each pod was p r e s e n t i n the t o t a l 128 days t h a t whales were o b s e r v e d i n the a r e a . N = 386 pod e n c o u n t e r s CO cc LU 3 o o Z LU U_ O 80-60-40-A-Clan G - C l a n R-Clan 1 r 1 r LU O 20-LU 0. 0-A1 A4 A5 B H 11 POD G 111 131 W O CT> 207 community. The waters off northeastern Vancouver Island, especially Johnstone S t r a i t , appear to be the 'core area' of pods A1, A4 and A5. A l l three of these pods were absent on only 18 of the 128 days (14.1%) that whales were observed in the area during 1978-83. The remaining A-clan pods, as well as G- and R-clans, spend more time outside the study area, probably to the north and west. Unfortunately, too few encounters have been made in such regions to ide n t i f y potential core areas for these pods. There i s some indication that R-clan may reside predominately in the northern portions of the community range. On four of the eight occasions R pod was encountered between 1975 and 1983, the pod was north of Bella B e l l a , some 200 km north of the Johnstone S t r a i t area. W pod has been sighted at Prince Rupert, near the northern-most known l i m i t of the range of the northern community.. Pods B (A-clan), 111 and 131 (G-clan) have also been sighted in the northern part of the community range and, along with W, off the central west coast of Vancouver Island. The three A-pods have not been seen in either of these areas. In summary, the southern resident community i s comprised of a unique acoustic group - the J-clan - with an exclusive geographic range. In the northern community, the three a c o u s t i c a l l y - d i s t i n c t clans overlap geographically, although each may have separate core areas within the community range. In the case of the A-clan, pods A1, A4 and A5, which form an acoustic subgroup (Fig. 29), appear to have a di f f e r e n t core area from the remainder of the clan. It should be noted that 208 the m a j o r i t y of n o r t h e r n r e s i d e n t e n c o u n t e r s were made i n the months of June-October. Pod d i s t r i b u t i o n s a t o t h e r t i m e s of the year a r e m o s t l y unknown. 5. Comparison of D i a l e c t S i m i l a r i t y and Pod A s s o c i a t i o n s . To examine the r e l a t i o n s h i p between r e p e r t o i r e s i m i l a r i t y and the degree of s o c i a l a s s o c i a t i o n of pods, an index of a s s o c i a t i o n ( D i c e ' s i n d e x , d e s c r i b e d i n Morgan e t a l . (1976)) was c a l c u l a t e d from the t o t a l number of days each p a i r c o m b i n a t i o n of pods was s i g h t e d t o g e t h e r . To p r o v i d e as l a r g e a sample as p o s s i b l e , a l l e n c o u n t e r s c a r r i e d out or documented by M. B i g g ( p e r s . comm.) p r i o r t o and d u r i n g t h i s s t u d y , were i n c l u d e d i n the a n a l y s i s . The a s s o c i a t i o n m a t r i x f o r the n o r t h e r n r e s i d e n t community (Table X I I I ) r e p r e s e n t s a t o t a l of 773 pod e n c o u n t e r s made on 353 days between 1973 and 1983, f o r an average of 2.19 pods/day. As i s e v i d e n t from the d e s c e n d i n g d i a g o n a l of the m a t r i x , t h e r e i s c o n s i d e r a b l e v a r i a t i o n i n the number of o c c a s i o n s each pod was e n c o u n t e r e d w h i l e t r a v e l l i n g a l o n e . To a r r i v e a t an a c c u r a t e measure of i n t e r - p o d a s s o c i a t i o n u n a f f e c t e d by each pod's degree of s o c i a b i l i t y , t h e s e ' l o n e ' e n c o u n t e r s were removed from the t o t a l f o r each pod b e f o r e c a l c u l a t i o n of the a s s o c i a t i o n i n d e x . S i n c e the d i s t r i b u t i o n of n o r t h e r n r e s i d e n t pods i s non-random, and most sa m p l i n g was c a r r i e d out i n a s m a l l p o r t i o n of the community range, the a s s o c i a t i o n i n d i c e s must be i n t e r p r e t e d w i t h c a r e . As mentioned p r e v i o u s l y , the main study a r e a of 209 Table XIII. Social associations of northern resident community pods. Based on 773 pod encounters made on 353 days between 1973 and 1983. Values along descending diagonal (e.g., A1 with A1) are number of occasions pod was seen alone, and, in parentheses, the proportion of t o t a l encounters. A l l other values are the number of encounters d i f f e r e n t pods were observed in association, and an index of association in parentheses. This index i s explained in d e t a i l in the text. POD A l A4 A5 B C 0 G H I I 111 131 A l 28 (.169) A4 79 (.678) 6 (.059) A5 102 (.734) 76 (.647) 39 (.218) B 28 (.303) 17 (.239) 30 (.321) 33 (.413) C 23 (.267) 17 (.264) 20 (.230) 6 (.148) 3 (.081) D 11 (.131) 11 (.176) 24 (.283) 6 (.156) 11 (.343) 2 (.063) G 15 (.182) 10 (.164) 14 (.168) 10 (.270) 4 (.131) 3 (.105) 19 (.413) H 16 (.190) 9 (.144) 15 (.176) 9 (.234) 6 (.188) 4 (.133) 5 (.175) 1 (.032) 11 5 (.067) 4 (.075) 4 (.053) 3 (.102) 1 (.043) 2 (.095) 1 (.051) 7 (.333) 10 (.454) 111 13 (.153) 8 (.126) 14 (.163) 8 (.203) 6 (.182) 2 (.065) 14 (.475) 6 (.194) 3 (.136) 3 (.086) 131 9 (.115) 8 (.140) 12 (.151) 3 (.091) 3 (.113) 1 (.041) 6 (.261) 6 (.245) 4 (.258) 16 (.627) 1 (.050) R 3 (.042) 3 (.061) 3 (.042) 1 (.039) 2 (.105) 0 3 (.194) 3 (.176) 1 (.125) 2 (.111) 2 (.174) W 9 (.118) 8 (.145) 6 (.077) 2 (.065) 6 (.245) 0 7 (.333) 3 (.133) 2 (.148) 12 (.511) 7 (.412) TOTAL 166 101 179 80 37 32 46 31 22 35 20 4 (.500) 2 1 (.210) (.063) 16 21 1 northern Johnstone S t r a i t appears to be the core area for pods A l , A4 and A5. Other pods entered t h i s area i r r e g u l a r l y and usually joined with the A-pods for the duration of their v i s i t . Thus, the high index values between the three A-pods and many other northern community pods are very l i k e l y over-representations of the actual long-term relationships of these pods outside of Johnstone S t r a i t . Almost a l l northern resident pods have been observed to associate with each other. The only exception i s D pod, which was not seen with R or W pods. Within the A-clan, there is a clear c o r r e l a t i o n between the close associations of pods A1, A4 and A5, and their similar c a l l repertoires (Fig. 29). Among the B-group of pods, C and D have the most similar d i a l e c t s in the northern community with an index of s i m i l a r i t y of 0.963. Each of these two pods associated more with the other than any other northern community pod, although the association index of 0.343 is not p a r t i c u l a r l y high. The second strongest association value for C pod is with W pod of the R-clan (0.245). Pods B, H and 11 form a r e l a t i v e l y d i s t i n c t acoustic subgroup within the clan, and in some cases t h i s i s ref l e c t e d in their s o c i a l r e l a t i o n s h i p s . Pods H and 11 have an association index of 0.333, the highest value for both pods. Pod B, however, has a higher association index with G pod (0.270) than any northern resident except the A-pods. B's association with H is higher than other A-clan pods, again excluding the A-pods, but i t has a weak association with 11 (0.102). Of the three G-clan pods, 111 and 131.are closely related 212 i n both d i a l e c t ( s i m i l a r i t y i n d e x = 0.909) and o c c u r r e n c e ( a s s o c i a t i o n index = 0.627). G pod's h i g h e s t a s s o c i a t i o n index was w i t h 111 (0.475), but i t s a s s o c i a t i o n w i t h 131 was lower (0.261) than w i t h W pod ( 0 . 3 3 3 ) . W i t h i n the R - c l a n , t h e r e was l i t t l e i n d i c a t i o n from o c c u r r e n c e p a t t e r n s of the c l o s e a c o u s t i c r e l a t i o n s h i p between R and W pods. A l t h o u g h the h i g h e s t a s s o c i a t i o n index f o r R pod i s w i t h W, h i g h e r v a l u e s occur between W and pods C, G, 111 and 131. I n t e r - p o d a s s o c i a t i o n s i n the s o u t h e r n r e s i d e n t community are c o n f i n e d t o the t h r e e J - c l a n pods (Table X I V ) . The s t r o n g e s t a s s o c i a t i o n i s between K and L ( a s s o c i a t i o n index = 0.461). J pod a s s o c i a t e s t o a s i m i l a r degree w i t h both K (0.353) and L (0.337). J pod appears t o spend most time w i t h i n G e o r g i a S t r a i t and Puget Sound, w h i l e K and L pods t r a v e l r e g u l a r l y t h r o u g h Juan de Fuca S t r a i t t o a r e a s o f f the west c o a s t of Vancouver I s l a n d . A c o u s t i c r e l a t i o n s h i p s w i t h i n the J - c l a n do not c o i n c i d e c l o s e l y w i t h t h e s e a s s o c i a t i o n s . Pods J and K have the h i g h e s t d i a l e c t s i m i l a r i t y index of 0.545, f o l l o w e d by K and L (0.387) and J and L (0.333). I t i s p o s s i b l e t h a t s o c i a l r e l a t i o n s h i p s have changed r e c e n t l y as a r e s u l t of s i g n i f i c a n t c r o p p i n g of whales from 1967 t o 1973. D u r i n g t h i s p e r i o d , an e s t i m a t e d 27% of the t o t a l s o u t h e r n r e s i d e n t p o p u l a t i o n was c a p t u r e d and removed f o r d i s p l a y i n o c e a n a r i a ( B i g g 1982). Changes i n group c o m p o s i t i o n may have a l t e r e d the p a t t e r n of pod a s s o c i a t i o n s d u r i n g the p r e s e n t s t u d y , and thus i t i s u n c l e a r whether the l a c k of c o r r e l a t i o n between d i a l e c t s i m i l a r i t y and pod T a b l e XIV. S o c i a l a s s o c i a t i o n s o f s o u t h e r n r e s i d e n t community pods. See c a p t i o n o f e x p l a n a t i o n o f T a b l e X I I I v a l u e s . f o r POD J K L J 105 (.761) Q O ft K 30 (.353) 8 (.133) L 28 (.337) 47 (.461) 30 (.375) TOTAL: 138 60 80 214 interaction i s representative of the natural state. In summary, the major vocal differences between the northern and southern resident communities correlate well with the i r geographic and so c i a l segregation. Within each community, however, the picture is less clear. The three a c o u s t i c a l l y -d i s t i n c t clans of the northern community interact s o c i a l l y , but the patterns of pod associations observed are, in many cases, inconsistent with d i a l e c t relationships. This may be a result of the non-random d i s t r i b u t i o n of pods and a sampling emphasis in one portion of the community range. Social relationships in the southern community may have been altered by recent cropping. 215 DISCUSSION The patterns of vocal variation in resident k i l l e r whales of B.C. may be summarized as follows. Each pod has a set of 7 to 17 discrete c a l l types that dominates vocalization in most contexts. A l l pod members appear to use the entire c a l l repertoire (Part I ) . Each pod shares several c a l l types with other pods, but may also produce unique c a l l s . Shared c a l l s often d i f f e r in form among pods. The 16 resident pods can be arranged into four a c o u s t i c a l l y - d i s t i n c t groups, or clans. Pods within each clan share c a l l types, but no sharing occurs between clans. The geographic d i s t r i b u t i o n s of 3 of the 4 clans overlap extensively, and pods from d i f f e r e n t clans commonly associate. Vocal variation thus exists at two levels in the resident population, (1) between pods within a clan, involving modification of c a l l structure and use, and frequent occurrence of c a l l types unique to a portion of the clan, and (2) between clans, involving complete independence of c a l l repertoires. A summary of acoustic relationships in the resident population i s i l l u s t r a t e d in Figure 48. The forms of vocal v a r i a t i o n described here appear, to be unique to k i l l e r whales for several reasons. With the exception of humans, no other mammalian species has populations that d i f f e r a c o u s t i c a l l y at a l o c a l l e v e l . A l l previously documented cases of vocal variation involve geographically-isolated groups (Connor 1982; Ford and Fisher 1983). Different acoustic groups of k i l l e r whales can not only exist in the same area, but may also associate regularly. In birds, d i a l e c t s occur among 2 1 6 Figure 48. Summary of acoustic relationships of resident pods in B r i t i s h Columbia The two resident communities have exclusive ranges, while clans have exclusive c a l l t r a d i t i o n s . The three northern community clans associate with each other. A l l pods within a clan share c a l l s , yet each may also have unique c a l l s . The degree of acoustic s i m i l a r i t y in the clan i s expressed as an index value, described in the text, and displayed by cluster analysis. 217 C O M M U N I T Y C L A N POD N O R T H E R N RESIDENT 13 pods A 8 pods G 3 pods R 2 pods f L- D A1 A4 A5 B 11 H C L" 111 131 G R W S O U T H E R N RESIDENT 3 pods J 3 pods J K L j 0.25 0.5 0.75 1-0 Acoustic Similarity Index 218 n e i g h b o u r i n g p o p u l a t i o n s , but a r e n e a r l y always t i e d t o s p e c i f i c g e o g r a p h i c l o c a l i t i e s (Krebs and Kroodsma 1980). F l o c k - s p e c i f i c v a r i a t i o n o c c u r s i n a few b i r d s p e c i e s ( e . g . , Feekes 1982; N o w i c k i 1983), but such groups a r e t e r r i t o r i a l . D i a l e c t s i n b i r d s u s u a l l y i n v o l v e r e l a t i v e l y minor m o d i f i c a t i o n s of a g e n e r a l song format t h a t i s common t o the s p e c i e s ( e . g . , T r a i n e r 1983). In s p e c i e s w i t h l a r g e song r e p e r t o i r e s , b i r d s from n e i g h b o u r i n g p o p u l a t i o n s t y p i c a l l y share some song t y p e s y e t have o t h e r s t h a t a re d i f f e r e n t (Krebs and Kroodsma 1980). In k i l l e r w h ales, pods o c c u r i n g i n the same ar e a can have e n t i r e l y d i f f e r e n t r e p e r t o i r e s of c a l l s . I n t e r p r e t a t i o n of the o r i g i n and p o s s i b l e a d a p t i v e s i g n i f i c a n c e of v o c a l v a r i a t i o n i n k i l l e r whales r e q u i r e s c o n s i d e r a t i o n of the f u n c t i o n of d i s c r e t e c a l l r e p e r t o i r e s and how i n d i v i d u a l s a c q u i r e t h e s e c a l l s . As d i s c u s s e d i n P a r t I , d i s c r e t e c a l l s i n g e n e r a l p r o b a b l y s e r v e t o m a i n t a i n c o n t a c t among pod members d u r i n g p e r i o d s of d i s p e r s i o n . There i s a poor c o r r e l a t i o n of most c a l l t y p e s w i t h b e h a v i o u r a l c o n t e x t . The f i n e s t r u c t u r e of d i s c r e t e c a l l s and the i n c i d e n c e of v a r i a b l e and a b e r r a n t v o c a l i z a t i o n s a re b e t t e r i n d i c a t o r s of the s t a t e of a r o u s a l of the whales than a r e p a r t i c u l a r c a l l t y p e s . Whether d i f f e r e n t c a l l s have d i f f e r e n t meanings t o the a n i m a l s i s unknown, and why they have such l a r g e r e p e r t o i r e s remains u n c l e a r . As w i l l be d i s c u s s e d below, the f a c t t h a t c a l l s v a r y among s o c i a l groups may p r o v i d e c l u e s as t o t h e i r f u n c t i o n . I t i s p r o b a b l e t h a t k i l l e r - w h a l e c a l l r e p e r t o i r e s a r e l e a r n e d r a t h e r than i n h e r i t e d by i n d i v i d u a l s . T h i s i s i n 219 c o n t r a s t t o v o c a l development i n most o t h e r mammals, which i s c o n s i d e r e d t o be under complete g e n e t i c c o n t r o l (Nottebohm 1972, 1975; E h r e t 1980; but see Newman and Symmes 1983). The f a m i l y D e l p h i n i d a e , which i n c l u d e s the k i l l e r whale, i s the o n l y non-human mammalian group known t o have the a b i l i t y t o mimic and l e a r n new v o c a l p a t t e r n s ( T a y l e r and Saayman 1973; C a l d w e l l and C a l d w e l l 1972; Herman 1980) (a s i n g l e e x c e p t i o n t o t h i s i n v o l v e d c e r t a i n c a l l s t h a t developed a r t i f i c a l l y i n t h r e e t r o o p s of Japanese monkeys (Green 1975b)). Whether l e a r n i n g p l a y s a s i g n i f i c a n t r o l e i n the normal development of a d u l t v o c a l b e h a v i o u r i n d e l p h i n i d s has y e t t o be d e t e r m i n e d , a l t h o u g h i t i s g e n e r a l l y assumed t o be imp o r t a n t ( e . g . , C a l d w e l l and C a l d w e l l 1 979) . K i l l e r whales share the c a p a c i t y f o r v o c a l l e a r n i n g w i t h o t h e r d e l p h i n i d s . O c c a s i o n a l l y , i n d i v i d u a l s i n the w i l d w i l l i m i t a t e c a l l t y p e s b e l o n g i n g t o d i f f e r e n t pods, even those from o t h e r c l a n s ( P a r t I ) . In c a p t i v i t y , a j u v e n i l e male n o r t h e r n r e s i d e n t from A5 pod housed t o g e t h e r w i t h a s o u t h e r n community female from K pod a c q u i r e d s e v e r a l c a l l s of the female and f o r a time used t h e s e i n p r e f e r e n c e t o h i s n a t a l c a l l s ( F o r d , u n p u b l . ) . Another case i n v o l v e s the b u l l "Namu", taken from the n o r t h e r n r e s i d e n t C pod ( A - c l a n ) i n 1965. As d e s c r i b e d e a r l i e r , the numerous c a l l s p r e s e n t i n s e v e r a l r e c o r d i n g s of t h i s a n i m a l made s h o r t l y a f t e r c a p t u r e a r e t y p i c a l of those produced by the pod i n r e c e n t y e a r s ( F i g s . 26, 27 and 28 ) . However, f o r a p e r i o d of 3 min i n one r e c o r d i n g , Namu a p p a r e n t l y s w i t c h e d from h i s t y p i c a l r e p e r t o i r e and e m i t t e d s e v e r a l examples of c a l l s N2, 220 N4, N 7 i , and N 8 i , a l l unique t o pods A l , A4 and A5, and c a l l s N33 and N34, unique t o R and W pods. I t t h e r e f o r e seems most p r o b a b l e t h a t l e a r n i n g i s i n v o l v e d i n the a c q u i s i t i o n of an i n d i v i d u a l ' s c a l l r e p e r t o i r e and thus i n the development of g r o u p - s p e c i f i c d i a l e c t s i n k i l l e r w h a les. I t i s noteworthy t h a t development of l o c a l d i a l e c t s i n b i r d s i s dependent on song i m i t a t i o n and l e a r n i n g (see r e v i e w s by Nottebohm 1972; Krebs and Kroodsma 1980; Mundinger 1980). O r i g i n s of V o c a l V a r i a t i o n B e f o r e d i s c u s s i n g the p o t e n t i a l f u n c t i o n of k i l l e r whale v o c a l v a r i a t i o n , I w i l l c o n s i d e r the p r o x i m a t e f a c t o r s r e s p o n s i b l e f o r i t s development. V o c a l v a r i a t i o n s o c c u r a t two l e v e l s among r e s i d e n t whales, (1) w i t h i n c l a n s , and (2) between c l a n s . Pods w i t h i n a c l a n a l l s h a r e c a l l s , many of which v a r y i n s t r u c t u r e from pod t o pod. I n s t u d i e s of b i r d song, systems of r e l a t e d d i a l e c t s a r e r e f e r r e d t o as " l o c a l song t r a d i t i o n s " (Payne et a l . 1981) or " c u l t u r a l i n s t i t u t i o n s " (Mundinger 1980). Mundinger (1980) d e f i n e s a c u l t u r a l i n s t i t u t i o n as a " s i n g l e l i n e a g e of a n c e s t r a l descendant p o p u l a t i o n s of models (= a c q u i r e d b e h a v i o u r a l t r a i t s ) t h a t m a i n t a i n s i t s i d e n t i t y from o t h e r such l i n e a g e s and which has i t s own e v o l u t i o n a r y t e n d e n c i e s and h i s t o r i c a l f a t e . " " B o u n d a r i e s " between i n s t i t u t i o n s a r e g e n e r a l l y m a i n t a i n e d by g e o g r a p h i c a l or s o c i a l i s o l a t i o n . By t h i s d e f i n i t i o n , each c l a n of r e s i d e n t pods c o r r e s p o n d s t o a d i s t i n c t c u l t u r a l i n s t i t u t i o n o r ' c a l l t r a d i t i o n ' , made up 221 of an e x c l u s i v e s et of r e l a t e d c a l l d i a l e c t s . As Mundinger (1980) p o i n t e d out w i t h r e s p e c t t o house f i n c h (Carpodocus mexicanus) song, each i n s t i t u t i o n i s comparable i n o r g a n i z a t i o n a l terms t o a d i f f e r e n t human language. Languages c o n s i s t of e x c l u s i v e (or n e a r l y so) v o c a b u l a r i e s which o f t e n have s u b s t r u c t u r e s of e v o l u t i o n a r i l y - r e l a t e d speech d i a l e c t s . How d i d these c o m p l e t e l y d i f f e r e n t c a l l t r a d i t i o n s of the f o u r r e s i d e n t c l a n s come t o oc c u r on the B r i t i s h Columbia c o a s t ? I t seems r e a s o n a b l e t o c o n c l u d e t h a t pods w i t h i n a c l a n a r e r e l a t e d s i n c e t h e r e a re c l e a r s i m i l a r i t i e s i n t h e i r c a l l r e p e r t o i r e s . However, I c o u l d i d e n t i f y no homologous c a l l s i n the t r a d i t i o n s of d i f f e r e n t c l a n s , and thus i t i s u n l i k e l y t h a t c l a n s have o r i g i n a t e d from a common a n c e s t r a l group, a t l e a s t i n the r e c e n t p a s t . A more r e a s o n a b l e h y p o t h e s i s i s t h a t each of the f o u r c a l l t r a d i t i o n s d e v e l o p e d i n d e p e n d e n t l y over l o n g p e r i o d s i n g e o g r a p h i c i s o l a t i o n . T h e i r o c c u r r e n c e on the B.C. c o a s t may be the r e s u l t of u n r e l a t e d f o u n d i n g e v e n t s . The fo u n d i n g pod of each l o c a l c l a n may have d i s p e r s e d from a d i s t a n t c o r e area and c o l o n i z e d an unoccupied r e g i o n a l o n g the c o a s t . A l t e r n a t i v e l y ' , c o l o n i z a t i o n may have i n v o l v e d a t r a n s i t i o n from a nomadic way of l i f e , such as t h a t of t r a n s i e n t whales ( P a r t I I I ) , t o a more s e d e n t a r y e x i s t e n c e t y p i c a l of r e s i d e n t pods. H i s t o r i c a l founder e f f e c t s a re c o n s i d e r e d i m p o r t a n t i n the o r i g i n and s p r e a d of-, human languages and d i a l e c t s ( F r i e d l a e n d e r e t a l . 1971; Spielman e t a l . 1974; T r u d g i l l 1983) and song t r a d i t i o n s i n b i r d s (Mundinger 1975, 1980; Payne 1981; T r a i n e r 1983). 222 Of the four resident k i l l e r whale clans in B.C., only the J-clan occupies an exclusive range. Its d i s t i n c t c a l l t r a d i t i o n may thus be maintained through geographic i s o l a t i o n from other clans. The A-, G- and R-clans of the northern resident community overlap in d i s t r i b u t i o n yet each maintains a unique c a l l t r a d i t i o n . Social or behavioural i s o l a t i n g mechanisms are probably important in preserving the i n t e g r i t y of these t r a d i t ions. Assuming pods in a clan are descended from a common founding group, d i a l e c t s within the clan's c a l l t r a d i t i o n probably developed l o c a l l y as the lineage evolved. Formation of new pods most l i k e l y involves the gradual s p l i t t i n g of old pods (Bigg 1982). Dialects in a c a l l t r a d i t i o n could thus be viewed as behavioural r e f l e c t i o n s of the common heritage of the clan's pods and the divergence that has occurred within the lineage. Several mechanisms of vocal change leading to d i a l e c t formation have been i d e n t i f i e d in birds and man (Lemon 1975; Slater and Ince 1979; Slater et a l . 1980; Mundinger 1980; Payne 1981; T r u d g i l l 1983). Those that could p o t e n t i a l l y have a role in the formation of k i l l e r whale d i a l e c t s include (1) c u l t u r a l d r i f t , (2) innovation and (3) c u l t u r a l d i f f u s i o n . Cultural d r i f t involves the appearance of random errors in vocal copying and the transmission of these changes across generations. Errors might accumulate as pods grow and s p l i t , r esulting in the complex group-specific modifications in c a l l structure evident within clans. D r i f t might result only in changes to established c a l l types in the clan. The creation of 223 new c a l l s in a pod's repertoire would require vocal innovation and subsequent imitation. Both of these forms of variation exist in d i a l e c t s within clans, and thus both d r i f t and innovation may be involved. The manner in which k i l l e r whales learn c a l l s has important implications for the development of d i a l e c t s . If young whales s e l e c t i v e l y learn only the c a l l s of their mother, c a l l divergence could begin among matrilines before a pod s p l i t s . If an individual's repertoire i s established early in l i f e and i s thereafter resistant to change, pod-specific c a l l patterns would be slow to evolve. If c a l l s change s l i g h t l y with each generation, old whales in the pod would have more archaic forms of c a l l s than juveniles. These old versions would eventually disappear as animals die. Newly innovated vocal patterns might spread quickly among younger animals in a pod but never be adopted by older whales. This was observed with certain c a l l s in Japanese monkeys (Green 1975b). Unfortunately, we cannot t e l l which of these learning mechanisms i s correct without intensive studies of the vocal patterns of individual whales. Certain c a l l s within a clan's t r a d i t i o n appear more susceptible to change than others, which would not be expected i f random d r i f t i s the primary mechanism involved. For example, the resting c a l l N3 i s produced in e s s e n t i a l l y the same manner by a l l 8 pods of the A-clan, yet most other shared c a l l s d i f f e r markedly. There are several other indications that some c a l l variations do not result from chance learning errors. As an example, A5-pod's versions of 5 of the 11 c a l l s shared by the 2 2 4 t h r e e A-pods have s t r o n g l y emphasized t e r m i n a l components, b o t h i n d u r a t i o n and frequency s h i f t s . In A1 and A4 pods, however, t h e s e c a l l s a l l have weakly d e v e l o p e d or n o n - e x i s t e n t t e r m i n a l p a r t s . Another example i s i n the convergence of s t r u c t u r e i n v e r s i o n s of c a l l s N1 and N8 e m i t t e d by H pod ( F i g . 49). These two c a l l s show no s t r u c t u r a l s i m i l a r i t y i n o t h e r A - c l a n r e p e r t o i r e s , y e t i n H pod they have both a c q u i r e d the same v e r y d i s t i n c t i v e sound q u a l i t y . In some c a s e s , the two c a l l s c o u l d o n l y be d i s t i n g u i s h e d by the c o n s i s t e n t a s s o c i a t i o n of c a l l N7 and N8. These o b s e r v a t i o n s suggest t h a t development of d i a l e c t s w i t h i n c a l l t r a d i t i o n s may be i n f l u e n c e d by unique b e h a v i o u r a l t r e n d s w i t h i n each group. Thus, v o c a l d i v e r g e n c e i n the t h r e e c l o s e l y - r e l a t e d A-pods, f o r example, may have been d i r e c t e d by a g e n e r a l i z e d p r e d i s p o s i t i o n towards s t r o n g c a l l endings i n A5 pod (or an a n c e s t r a l g r o u p ) , or towards reduced c a l l e ndings i n A l and A4 pods. Perhaps these t e n d e n c i e s can be a t t r i b u t e d t o t h e b e h a v i o u r a l i d i o s y n c r a c i e s of a s o c i a l l y - d o m i n a n t member i n each pod or l i n e a g e , p o s s i b l y a f o u n d i n g m a t r i a r c h . C u l t u r a l d i f f u s i o n can be an i m p o r t a n t source of v o c a l v a r i a t i o n i n b i r d s and humans. New sounds a r e i n t r o d u c e d i n t o a v o c a l t r a d i t i o n by immigrants and these sounds spr e a d i n t o t h e r e c i p i e n t p o p u l a t i o n ' s r e p e r t o i r e (Mundinger 1980; S l a t e r e t a l . 1980; Payne 1981). . D i f f u s i o n may a l s o r e s u l t from temporary c o n t a c t of d i f f e r e n t v o c a l t r a d i t i o n s , e s p e c i a l l y i n human p o p u l a t i o n s (Spielman et a l . 1974; T r u d g i l l 1983). There i s , however, no i n d i c a t i o n t h a t d i f f u s i o n i s i n v o l v e d i n the 225 Figure 49. Examples of c a l l types N1 and N8 given by H pod. These two c a l l types appear to have become s t r u c t u r a l l y modified in a similar manner in th i s pod's repertoire. 227 formation of c a l l d i a l e c t s in k i l l e r whales. No dispersal from or immigration into pods has been observed since monitoring of the B.C. k i l l e r whale population began in 1973 (Bigg 1982; pers. comm.). If transfer of individuals occurred between pods, i t would be expected that the di a l e c t systems within clans, as well as the acoustic i n t e g r i t y of the clan i t s e l f , might be broken down through c u l t u r a l d i f f u s i o n . Migrants would presumably introduce their own natal repertoire into the pod they j o i n , which would then have a blend of d i a l e c t s . It i s possible, however, that a transferring animal could switch i t s c a l l repertoire to that of i t s new group. This seems unlikely, however, because there i s a pod with a composite c a l l repertoire which may be a result of immigration. This single case involves 11 pod of the A-clan, which usually produces c a l l subtypes that are either unique to the group or shared with B pod. However, a small proportion of c a l l s recorded from the pod i s consistently comprised of subtypes t y p i c a l of H pod (Table IX). This suggests that an animal from H pod may have transferred to 11 and retained i t s natal repertoire. If so, i t i s probably a rare occurrence. The innovation of new c a l l types or structural d i f f e r e n t i a t i o n of shared c a l l s seems to occur without the use of any 'raw material' from other c a l l t r a d i t i o n s to which a pod is exposed. I t - i s clear that the animals can reproduce c a l l s of other t r a d i t i o n s since they do so on rare occasions (Part I ) . However, no c a l l transfer has occurred among the four c a l l t r a d i t i o n s in the resident population. It i s apparent that 228 there is a strong conservatism in the process of vocal divergence which prevents d i f f u s i o n from unrelated di a l e c t s and serves to preserve the distinctiveness of each t r a d i t i o n . F i n a l l y , vocal variation in k i l l e r whales also results from the loss of c a l l s from group-specific repertoires. An example of a gradual loss of a c a l l type can be seen in J-pod's use of S14. This signal was very common in the early 1960's, both in the c a l l i n g of captive whales and in f i e l d recordings. In recent years, however, the c a l l has been heard very rarely. S i m i l a r l y , c a l l N49 comprised 8.1% of the signals recorded from an R-clan pod in 1964, but did not occur in R-clan samples from 1973 or 1981-83. There are numerous cases of c a l l s apparently being lost from the repertoires of certain pods in a clan. Pod A5, for example, is the only one of the eight A-clan pods that does not have some version of c a l l N1. C a l l N5 has apparently been lost from the repertoires of pods C and D, while i t remains a common component in the repertoires of the rest of the clan. K i l l e r Whale Dialects; Byproducts or Adaptations? Perhaps the most important questions to be considered concern the potential ultimate factors responsible for the development of dia l e c t s in k i l l e r whales. Do c a l l variations within a clan represent byproducts of the processes of vocal learning - and population evolution, and thus have no adaptive significance? Or, can di a l e c t s be viewed as active modifications and, i f so, what might be their selective value? Current evidence is i n s u f f i c i e n t to confidently answer such 229 questions, but i t is possible to offer some speculations. The simplest interpretation cf group-specific d i a l e c t s i s that they represent non-functional c u l t u r a l d r i f t . Changes in c a l l t r a d i t i o n s may result from transcription errors during vocal learning or from behavioural idiosyncracies of ind i v i d u a l whales, which are transmitted to other animals in the pod. These changes may be neither advantageous or disadvantageous and have simply accumulated over generations. Group-specific modifications are maintained in the pod as a result of strong s o c i a l bonding and the lack of dis p e r s a l . An alternative hypothesis i s that d i a l e c t s function as indicators of kinship, and thus could be considered acti ve modifications. There are several potential advantages to such a system. F i r s t , discrete c a l l s most l i k e l y serve as contact signals during periods of dispersion of a pod. The c a l l s probably convey information on the vocalizer's i d e n t i t y , location, and state of arousal (Part I ) . With the addition of group-identity information, the c a l l s would have an enhanced usefulness in maintaining group cohesion at times when several pods are together in the same v i c i n i t y (Ford and Fisher 1983). Interestingly, a similar function was proposed in 1962 by Andrew to account for vocal mimicry in dolphins. In developing his argument, Andrew (1962) suggested that mimicry as seen in dolphins may have allowed the development of group-specific patterns of vocalization in early man. These patterns would have been important in maintaining the i n t e g r i t y of the group, es p e c i a l l y in a hunting society where group members were often 230 subdivided when foraging. In addition, the capacity for vocal learning may also have led to large repertoires of sounds to provide a better "match" against external sounds. A second potential function of a kin-recognition system in k i l l e r whales may be inbreeding avoidance. Whales in the study area may be especially susceptible to inbreeding because of the apparent lack of dispersal of individuals from the natal group. As Moore and A l i (1984) point out, behavioural inbreeding avoidance may evolve where dispersal patterns result in a high risk of incest. It is unknown whether breeding occurs within or between pods since matings have not been observed. For one pod in the northern community, 111, breeding i s c l e a r l y exogamous since the group has no mature males, yet females in the pod give b i r t h regularly. Resident pods might interbreed with any other pods with which they associate. If individuals can assess their relatedness by d i a l e c t , they may be able to choose mating partners who are optimally related, thus avoiding both excessive inbreeding and outbreeding. Depending on community demography, whales may breed outside the pod but within the clan, or outside the clan. Treisman (1978) has proposed that d i a l e c t variations in bird song may function in a similar way as a mechanism for kin recognition. A song d i a l e c t would serve as a "family badge" (Krebs and Kroodsma 1980) which r e f l e c t s the degree of relatedness of kin in a more v e r s a t i l e and f l e x i b l e manner than would be possible with a genetic marker. Repertoires of several varying songs would allow the encoding of more detailed 231 genealogical information than a single song type. Kin-recognition systems appear to be common in vertebrates (Moore and A l i 1984; Beecher 1982). Wild vervet monkeys (Cercopithicus aethiops), for example, can recognize individuals within their own group and in neighbouring groups on the basis of d i s t i n c t i v e features in each animal's c a l l s (Cheney and Seyfarth 1982). There is evidence that, within groups, vervets can c l a s s i f y individuals according to the maternal subgroups to which they belong. Whether they are able to assess relatedness across groups by t h i s means is unknown. Vocal Variation and Population Structure Examination of the acoustic associations among resident k i l l e r whale pods can provide useful information on the structure of the population. If each clan, as defined by i t s d i s t i n c t i v e c a l l t r a d i t i o n , represents an independent lineage., i t i s probable that each has become genetically d i f f e r e n t i a t e d to some degree. It may also be that each pod is genetically d i s t i n c t from others in i t s clan, and that vocal d i a l e c t s within the t r a d i t i o n r e f l e c t t h i s d i f f e r e n t i a t i o n . In s o c i a l primates, new groups often form by d i v i s i o n of formerly cohesive larger groups along l i n e s of maternal relatedness (Nash 1976; Chepko-Sade and Sade 1979; O l i v i e r et a l . 1981). This i s probably also the manner of pod formation in k i l l e r whales (Bigg 1982). Because matrilines in primate groups are genetically d i s t i n c t , such non-random s p l i t t i n g can, under certain demographic conditions, result in large variations in 232 gene f r e q u e n c i e s between daughter groups ( B u e t t n e r - J a n u s c h et a l . 1983; Cheney and S e y f a r t h 1983; M e l n i c k and K i d d 1983; M e l n i c k et a l . 1984). S i m i l a r g e n e t i c d i v e r g e n c e , or ' l i n e a l e f f e c t s ' , o c cur among v i l l a g e s of American I n d i a n t r i b e s t h a t form by m a t r i l i n e a l d i v i s i o n (Neel and Ward 1970). Perhaps the b e s t documented l i n e a l e f f e c t s e x i s t among the Yananamo I n d i a n s of South America (Neel 1978). The Yananamo t r i b e i s g e n e t i c a l l y and c u l t u r a l l y d i s t i n c t from o t h e r South American t r i b e s , and v i l l a g e s w i t h i n the t r i b e show marked g e n e t i c d i v e r g e n c e from each o t h e r . Of s i g n i f i c a n c e i n the c o n t e x t of the p r e s e n t study i s t h a t the v i l l a g e s have a l s o become d i f f e r e n t i a t e d l i n g u i s t i c a l l y i n t o a number of d i a l e c t g roups. P a t t e r n s of l i n g u i s t i c d i v e r g e n c e c o r r e s p o n d c l o s e l y t o t hose of g e n e t i c m i c r o d i f f e r e n t i a t i o n . Those v i l l a g e s w i t h s i m i l a r d i a l e c t s tend a l s o t o be the most c l o s e l y r e l a t e d g e n e t i c a l l y (Spielman et a l . 1974). The degree of g e n e t i c d i f f e r e n t i a t i o n t h a t might e x i s t between pods depends on the e x t e n t of l i n e a l e f f e c t s r e s u l t i n g from pod f i s s i o n and whether mating i s endogamous w i t h i n the pod, c l a n , or community. I t does seem r e a s o n a b l e , however, t h a t c a l l t r a d i t i o n s and d i a l e c t s r e f l e c t the p h y l o g e n e t i c h i s t o r y of the r e s i d e n t p o p u l a t i o n i n B.C. I t i s t h e r e f o r e i n t e r e s t i n g t h a t the p a t t e r n s of s o c i a l a s s o c i a t i o n and d i s t r i b u t i o n o b s e r v e d among r e s i d e n t pods has, i n most c a s e s , g i v e n l i t t l e i n d i c a t i o n of t h i s u n d e r l y i n g demographic s t r u c t u r e w i t h i n the p o p u l a t i o n . 233 Time Depth of V o c a l P i f f e r e n t i a t i o n A l t h o u g h c a l l t r a d i t i o n s and d i a l e c t s may p r o v i d e an o u t l i n e of the e v o l u t i o n a r y h i s t o r y of r e s i d e n t k i l l e r whales i n B.C., a s s i g n i n g a time s c a l e t o the p r o c e s s of p o p u l a t i o n change and v o c a l d i f f e r e n t i a t i o n i s d i f f i c u l t . E x a m i n a t i o n of h i s t o r i c a l k i l l e r whale r e c o r d i n g s r e v e a l e d few d i f f e r e n c e s i n r e s i d e n t d i a l e c t s between as e a r l y as 1958 and 1983. Without an a c c u r a t e measure of the r a t e of v o c a l change, i t i s not p o s s i b l e t o a p p l y t e c h n i q u e s used i n e s t i m a t i n g the time depth of l i n g u i s t i c d i v e r g e n c e ( e . g . , Spielman e t a l . 1974; Payne e t a l . 1981). However, i t i s p o s s i b l e t o make some rough e s t i m a t e s . The complete l a c k of homologous c a l l s among the fo u r r e s i d e n t c l a n s s u g g e s t s t h a t each c a l l t r a d i t i o n developed i n d e p e n d e n t l y over l o n g p e r i o d s i n i s o l a t i o n and came t o g e t h e r s u b s e q u e n t l y on the B.C. c o a s t . T h i s p e r i o d of development c o u l d i n v o l v e hundreds of y e a r s . Each c l a n may have become e s t a b l i s h e d on the c o a s t a t w i d e l y spaced i n t e r v a l s . The A - c l a n has d i f f e r e n t i a t e d i n t o e i g h t pods w i t h d i v e r g e n t d i a l e c t p a t t e r n s , and t h e r e f o r e , might have had a l o n g p e r i o d of l o c a l occupancy. The R - c l a n , however, c o n s i s t s of o n l y two a c o u s t i c a l l y - s i m i l a r groups and hence may be r e l a t i v e l y r e c e n t c o l o n i z e r s . U n f o r t u n a t e l y , s e v e r a l p o t e n t i a l f a c t o r s , such as d i f f e r e n t i a l r e p r o d u c t i v e s u c c e s s of c l a n s and founding-group s i z e s , c o m p l i c a t e t h e s e s p e c u l a t i o n s . Because of the e x t r e m e l y slow growth r a t e of r e s i d e n t pods and the l o n g e v i t y of i n d i v i d u a l s , i t may be decades b e f o r e a pod b e g i n s t o s p l i t , a g r a d u a l p r o c e s s which i t s e l f may ta k e many 234 y e a r s t o c o m p l e t e . As an example, when f i r s t i d e n t i f i e d i n 1973, pods A1, A4 and A5 were c l o s e l y a s s o c i a t e d but c l e a r l y d i s c r e t e s o c i a l u n i t s . A f t e r 10 y e a r s , they s t i l l spend most of t h e i r time t r a v e l l i n g t o g e t h e r . The c a l l r e p e r t o i r e s of t h e t h r e e pods have d i v e r g e d t o o n l y a minor e x t e n t compared t o the l a r g e d i f f e r e n c e s apparent i n o t h e r A - c l a n d i a l e c t s . I t i s p o s s i b l e t o draw comparisons between k i l l e r whale d i a l e c t s and t h o s e of o t h e r a n i m a l groups. However, the s e must be i n t e r p r e t e d w i t h c a u t i o n because of the d i v e r s i t y of s o c i a l s t r u c t u r e , f u n c t i o n of a c o u s t i c s i g n a l s , and a d a p t i v e s i g n i f i c a n c e of the d i a l e c t s . Long-term s t u d i e s of song d i a l e c t s i n s e v e r a l b i r d s p e c i e s have documented the p e r s i s t e n c e of l o c a l song t y p e s a c r o s s s e v e r a l g e n e r a t i o n s . Payne et a l . (1981) o b s e r v e d some song t y p e s i n a p o p u l a t i o n of i n d i g o b u n t i n g s ( P a s s e r i n a cyanea) t o have s u r v i v e d i n r e c o g n i z a b l e form over 15 y e a r s . D i a l e c t s of white-crowned sparrows ( Z o n o t r i c h i a l e u c o p h r y s ) a t one l o c a t i o n were found by T r a i n e r (1983) t o have r e t a i n e d the same b a s i c s t r u c t u r e over 18 y e a r s . There may be a b e t t e r a n a l o g y between the r a t e s of d i a l e c t d i v e r g e n c e i n c e r t a i n human s o c i e t i e s and k i l l e r whales because of the s i m i l a r l o n g e v i t y of i n d i v i d u a l s . Spielman e t a l . (1974) e s t i m a t e from s h a r e d cognates t h a t the Yananamo language group has e v o l v e d i n i s o l a t i o n from o t h e r r e l a t e d South American I n d i a n languages f o r 1500-3000 y e a r s . W i t h i n the Yananamo t r i b e , the maximum d u r a t i o n of s e p a r a t i o n between d i s t a n t l y r e l a t e d v i l l a g e s i s e s t i m a t e d t o be 600-1200 y e a r s , and the minimum f o r c l o s e l y r e l a t e d v i l l a g e s i s 75-200 y e a r s . 235 While i t i s doubtful that the retention rate of k i l l e r whale c a l l s i s the same for words within human languages, t h i s comparison does serve to emphasize that c u l t u r a l traditions may persist for extremely long periods in mammals. Continued sampling of resident k i l l e r whale vocalization in future years w i l l hopefully result in a precise measure of the rate of dia l e c t divergence. With th i s i t w i l l be possible to reconstruct the d e t a i l s and timing of growth and so c i a l evolution in the population with better accuracy. 236 PART III VOCAL BEHAVIOUR AND DIALECTS IN TRANSIENT KILLER WHALES 237 INTRODUCTION A ten-year study of k i l l e r whales (Oreinus orca) in B r i t i s h Columbia based on a photographic technique for ide n t i f y i n g individual whales has documented the abundance, d i s t r i b u t i o n and natural history of the species in the region (Bigg et a l . .1976; Bigg 1982). K i l l e r whales were found to l i v e in stable s o c i a l groups, or pods, which probably consist of kin-related animals. Two types of pods inhabit B.C. coastal waters (Bigg 1982). 'Resident' pods occur in r e l a t i v e l y predictable locations during the summer months and probably remain in the area year round. The resident population is divided into two geographically-segregated communities. Pods within each community mix and travel together, but the two communities do not interact. 'Transient' pods are uncommon, and occur sporadically in unpredictable locations. They range throughout both resident communities, but do not associate with residents. Transient and resident whales d i f f e r in morphology, s o c i a l structure, diet, and behaviour. Bigg's photo-identification technique was also used in an examination of the underwater vocal behaviour of known k i l l e r -whale pods in the same area. Resident pods were found to have repertoires of s t r u c t u r a l l y - d i s c r e t e c a l l s which vary from pod to pod (Ford and Fisher 1982, 1983). The 16 resident pods in B.C. can be divided into four 'clans' based on d i a l e c t s . Each clan constitutes a d i s t i n c t c a l l t r a d i t i o n made up of a set of pods which share a portion of the i r c a l l repertoire. Three of the four resident clans occur in one community and pods from 238 these c l a n s mix on a r e g u l a r b a s i s ( P a r t I I ) . T h i s c h a p t e r examines the underwater sounds of t r a n s i e n t k i l l e r whales. T r a n s i e n t ' s v o c a l b e h a v i o u r i s compared t o t h a t of r e s i d e n t whales and p o s s i b l e f u n c t i o n s are d i s c u s s e d . D i a l e c t s of t r a n s i e n t pods a r e i n t e r p r e t e d i n terms of s o c i a l a s s o c i a t i o n s and g e o g r a p h i c a l d i s t r i b u t i o n . 239 MATERIALS AND METHODS j _ . F i e l d O b s e r v a t i o n s and R e c o r d i n g T r a n s i e n t k i l l e r whales were encountered on 15 o c c a s i o n s d u r i n g 1979-83 i n the waters s u r r o u n d i n g Vancouver I s l a n d , B.C. O b s e r v a t i o n s and r e c o r d i n g s were o b t a i n e d i n the manner d e s c r i b e d i n P a r t s I and I I . Pod i d e n t i t i e s were determined from photographs taken of the d o r s a l f i n and s a d d l e p a t c h of each i n d i v i d u a l o b s e r v e d . T h i s t e c h n i q u e i s d e s c r i b e d i n d e t a i l i n P a r t I I and B i g g (1982). P h o t o - i d e n t i f i c a t i o n s were made by M. B i g g . Underwater r e c o r d i n g s were made u s i n g equipment and pro c e d u r e s d e t a i l e d i n P a r t I I . A d d i t i o n a l t a p e s of t r a n s i e n t whale v o c a l i z a t i o n s were o b t a i n e d from s e v e r a l o t h e r i n d i v i d u a l s (Table X V I ) . These were made on a v a r i e t y of r e c o r d i n g systems. 2. Sound A n a l y s i s Recorded v o c a l i z a t i o n s were a n a l y z e d as d e s c r i b e d i n P a r t I I . As w i t h r e s i d e n t k i l l e r w h a l e s , the underwater s i g n a l s of t r a n s i e n t whales c o n s i s t p r i m a r i l y of r e p e t i t i o u s c a l l s which can be o r g a n i z e d i n t o d i s c r e t e s t r u c t u r a l c a t e g o r i e s . C a l l t y p e s were d e t e r m i n e d i n i t i a l l y by e a r , and then c o n f i r m e d w i t h e x a m i n a t i o n of spectrograms made on a Kay E l e m e t r i c s 7029A spectrum a n a l y z e r . Each c a l l t y pe i s i d e n t i f i e d w i t h the l e t t e r 'T', i n d i c a t i n g t h a t i t was g i v e n by a t r a n s i e n t pod, and a number. 240 RESULTS 1 * Characteristics of_ Transient Whales Most of the following information on the population dynamics and s o c i a l organization of transient whales results from the work of Bigg (1982, pers. comm.). Seventeen transient pods containing 55 individuals have been i d e n t i f i e d on the coast of B r i t i s h Columbia. These d i f f e r from resident pods in many respects. The size and composition of transient pods are l i s t e d in Table XV. Pod sizes range from 1-8, with an average of 3.24 individuals per pod. In contrast, resident pods average 13.4 members (range 4 - 50). Unlike resident pods, transients do not appear to have any well-defined range or foraging routine. They are seen infrequently at irregular times of the year, and in unpredictable locations. While foraging, members of transient pods tend to stay together and t r a v e l close to shore. Residents, on the other hand, scatter over wide areas while foraging. Transients usually swim deeply into bays, blind channels, and through dense kelp beds. They change direction frequently, and tend to dive for long periods. In a sequence of 18 dives by a foraging transient pod, dive times averaged 5.8 min (SD = 1.72 min) within a range of 2.25 - 9.0 min. Dives of resident whales are rarely over 3 min in duration during foraging. Transients may spend several hours at a single feeding location, and they may be seen within the same area of 10-20 km of coastline for several days. However, one transient 241 T a b l e XV. S i z e and c o m p o s i t i o n o f t r a n s i e n t pods i d e n t i f i e d o f f Vancouver I s l a n d . Pod s i z e s c o n s i d e r e d e x a c t , e x c e p t those marked by *, which are p r o b a b l y a c c u r a t e t o w i t h i n one i n d i v i d u a l . Data from M. B i g g (1982 and p e r s . comm.). Pod S i z e No. o f b u l l s No. o f cows NO. Of j u v e n i l e s No. o f o f c a l v e s E F M N 02 04 P Q S I S8 T U V I V10 X Y Z 5* 1 3 1 3 2 2 5 4 1 4* 4 2 8 5 3 2 1+ 1 ? ? 0 1 0 3 0 0 2 ? 0 1 0 0 242 pod was observed t o t r a v e l a minimum s t r a i g h t - l i n e d i s t a n c e of about 600 km over 6 days ( B i g g et a l . 1976). E v i d e n c e from stomach c o n t e n t s of s t r a n d e d a n i m a l s and f i e l d o b s e r v a t i o n s i n d i c a t e t h a t marine mammals a r e a major component of the d i e t of t r a n s i e n t k i l l e r w hales. S p e c i e s taken by t r a n s i e n t s i n l o c a l waters a r e m a i n l y harbour s e a l s (Phoca v i t u l i n a ) , S t e l l e r sea l i o n s (Eumetopias j u b a t u s ) , harbour p o r p o i s e (Phocoena phocoena) and e l e p h a n t s e a l s (Mirounga a n g u s t i r o s t r i s ) . R e s i d e n t whales, i n c o n t r a s t , appear t o f e e d p r e d o m i n a n t l y on salmon (Oncorhynchus spp.) and o t h e r f i s h s p e c i e s i n the study a r e a ( P a r t I I ) . The 17 t r a n s i e n t pods form a community s i m i l a r t o but d i s t i n c t from the two r e s i d e n t communities. T r a n s i e n t pods f r e q u e n t l y j o i n and t r a v e l w i t h o t h e r t r a n s i e n t s i n the community, as do pods w i t h i n each of the two r e s i d e n t communities ( P a r t I I ) . T r a n s i e n t s t r a v e l t h r o u g h o u t both the n o r t h e r n - and s o u t h e r n - r e s i d e n t community r a n g e s , but do not a s s o c i a t e w i t h r e s i d e n t pods. T r a n s i e n t pods were t w i c e observed t o meet r e s i d e n t s . On both o c c a s i o n s , the two t y p e s of whales c o n t i n u e d on w i t h o u t m i x i n g or showing any o b s e r v a b l e r e a c t i o n . The range of l o c a l t r a n s i e n t pods i s unknown, but i t i n c l u d e s . a t l e a s t the n o r t h e r n and s o u t h e r n r e s i d e n t communities. One group, V10, has been s i g h t e d o f f n o r t h e a s t e r n Vancouver I s l a n d and i n F r e d r i c k Sound, S o u t h e a s t A l a s k a , about 900 km t o the n o r t h (G. E l l i s and D. McSweeney, p e r s , comm.). T r a n s i e n t whales a l s o d i f f e r from r e s i d e n t s i n morphology. A h i g h p r o p o r t i o n of t r a n s i e n t cows have d o r s a l f i n s which t a p e r 243 to a sharp point, unlike the rounded tip s on most resident cows. The shape of the leading edge of the f i n also d i f f e r s s l i g h t l y , and the dorsal saddle patch tends to be larger and extends further a n t e r i o r l y in transients. 2. Acoustic Behaviour Transient whales are very quiet compared to residents. A t o t a l of 13 transient pods was encountered on 15 occasions in the waters around Vancouver Island. The animals were observed and monitored a c o u s t i c a l l y over a t o t a l of 45.4 h, for a mean of 3.03 h per encounter. Sounds were heard during only 5 of these 15 encounters, and usually for only a few minutes on each occasion. Transients tend to be completely s i l e n t while foraging, which is their most common a c t i v i t y . This includes echolocation-type c l i c k s , which, in contrast, are heard throughout foraging episodes in resident pods. Occasionally, foraging transient whales emit a low-level c a l l , T1, which appears to be a c h a r a c t e r i s t i c signal throughout the community. Several examples of c a l l T1 as rendered by d i f f e r e n t pods are shown in Figure 50. This signal was the only one recorded during a meeting between two transient pods, Y and Q. The meeting was associated with much apparent excitement, including a variety of aerobatics and speed swimming, yet the rate of c a l l i n g and c a l l d i v e r s i t y were much lower than in similar contexts in resident pods. Loud, discrete c a l l s t y p i c a l of resident k i l l e r whales have 244 Figure 50. Sample spectrograms of c a l l type T1. Examples shown for pods M, X and Y, recorded in B.C., and SEA pod recorded in southeast Alaska. 245 r o T ~ 1 500 ms 246 been r e c o r d e d on o n l y a few o c c a s i o n s . The b e s t sample of c a l l s was o b t a i n e d from pod X, a group of f i v e whales, as the a n i m a l s m i l l e d s l o w l y a t the s u r f a c e f o r a p p r o x i m a t e l y 2 h. They were n e a r l y c o n t i n u o u s l y v o c a l throughout t h i s p e r i o d , e m i t t i n g a t o t a l of 6 d i s c r e t e c a l l t y p e s . Sample spectrograms of these s i g n a l s are i l l u s t r a t e d i n F i g u r e 51, and t h e i r f r e q u e n c y of o c c u r r e n c e i n F i g u r e 52. On a n o t h e r o c c a s i o n , Y pod, c o n s i s t i n g of a b u l l , cow, and j u v e n i l e , was observed f o r a p e r i o d of 4 h w h i l e f o r a g i n g . The a n i m a l s were c o n s i s t e n t l y s i l e n t , except f o r an i n t e r v a l of 1.5 min as the pod s e p a r a t e d and approached a r e e f where harbour s e a l s were h a u l e d o u t . A . t o t a l of 6 c a l l s , b e l o n g i n g t o 3 c a l l t y p e s , were e m i t t e d by the j u v e n i l e d u r i n g t h i s v o c a l p e r i o d . S e v e r a l o t h e r o b s e r v a t i o n s of pods s p l i t t i n g t e m p o r a r i l y and a p p r o a c h i n g s e a l h a u l - o u t s were not accompanied by v o c a l i z a t i o n . A l t h o u g h t r a n s i e n t s g e n e r a l l y f o r a g e i n s i l e n c e , they seem t o become v o c a l w h i l e i n the p r o c e s s of c a p t u r i n g p r e y . T h i s was observed on a l l t h r e e o c c a s i o n s t h a t t r a n s i e n t pods were mo n i t o r e d a c o u s t i c a l l y w h i l e making a k i l l or f e e d i n g (G. E l l i s , D. McSweeney, R. Osborne, p e r s . comms.). G r o u p - r e s t i n g b e h a v i o u r s i m i l a r t o t h a t of r e s i d e n t s was seen o n l y once i n t r a n s i e n t s . Two pods, Y and Q, were obser v e d t o g r o u p - r e s t t o g e t h e r i n a s m a l l bay f o r 1.5 h. The pods s t a y e d 100-200 m a p a r t and each d i v e d i n d e p e n d e n t l y f o r 5-7 min a t a t i m e . The a n i m a l s remained s i l e n t t hroughout the r e s t i n g p e r i o d . 247 3_. D i a l e c t s C a l l t y p e s produced by t r a n s i e n t pods r e c o r d e d i n B r i t i s h C olumbia, C a l i f o r n i a , and s o u t h e a s t A l a s k a waters are l i s t e d i n T a b l e XVI. These c a l l t y p e s a r e u n l i k e t h o s e g i v e n by any r e s i d e n t pod . ( P a r t I I ) . A t o t a l of 8 i d e n t i f i e d pods and 2 u n i d e n t i f i e d groups were i n v o l v e d i n t h e s e e n c o u n t e r s . The r e c o r d i n g of 04 pod was o b t a i n e d w h i l e the group was h e l d t e m p o r a r i l y i n a c a p t i v e pen i n Budd I n l e t , Puget Sound, Washington, i n 1976. T h i s pod was e n c o u n t e r e d i n 1982 o f f s o u t h e r n Vancouver I s l a n d , but no sounds were r e c o r d e d . The C a l i f o r n i a tape was made i n the presence of 3 whales, a b u l l , cow and j u v e n i l e , who approached the r e c o r d i n g v e s s e l f o l l o w i n g underwater p l a y b a c k of r e c o r d e d t r a n s i e n t v o c a l i z a t i o n s (X pod, r e c o r d e d i n B.C.). Photographs of t h e s e a n i m a l s i n d i c a t e t h a t they a r e a d i f f e r e n t pod than any p r e v i o u s l y i d e n t i f i e d i n B.C. w a t e r s . The two e n c o u n t e r s i n s o u t h e a s t A l a s k a i n v o l v e d a pod of 5 whales, t e n t a t i v e l y i d e n t i f i e d as 'SEA', which has not been observed i n B.C. w a t e r s . On one of the two e n c o u n t e r s , V10 pod, a group which was p r e v i o u s l y i d e n t i f i e d o f f n o r t h e r n Vancouver I s l a n d , was t r a v e l l i n g w i t h SEA pod. A l l t r a n s i e n t pods r e c o r d e d share a t l e a s t one c a l l t y p e , T1. As d e s c r i b e d above, i t i s a r a t h e r q u i e t c a l l t h a t i s g i v e n i n o c c a s i o n a l bouts d u r i n g f o r a g i n g e p i s o d e s . T1 was the o n l y c a l l r e c o r d e d d u r i n g 3 of the 10 e n c o u n t e r s . Seven o t h e r c a l l s , T2 t o T8, were i d e n t i f i e d on o t h e r e n c o u n t e r s . Four of t h e s e , T2, T3, T5 and T6, were produced o n l y by X pod ( F i g u r e 51). 2 4 8 Table XVI. D i s c r e t e c a l l types recorded from t r a n s i e n t pods. Pod Location Date Source * T l T2 T3 T4 T5 T6 T7 T8 04 Puget Sound, WA 10 Mar 1976 R.O. X X X M S . Vancouver Is. 15 Oct 1979 G.E. X ? S. Vancouver i s . 28 Sep 1979 R.O. X X X S8, X N . Vancouver i s . 09 Aug 1980 J.F. X X N . Vancouver IS. 13 Aug 1980 J.F. X X X X X X Y S. Vancouver IS. 09 Sep 1980 J.F. X X X Q» V S. Vancouver IS. 13 Sep 1980 J.F. X ? Soberanes Pt ., CA 16 Jan 1983 CM. X X X X SEA, V10 S.E. Alaska 13 Aug 1983 D . M C S . X X X SEA S.E. Alaska 31 Aug 1983 D . M C S . X X X * Sources: G. E. = G. E l l i s ; West Coast whale Research Foundation J . F. = J . Ford C. M. = C Malme; B o l t , Beranek and Newman, Inc. D. McS. = D. McSweeney; independent researcher R. 0. = R. Osborne; Moclips C e t o l o g i c a l Society 250 Figure 51. Spectrograms of X-pod c a l l s T2, T3, T4, T5, and 251 252 Figure 52. Frequency d i s t r i b u t i o n of c a l l s produced by X pod. 253 X Pod n= 401 calls S Z LU o LU DC Z LU O DC LU CL 30 -, 20 A 10 H T1 T2 T3 T4 T6 17 C A L L T Y P E 254 C a l l s T7 and T8 were both r e c o r d e d on 5 o c c a s i o n s i n v o l v i n g a t l e a s t 4 d i f f e r e n t pods l o c a t e d i n C a l i f o r n i a , B.C., and s o u t h e a s t A l a s k a . The minimum d i s t a n c e between the C a l i f o r n i a and A l a s k a l o c a t i o n s i s about 3700 km. Examples of t h e two c a l l t y p e s r e c o r d e d from these groups a r e shown i n F i g u r e 53. Some d i f f e r e n c e s i n f i n e s t r u c t u r e can be seen, but u n f o r t u n a t e l y t h e r e a r e inadequate samples t o determine whether these r e p r e s e n t g r o u p - s p e c i f i c v a r i a t i o n s . The community of t r a n s i e n t pods on the west c o a s t of N o r t h America t h e r e f o r e may be a s i n g l e a c o u s t i c a s s o c i a t i o n e q u i v a l e n t t o the c l a n s w i t h i n r e s i d e n t communities ( P a r t I I ) . As i n r e s i d e n t c l a n s , t h e r e i s some c a l l s h a r i n g among a l l member pods, y e t c e r t a i n pods or s e t s of pods appear t o produce c a l l s which a r e not used by a l l i n the c l a n . 255 F i g u r e 53. Spectrograms of t r a n s i e n t pod c a l l s T7 and T8. Note d i a g n o s t i c narrowband component between 5 and 6 kHz a t the s t a r t of T7 c a l l s . 2 5 6 257 DISCUSSION Transient k i l l e r whales d i f f e r from residents in numerous ways. Their s i g n i f i c a n t l y smaller pod sizes suggest that transients have a d i f f e r e n t s o c i a l system than residents. Transients range more widely than residents, and have no well-defined or predictable d i s t r i b u t i o n at any time of the year. Transients form a community of associating pods which i s sympatric with resident communities, but the two types of whales appear not to interact s o c i a l l y when they meet. Transients hunt in small groups for marine mammal prey, while larger resident pods feed primarily on f i s h . Transient and resident k i l l e r whales also d i f f e r s t r i k i n g l y in acoustic behaviour. Residents tend to vocalize frequently while foraging, using an array of discrete s o c i a l signals as well as echolocation c l i c k s . Transients, on the other hand, generally forage in silence, apparently without echolocation. Many aspects of the foraging behaviour of transients suggest that they hunt oppor t u n i s t i c a l l y , relying on stealth to surprise and capture prey. They tend to dive for long periods and surface in unpredictable places, especially when around reefs and i s l e t s where seals are hauled out. A surprise strategy would seemingly be most e f f e c t i v e i f the whales hunted in silence, since seals and other marine mammals have good underwater hearing and may learn to avoid approaching whales. The lack of echolocation signals indicates that the whales may locate their prey v i s u a l l y or through passive l i s t e n i n g . This strategy may only be e f f e c t i v e when hunting in small groups, 258 since larger pods would require the exchange of c a l l s to coordinate movements. Presumably, large group size and high rates of vocalization do not negatively affect and may even enhance the foraging success of resident pods when feeding on f ish. A l l transient pods recorded to date are related a c o u s t i c a l l y and, using the d e f i n i t i o n s in Part II, may tentatively be regarded as a single 'clan' with a d i s t i n c t c a l l t r a d i t i o n . Within the t r a d i t i o n are c a l l d i a l e c t s exclusive to subsets of pods. The range of the transient clan i s large, spanning at least 3700 km of coastline, and overlaps geographically with the four resident clans studied here. The processes of pod formation and d i a l e c t development in transients may be similar to those proposed for residents (Part I I ) . The transient clan may represent a single phylogenetic lineage composed of related pods which have originated from a common ancestral group. Their shared c a l l t r a d i t i o n i s a r e f l e c t i o n of t h i s unique evolutionary history and probable genetic d i f f e r e n t i a t i o n from other lineages. The social i s o l a t i o n of transients and residents and morphological differences between the two also suggest that transients comprise a genetically d i s t i n c t population. Transients have apparently become adapted to a marine-mammal hunting existence which involves small group sizes, a nomadic d i s t r i b u t i o n and s i l e n t foraging. Residents, on the other hand, feed primarily on salmon, and their s o c i a l structure, d i s t r i b u t i o n and behaviour may be adaptations to a l i f e style dependent upon this 259 r e s o u r c e . I n t r a s p e c i f i c v a r i a t i o n i n s o c i a l s t r u c t u r e and f o r a g i n g has been r e p o r t e d i n o t h e r mammals (see review by L o t t 1984). Such v a r i a t i o n s may be c o n s i s t e n t f o r s e v e r a l g e n e r a t i o n s , but g i v e n a change i n prey abundance or t e r r i t o r y a v a i l a b i l i t y , a n i m a l s can s w i t c h from one s t r a t e g y t o a n o t h e r . Whether t r a n s i e n t s a r e a b l e t o s w i t c h t o a r e s i d e n t - t y p e of l i v i n g , or v i c e v e r s a , i s unknown. However, the a c o u s t i c , b e h a v i o u r a l , and m o r p h o l o g i c a l d i f f e r e n c e s between the two t y p e s of whales suggest a l o n g p e r i o d of s e g r e g a t i o n and d i v e r g e n c e . 2 6 0 GENERAL SUMMARY AND CONCLUSIONS T h i s study examines the p a t t e r n s of underwater v o c a l communication of k i l l e r whales i n B r i t i s h Columbia c o a s t a l w a t e r s . The p r i m a r y o b j e c t i v e of the study was t o g a i n a b e t t e r u n d e r s t a n d i n g of t h i s i m p o r t a n t a s p e c t of the a n i m a l s ' b e h a v i o u r and i t s r o l e i n the maintenance of s o c i a l s t r u c t u r e . The f o l l o w i n g summarizes the p r i n c i p a l f i n d i n g s d e s c r i b e d i n t h i s t h e s i s . The underwater sounds of 16 ' r e s i d e n t ' and 6 ' t r a n s i e n t ' k i l l e r whale pods were r e c o r d e d i n the waters s u r r o u n d i n g Vancouver I s l a n d d u r i n g 1978-83. H i s t o r i c a l f i e l d r e c o r d i n g s made i n the same area d u r i n g 1958-76, and s e v e r a l r e c o r d i n g s of c a p t i v e whales taken from l o c a l waters were a l s o examined. Three g e n e r a l c a t e g o r i e s of s o c i a l s i g n a l s were i d e n t i f i e d : (1) r e p e t i t i o u s , p u l s e d c a l l s which can be o r g a n i z e d i n t o d i s c r e t e c a t e g o r i e s , (2) v a r i a b l e p u l s e d sounds which are not r e p e a t e d and thus cannot be c l a s s i f i e d i n t o c a l l t y p e s , and (3) narrowband w h i s t l e s . In r e s i d e n t pods, the f i r s t sound c a t e g o r y , d i s c r e t e c a l l s , dominates v o c a l exchanges i n most c o n t e x t s . However, the fr e q u e n c y of use of d i s c r e t e c a l l s , v a r i a b l e c a l l s and w h i s t l e s , as w e l l as a b e r r a n t v e r s i o n s of d i s c r e t e c a l l s , v a r i e s w i t h a c t i v i t y . D i s c r e t e c a l l s comprise more than 90% of c a l l i n g d u r i n g f o r a g i n g and t r a v e l l i n g . However, d u r i n g s o c i a l i z i n g and b e a c h - r u b b i n g , b e h a v i o u r s a s s o c i a t e d w i t h c l o s e i n t e r i n d i v i d u a l s p a c i n g and p h y s i c a l i n t e r a c t i o n , the o c c u r r e n c e of v a r i a b l e sounds, a b e r r a n t p u l s e d c a l l s , and w h i s t l e s i n c r e a s e s s i g n i f i c a n t l y . 261 Discrete c a l l s probably serve to keep pod members in touch while dispersed and out of sight of each other. Modifications in c a l l structure appear to r e f l e c t arousal l e v e l . Variable sounds and whistles may convey more subtle information about arousal and soc i a l a f f i l i a t i o n s during close interactions. Repeated encounters with pods demonstrate that each group produces a limited repertoire of discrete c a l l types. In most pods, a l l c a l l types are used in a l l 'active' contexts, although their frequency d i s t r i b u t i o n varies. Few c a l l types could be correlated with any s p e c i f i c behaviour. Recordings of captive whales of known pod o r i g i n indicate that most or a l l of the c a l l s in the repertoire are produced by both sexes, and that repertoires can be stable for periods of at least 15 years. H i s t o r i c a l recordings made in l o c a l waters provide evidence of repertoire persistence over 25 years. K i l l e r whales and other dolphins can mimic and learn new vocal patterns, a ca p a b i l i t y otherwise exclusive to humans among the mammals. It is therefore l i k e l y that c a l l repertoires are passed across generations by c u l t u r a l transmission. A previous study (Bigg 1982) discovered that two types of k i l l e r whales occur in B.C. waters. A population of 'resident' pods i s divided into two communities with exclusive ranges. A th i r d community of 'transient' pods travels throughout the two resident community ranges. Pods within each community associate with one another, but the three communities do not mix. The 16 resident pods in the study area can be divided into four acoustic groups, or 'clans'. Pods within a clan share c a l l 262 types, but no c a l l sharing occurs between clans. Therefore, each clan represents a d i s t i n c t c a l l t r a d i t i o n . C a l l s shared within clans often have consistent s t r u c t u r a l variations unique to pods or sets of pods. These, as well as c a l l s produced exclusively by certain pods, form a system of dia l e c t s within each t r a d i t i o n . Three of the four resident clans belong to the 'northern' resident community, and pods from each associate frequently. Observed patterns of pod association are in many cases unrelated to acoustic relationships. The 'southern' resident community i s comprised of a single clan, and the same appears to be the case for the transient community. The o r i g i n and adaptive s i g n i f i c a n c e of c a l l t r a d i t i o n s and di a l e c t s within the k i l l e r whale population are unknown. It i s probable that a clan represents a single lineage of related pods which has descended from a common ancestor. New pods appear to form by the gradual s p l i t t i n g of formerly large pods along l i n e s of maternal relatedness. This process i s accompanied by d i a l e c t divergence and, possibly, genetic d i f f e r e n t i a t i o n among 'daughter' groups. It i s l i k e l y that each clan has a separate evolutionary history and developed i t s unique c a l l t r a d i t i o n over long periods in geographic i s o l a t i o n . Their occurrence on the B.C. coast may be the result of independent founding events at d i f f e r e n t times in the past. Dialects may represent byproducts of pod evolution and c u l t u r a l d r i f t with no functional s i g n i f i c a n c e , or adaptations with some selective value. Vocal divergence among related pods 263 could result from random copy errors in c a l l learning. However, there i s evidence that repertoire v a r i a t i o n may not occur randomly. Dialects may serve as indicators of kinship or pod identity. As such, d i a l e c t s could function to enhance the usefulness of discrete c a l l s in maintaining pod cohesion and i n t e g r i t y , or to act as a behavioural means for avoiding inbreeding. An active process of acoustic divergence would better explain the apparent innovation of new c a l l types in pod repertoires. The c a l l t r a d i t i o n s and d i a l e c t s of k i l l e r whales described here appear to be unique among not only cetaceans, but a l l mammals. This study has provided an i n i t i a l description of this unusual acoustic system and has speculated on i t s evolution and function. Further research i s required to test these ideas. In-depth analyses of the vocal exchanges within pods must be undertaken to document in d e t a i l the s p e c i f i c behavioural contexts in which c a l l types occur. Additional information on the d i s t r i b u t i o n and s o c i a l associations of pods throughout the year i s required for a more complete comparison with c a l l t r a d i t i o n s and d i a l e c t s . Knowledge of the mating system of k i l l e r whales must be obtained, since t h i s may have important consequences for hypotheses concerning d i a l e c t function. F i n a l l y , annual monitoring of s o c i a l dynamics and vocalizations in a resident community should be continued for as long as is required to document the process of pod formation and dialect d i f f e r e n t i a t i o n . With th i s i t should be possible to construct a model of the evolutionary history of the k i l l e r whale population 2 6 4 in B.C. based on acoustic relationships. Many broad questions remain to be considered. Do similar group-specific d i a l e c t s exist in other cetaceans, or are they a p e c u l i a r i t y of k i l l e r whales, perhaps related to the species' unusually closed s o c i a l system? Are k i l l e r whale d i a l e c t s a byproduct of the delphinid's a b i l i t y of vocal learning, or i s vocal learning a byproduct of the evolution of dialects? 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B e h a v i o r and e c o l o g y of b o t t l e n o s e d o l p h i n s , T u r s i o p s t r u n c a t u s , i n the s o u t h A t l a n t i c . F i s h . B u l l . 77:399-442. Wu r s i g , B., and M. W u r s i g . 1980. B e h a v i o r and e c o l o g y of dusky d o l p h i n s , Lagenorhynchus o b s c u r u s , i n the s o u t h A t l a n t i c . F i s h . B u l l . 77:871-890. W u r s i g , B., and M. W u r s i g . 1983. P a t t e r n s of d a i l y u t i l i z a t i o n of a p r o t e c t e d bay by Hawaiian s p i n n e r d o l p h i n s . A b s t r . F i f t h B i e n n i a l Conf. B i o l . Mar. Mammals, Nov 27 - Dec 1, 1983, B o s t o n , Mass. Z e n k o v i t c h , B.A. 1938. On the grampus or k i l l e r whale, Grampus o r c a L i n . P r i r o d a , 4:109-112. 280 APPENDIX I SUMMARY OF RESIDENT POD ENCOUNTERS 1978 TO 1983 281 Northern Resident Community Encounters: Date Pod(s) 1978 Jul 1 9 A1 , A4, A5 Jul 20 A1 , A4, A5, H Jul 21 A1 Jul 23 A1 , H, 111, 131 Jul 24 A1 , I 1 1 Jul 26 A1 , A4, A5, D J u l 29 A1 , A5, D Jul 30 H, I 1 1 Aug 01 A1 , A4, A5, D Aug 02 AM A1 , A4, A5, C, D Aug 02PM B Aug 05 A1 , A4, A5, B, C Aug 07 A1 , A4, A5, C Aug 1 2 A5, c , 111 Aug 1 7 A1 Aug 18 A1 , (B) Aug 20 A1 1 979 Jul 1 1 A1 Jul 1 2 A1 , A5 Jul 1 3 A1 , H Jul 1 4 A1 Jul 15 A1 , A4, A5, H Jul 22 A1 , A4, A5 Jul 23 A1 , A4, A5 Jul 24 A1 , (A4), A5 Jul 26 A5 Jul 29 A1 , A4, A5 J u l 30 A1 , A4, A5 Aug 01 A1 , A5 Aug 02 A1 Aug 03 A4f B Aug 04 A1 , A4, A5 Aug 05 . A1 , A5 Aug 07 A1 , A5, (B) Aug 1 3 A1 , A4, A5, I 1 Aug 1 4 I 1 Date Pod(s) 1980 Jul 07 Jul 09 Jul 1 0 Jul 1 1 Jul 12 Jul 14 Jul 15 Jul 16 J u l 18 J u l 19 Jul 20 Jul 21 Jul 22 Jul 23 Jul 24 Jul 25 Jul 28 Aug 01 Aug 02 Aug 06 Aug 07 Aug 08 Aug 1 4 Aug 1 5 Sep 09 Oct 01 1 981 Jul 05 J u l 06 Jul 08 J u l 09 Jul 10AM J u l 10AM J u l 1 1 Jul 1 2 J u l 1 3 J u l 14 J u l 1 5 J u l 16 J u l 17 J u l 18 A4, A5, C, D, A5, (C) A4, A5, C, D B B A5, (B) A5, c , D A5, (C) , D A5, D A5, D A4, A5, D A5, D A5, D A4, A5 A5 A4, A5, D A5 B A4, A5, B, D, B, G, I 1 1 B B, G, I 1 1 I 1 I 1 A4, A5 A1 , A5 A5, B A1 B, A5 A5 A5, (B) A1 , A4, A5, B, A1 , A5 A5 A4 A1 , A4, A5 A1 , A4, (A5) A5 A1 , A4 A1 , A4, (A5) 283 Date Pod(s) 1981 - cont'd... Jul 21 A1, A4, A5, G, 111, 131, R, W Jul 23 A l , A4, A5 Jul 24 A1, A4, A5, 111, 131, W Jul 27 A1, A4, A5 Jul 29 A1, A4, A5 Jul 30 A1, A4, A5 Jul 31 A1, A4, A5 Aug 01 A1, A4, A5 Aug 02 A1, A4, A5 Aug 03 A l , A4, A5 Aug 04 A1, A4, A5 Aug 05 A1, A4, A5 Aug 06 A l , A4, A5 .Aug 07 A1, A4, A5 Aug 08 A1, A4, A5 Aug 09 A1, A4, A5 Aug 26 B Aug 27 B Aug 28 B, H, I 1 , I 11, 131 Aug 29 B, (A1, A4, A5) Aug 30 A1, A4, A5, H, 131 1 982 " J u l 09 H J u l 10 A1, H J u l 11 B Jul 11 B, D, H, 11 J u l 12 A4 Jul 14 A1, C, H J u l 16 A5, (A1, C), G, H, 11, 111, 131, W Jul 17 A1 J u l 18 A1, A5, B, D, H, 11 J u l 20 A1, A5, G J u l 21 B Jul 22 A1, A4 J u l 23 A1, A4 J u l 24 A1, A4, A5, B, G Jul 25 A1, A4, (A5, B) Jul 26 A1, A4, A5, B, C, G, 111, 131, W J u l 27 C, 111, W J u l 28 A1, A4 J u l 29 B Aug 02 A1, B, H Aug 03 A1, A4, A5, B Aug 04 B 284 Date Pod(s) 1982 - cont'd... Aug 06 A1 , A4, (A5, 111, 131), C, W Aug 07 A1 , A4, A5, C, G, H, 111, 131 Aug 08 A1 , A5 , B, G Aug 09 A1 , A4, A5 Aug 1 1 A1 , A5 1983 Aug 05 A1 Aug 07 A1 , C Aug 09 A1 , A4, C, 11 Aug 1 1 A1 , C Aug 1 2 A1 , A4, C, G, 111, W Aug 13 A1 , G, 111, W Aug 1 4 131 Aug 1 5 A1 Sep 16 A5 Sep 17 A1 , A5 Sep 18 A1 , A5 Southern Resident Community Encounters: Date Pod(s) 1 978 Sep 27 J, K, L Oct 02 J, K, L 1979 May 03 J May 18 J Jun 07 J J u l 16 J, K, L Aug 22 J Aug 26 J Sep 25 J, K, L Date Pod(s) 1980 Jun 02 J Jun 22 K Jun 26 J Aug 05 J, Aug 30 L 1981 Feb 20 J May 22 J May 29 J Sep 1 5 J, Sep 16 L Oct 13 1982 Feb 03 K, Jun 04 J Aug 27 L 1983 Aug 12 J, K, L 286 APPENDIX II SUMMARY OF HISTORICAL FIELD RECORDINGS EXAMINED IN THIS STUDY 287 Appendix 11: H i s t o r i c a l F i e l d Recordings Examined Date Locat ion Pods Present Source Northern Community: Aug 29 1 964 Johnstone S t r a i t A1 , C, R HDF Aug 31 1 964 Johnstone S t r a i t A1 , C, R HDF Aug 08 1970 Blackf i sh Sound A1 , H PS Aug 19 1 971 Blackfish Sound A1 PS Aug 22 1 971 Blackf ish Sound B PS Aug 05 1973 Johnstone S t r a i t A's EH Aug 09 1 973 Johnstone S t r a i t A's EH Aug 10 1 973 Blackfish Sound A1 , C/D, A4, A5, PS I 1 1 , (131?) Aug 1 1 1973 Johnstone S t r a i t A1 , C/D EH Aug 1 2 1 973 Blackf i sh Sound A1 , C/D PS Aug 18 1973 Johnstone S t r a i t A1 , A5, C/D EH Aug 20 1 973 Johnstone S t r a i t A1 , A5 EH Aug 24 1973 Johnstone S t r a i t A1 , A5, B EH Aug 26 1 973 Blackfish Sound A1 PS Aug 27 1 973 Blackfish Sound D PS Aug 30 1 973 Blackf i sh Sound A1 , A5 PS Aug 31 1 973 Blackf ish Sound A1 , C/D A5, C/D, R PS Sep 07 1 973 Blackf ish Sound PS Jul 27 1974 Johnstone S t r a i t A1 , A5 EH Jul 30 1 974 Johnstone S t r a i t A1 , A5, H EH Aug 1 1 1 974 Johnstone S t r a i t A1 , A4 EH Southern Community: Feb 19 1958 Saanich Inlet J DREP Oct 20 1960 Puget Sound J USN Spring 1961 Saanich Inlet J DREP Mid-1960's unknown J, K, L TP Sources: HDF = H.D. Fisher, U of B.C. PS = Paul Spong, OrcaLab EH = E. Hoyt DREP = Defence Research Establishment P a c i f i c USN = United States Navy TP = T. Poulter C o l l e c t i o n * I d e n t i f i c a t i o n s of pods based on vocalizations. 288 APPENDIX I I I DESCRIPTIVE STATISTICS AND ANOVA COMPARISONS OF CALL VARIABLES C a l l t y p e s a r e d e s c r i b e d a c c o r d i n g t o measurements of s t r u c t u r a l s u b d i v i s i o n s , or " p a r t s " , which a r e i d e n t i f i e d n u m e r i c a l l y i n the f o l l o w i n g t a b l e s . In s i m p l e p a r t s , o n l y s i n g l e d u r a t i o n and s i d e b a n d , or harmonic i n t e r v a l measurements were made. In complex p a r t s , s e v e r a l measurements were made, u s u a l l y of s i d e b a n d i n t e r v a l ' s a t v a r i o u s p o i n t s i n the p a r t . S i m u l t a n e o u s narrowband components, or " t o n e s " , were measured when p r e s e n t . No attempt was made t o d e s c r i b e components a t f r e q u e n c i e s of > 8 kHz. S t a t i s t i c a l comparisons a r e ANOVA's w i t h S c h e f f e ' s m u l t i p l e comparisons t e s t i n g a n u l l h y p o t h e s i s t h a t v a r i a b l e measurements were e q u a l . A b b r e v i a t i o n s used i n the t a b l e s a r e as f o l l o w s : C.V. = c o e f f i c i e n t of v a r i a t i o n Dur = d u r a t i o n SBI = si d e b a n d (or harmonic) i n t e r v a l ms = m i l l i s e c o n d s Hz = H e r t z f = f r e q u e n c y ~ f = change i n f r e q u e n c y SB2 = second s i d e b a n d or harmonic I P I = i n t e r p u l s e i n t e r v a l PRL = p u l s e r a t e l e v e l i n g ( o r , p o i n t a t which p i t c h s t o p s i n c r e a s i n g or d e c r e a s i n g ) p = p r o b a b i l i t y l e v e l from S c h e f f e ' s t e s t MD = c a p t i v e whale "Moby D o l l " Sh = c a p t i v e whale "Shamu" Na = c a p t i v e whale "Namu" 64 = 1964 73 = 1973 NORTHERN COMMUNITY CALLS: Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 1339 13. 6 931 1 772 26 P a r t 1 : Dur (ms) A1 212 14. 1 1 30 274 26 SBI (Hz) A1 161 13. 2 120 203 18 P a r t 2: Dur (ms) A1 117 20. 5 78 160 26 P a r t 3: Dur (ms) A1 1011 17. 6 626 1373 26 SBI, s t a r t (Hz) A1 870 17. 7 515 1 135 26 SBI, peak (Hz) A1 1010 5. 5 921 1119 26 SBI, mid (Hz) A1 784 5. 1 715 858 26 SBI, end (Hz) A1 975 1 1 . 5 813 1263 26 Tone: f , s t a r t (Hz) A1 4407 10. 6 3305 5375 24 290 P a r t : 8 -kHz CALL N 1 i i 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n P Duration (ms) B 997 12.2 81 1 1 346 28 ns 11 1051 10.3 839 1 270 26 Part 1 : Dur (ms) B 1 19 29.0 54 220 28 <0.001 11 180 45.6 92 397 29 SBI (Hz) B 80 22.7 52 1 33 20 <0.001 11 55 33.4 24 83 1 5 Part 2: Dur (ms) B 36 47.4 4 66 27 <0.01 I 1 53 45.2 9 90 28 Part 3: Dur (ms) B 798 16.3 607 1 156 28 ns 11 762 16.3 556 1071 29 SBI, s t a r t (Hz) B 815 24.8 399 1 165 28 ns I 1 859 13.9 579 1067 26 SBI, peak (Hz) B 1029 8.8 860 1 297 28 ns I 1 979 19.0 100 1115 28 SBI, mid (Hz) B 708 7.0 610 808 28 <0.001 I 1 788 7.2 694 887 24 con t i n u e d . . . 291 CALL N 1 i i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n p SBI, end (Hz) B 663 7.0 590 767 28 ns 11 697 19.7 100 829 28 Tone; f , s t a r t (Hz) B 3368 23.4 2575 5633 25 <0.001 11 2520 20.3 1970 3898 25 CALL N 1 i i i P a r t : | 1—•, 1 2 3 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) C D Na P a r t U Dur (ms) C D Na 835 10 .6 643 948 31 846 1 4 .8 569 1016 24 901 1 4 .4 687 1171 17 152 30 .6 64 278 31 173 31 . 1 90 320 26 171 31 . 1 89 292 17 c o n t i n u e d . CALL N 1 i i i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 2: SBI (Hz) C 49 18.6 32 77 28 D 49 11.7 37 59 20 Na 40 11.5 32 53 1 7 Dur (ms) C 40 34.6 8 73 31 D 45 37. 1 2 68 26 Na 36 41.0 1 7 59 1 7 P a r t 3: Dur (ms) C 594 13.0 442 730 31 D 580 15 . 1 366 693 26 Na 648 18.9 419 833 17 SBI, s t a r t (Hz) C 828 16.2 544 1080 29 D 940 16.7 507 1 190 26 Na 707 20.4 500 976 1 7 SBI , peak (Hz) C 1035 11.1 588 1 183 31 D 1117 7.9 961 1 441 26 Na 1097 5.8 1 000 1222 17 SBI , mid (Hz) C 674 7.4 571 775 29 D 666 6.9 574 767 26 Na 621 7.0 560 707 1 7 SBI , end (Hz) C 657 8.9 504 757 29 D 685 6.1 599 746 26 Na 657 5.7 598 736 1 7 Tone : f , s t a r t (Hz) C 3884 15.9 3032 5065 1 3 D 3784 13.9 2866 4735 18 Na 31 74 19.1 2614 5422 1 7 293 CALL N1i i i - Measurement Comparisons Measurement C vs D C vs Na D vs Na D u r a t i o n (ms) ns ns ns P a r t 1 : Dur (ms) ns ns ns SBI (Hz) ns <0.001 <0.001 P a r t 2: Dur (ms) ns ns ns P a r t 3: Dur (ms) ns ns ns SBI, s t a r t (Hz) <0.05 <0.05 <0.001 SBI, peak (Hz) <0.05 ns ns SBI, mid (Hz) ns <0.01 <0.05 SBI, end (Hz) ns ns ns Tone: f , s t a r t (Hz) ns <0.01 <0.05 CALL N1iv 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) H 768 12.6 642 1 026 25 P a r t 1: Dur (ms) H 82 37.0 33 1 60 25 SBI (Hz) H 82 20.3 40 1 13 20 P a r t 2: Dur (ms) H 51 40.0 14 1 1 1 25 P a r t 3: Dur (ms) H 632 11.3 517 805 25 SBI, s t a r t (Hz) H 787 11.2 531 916 25 SB I , peak (Hz) H 958 4.3 875 1028 25 SBI, mid (Hz) H 575 10.6 467 704 25 Tone: f , s t a r t (Hz) H 2825 14.2 2330 3498 1 2 CALL N1v D u r a t i o n (ms) A4 827 18. 3 594 1099 20 P a r t 1 : Dur (ms) A4 1 05 21 . 7 60 1 64 20 SBI (Hz) A4 173 15. 6 130 218 17 P a r t 2: Dur (ms) A4 30 42. 2 2 55 20 P a r t 3: Dur (ms) A4 648 20. 4 434 897 20 SBI, s t a r t (Hz) A4 870 15. 4 656 1213 20 SBI, peak (Hz) A4 1428 5. 7 1 292 1568 20 SBI, mid (Hz) A4 1000 6. 9 953 1 150 20 SBI, end (Hz) A4 1012 7. 2 899 1 135 20 Tone: f , s t a r t (Hz) A4 4192 15. 5 3109 5310 18 CALL N2 Measurement Pod Mean C.V. Min Max n Duration (ms) A1 A4 A5 Part j_: Dur (ms) A1 A4 A5 SBI (Hz) Al A4 A5 Part 2: Dur (ms) A1 A4 A5 SBI, s t a r t (Hz) A1 1 A4 1 A5 1 664 21 . 00 51 1 1066 31 654 19. 39 468 942 25 715 17. 26 504 1030 30 71 86. 99 30 395 31 75 89. 83 23 289 25 55 41 . 04 1 6 1 03 30 479 14. 58 291 61 1 30 493 1 1 . 81 373 580 18 473 12. 28 362 574 23 593 20. 68 460 1001 31 578 18. 96 415 775 25 659 18. 07 438 929 30 046 8. 21 830 1191 31 185 9. 12 1022 1419 25 081 9. 1 1 832 1295 30 c o n t i n u e d . . . CALL N2 - c o n t i n u e d . Measurement Pod Mean C.V. Min Max n SBI, 1st peak (Hz) A1 1455 5. 62 1 320 1608 31 A4 1 569 12. 15 1206 2098 25 A5 1 679 1 1 . 45 1 179 2049 30 SBI, end (Hz) A1 1 604 10. 35 1418 2062 31 A4 1 928 1 1 . 20 1 648 2459 24 A5 1 954 17. 57 1515 2766 30 Time t o 1st A1 179 24. 29 98 265 31 peak (Hz) A4 94 25. 50 56 1 68 25 A5 133 19. 85 83 208 30 P a r t 3: Dur (ms) A1 61 47. 56 27 109 7 A4 60 36. 28 32 127 24 A5 66 26. 97 33 1 04 29 f , SB2, end (Hz) A1 5114 27. 33 3829 791 3 8 A4 6384 12. 98 4906 7935 25 A5 6660 1 1 . 86 5352 7943 29 Tone: f , s t a r t (Hz) A1 6396 8. 21 5229 7544 31 A4 6331 7. 90 5590 7114 25 A5 6435 9. 19 4825 7253 26 f , m i d p o i n t (Hz) A1 7631 10. 66 3326 7982 31 A4 731 1 22. 04 2418 8020 17 A5 7869 1 . 70 7559 8081 17 298 CALL N2 - Measurement Comparisons Measurements A1 vs A4 A1 vs A5 A4 vs A5 D u r a t i o n (ms) ns ns ns P a r t 1: Dur (ms) ns ns ns SBI (Hz) ns ns ns P a r t 2: Dur (ms) ns ns ns SBI, s t a r t (Hz) <0.001 ns <0 .001 SBI, 1st peak (Hz) — — SBI, end (Hz) <0.001 <0.001 P. s Time t o 1st peak (Hz) <0.001 <0.001 <0 .001 P a r t 3: Dur (ms) ns ns ns f, SB2, end (Hz) <0.01 <0.001 ns Tone: f , s t a r t (Hz) ns ns ns f , m i d p o i n t (Hz) ns ns ns CALL N3 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) P a r t J_: Dur (ms) P a r t 2: Dur (ms) A l 474 34.8 239 819 28 A4 531 18.3 405 634 5 A5 439 22.4 268 574 1 1 B 731 35.3 509 1 1 02 4 C 628 27.4 438 903 7 A1 27 80.0 8 77 17 A4 22 100.0 1 1 55 4 A5 18 56.5 7 42 9 B 16 12.5 1 4 18 3 C 15 1 A1 51 58.8 8 1 1 1 28 A4 49 45.2 1 7 78 5 A5 69 44.3 21 121 1 1 B 68 19.8 52 85 4 C 91 30.8 45 127 7 cont i n u e d . . . CALL N3 - con t i n u e d . . Measurement Pod Mean C.V. Min Max n SBI, s t a r t (Hz) SBI, peak (Hz) SBI, end (Hz) P a r t 3: Dur (ms) SBI, end (Hz) Al 301 28. 2 A4 343 13. 9 A5 363 16. 5 B 272 17. 5 C 323 — A1 413 33. 6 A4 471 1 1 . 7A5 447 19. 4 B 370 24. 2 C 568 24. 8 A1 286 24. 2 A4 277 26. 7 A5 281 25. 2 B 284 17. 6 C 335 10. 1 A1 440 34. 1 A4 489 18. 3 A5 393 22. 7 B 690 39. 2 C 599 30. 0 A1 123 23. 1 A4 1 18 21 . 4 A5 131 16. 7 B 143 15. 9 C 180 20. 3 193 518 17 276 383 4 271 473 9 222 317 3 ! 250 658 17 422 549 4 307 592 9 274 457 4 429 752 7 170 463 28 237 409 5 156 413 1 1 236 334 4 288 387 7 239 779 28 405 592 5 240 538 1 1 469 1083 4 393 887 7 71 182 28 77 143 5 97 167 1 1 1 17 165 4 126 223 7 CALL N4 P a r t : 8-kHz 4 -0.5 I 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A l 735 29.3 197 1028 39 A4 772 31.3 21 1 1171 35 A5 781 35.3 226 1 1 77 42 P a r t 1 : Dur (ms) Al 723 30.3 1 97 1028 39 A4 719 34.5 21 1 1 125 36 A5 719 36.5 222 1115 42 S B I , s t a r t (Hz) A1 884 22.3 526 1355 39 A4 877 18.0 572 1257 36 A5 906 17.4 530 1269 42 S B I , peak (Hz) Al 1 429 5.5 1230 1576 39 A4 1464 5.2 1246 1710 36 A5 1380 6.7 1 170 1627 42 S B I , end (Hz) Al 1 178 6. 1 1062 1270 7 A4 1205 8.8 995 1 464 30 A5 1 160 10.2 672 1 322 25 " f , upsweep a t A1 252 84.3 13 673 7 end (Hz) A4 416 38.7 1 50 880 30 A5 214 42.4 39 439 25 c o n t i n u e d . 302 CALL N4 - c o n t i n u e d . Measurement Pod Mean C.V. Min Max n P a r t 2: Dur (ms) A1 35 28.7 18 49 1 3 A4 41 26.0 24 73 33 A5 65 27. 1 6 1 00 40 SBI (Hz) A1 709 30.0 395 1056 13 A4 712 14.4 492 949 33 A5 703 9.5 444 791 40 CALL N4 - Measurement Comparisons Measurement A1 vs A4 A1 vs A5 A4 vs A5 D u r a t i o n (ms) P a r t j _ : Dur (ms) SBI, s t a r t (Hz) SBI, peak (Hz) SBI, end (Hz) ~ f , upsweep a t end (Hz) P a r t 2: Dur (ms) SBI (Hz) ns ns ns ns ns <0.05 ns ns ns ns ns <0.05 ns ns <0.001 ns ns ns ns <0.001 ns <0.001 <0.001 ns Measurement Pod Mean C.V. Min Max n Duration (ms) Part 1: Dur (ms) SBI, start (Hz) A1 989 1 1 . 0 703 1 224 33 A4 956 17. 9 504 1 168 1 3 A5 992 24. 6 405 1 281 24 B 842 26. 6 505 1 272 28 H 749 18. 3 595 1 044 20 I 1 663 16. 6 545 916 1 3 A1 953 1 1 . 7 666 1224 33 A4 901 20. 2 427 1121 13 A5 924 25. 8 330 1 190 24 B 785 28. 2 477 1 199 28 H 601 20. 5 459 915 20 I 1 608 15. 7 474 785 13 A1 1035 13. 7 743 1 339 33 A4 998 20. 6 687 1 345 1 3 A5 960 17. 5 570 1213 24 B 1021 8. 5 734 1 179 28 H 1121 15. 6 683 1396 19 I 1 1058 10. 3 891 1318 1 3 cont inued.. 304 CALL N5i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n SBI, mid (Hz) SBI, end (Hz) * f , SB3, 1st peak P a r t 2: Dur (ms) SBI (Hz) A1 1 1 97 12. 2 1009 1 578 33 A4 1230 13. 6 1055 1566 13 A5 1171 8. 7 1005 1 504 24 B 1211 6. 3 1076 1 375 28 H 1281 4. 2 1 155 1359 19 I 1 1211 5. 1 1 1 30 1 346 1 3 A1 1276 16'. 2 1 034 1842 33 A4 1 372 18. 3 9 1 6 1751 13 A5 1277 12. 3 1 071 1682 24 B 1 264 10. 0 1045 1636 28 H 1291 6. 5 1 1 73 1485 19 I 1 1261 5. 3 1 1 59 1419 1 3 A l 378 67. 2 58 970 26 A4 287 43. 0 223 507 5 A5 D • 324 37. 4 151 562 1 1 D H 366 28. 9 1 50 51 1 1 5 I 1 - — A1 29 22.4 1 7 45 29 A4 35 27.3 24 62 1 3 A5 48 23.0 29 69 24 B 26 37.0 1 4 51 28 H 92 32.6 27 140 20 I 1 33 71 . 1 16 108 1 3 A1 714 18.2 467 1044 29 A4 719 18.2 565 968 1 3 A5 771 14.0 525 1061 24 B 491 28.2 300 779 28 H 724 12.2 487 935 19 I 1 512 31.8 284 840 1 3 Tone: f, s t a r t (Hz) A l 5766 25. 6 2585 7916 32 A4 6637 9. 9 5132 7844 13 A5 6314 17. 0 2678 7795 23 B 2588 26. 1 1402 4224 28 H 2936 16. 0 2095 3732 1 7 I 1 2165 17. 0 1805 3092 12 CALL N5i - MEASUREMENT COMPARISONS P a r t 1 P a r t 2 Tone Comparison D u r a t i o n Dur SBI SBI Dur SBI f , s t a r t s t a r t end A1 vs A4 ns ns ns ns ns ns ns A l vs A5 ns ns ns ns <0.05 ns ns A l vs B ns <0.05 ns " ns ns <0.001 <0.001 Al vs H <0.001 <0.001 ns ns <0.001 ns <0.001 A1 vs I 1 <0.00 1 <0.001 ns ns ns <0.00t •cO.001 A4 vs A5 ns ns ns ns <0.01 ns ns A4 vs B ns ns ns ns ns <0.001 <0.001 A4 VS H ns <0.001 ns ns <0.001 ns <0.001 A4 VS I 1 <0.01 <0.01 ns ns ns <0.01 <0.001 A5 vs B ns ns ns ns <0.001 <0.001 <0.001 A5 vs H <0.01 <0.00t <0.05 ns <0.001 . ns <0.001 A5 vs I 1 <0.001 <0.001 ns ns ns <0.001 <0.001 B vs H ns <0.05 ns ns <0.001 <0.001 ns B vs I 1 ns ns ns ns ns ns ns H vs I 1 ns ns ns ns <0.001 <0.01 ns CALL N 5 i i P a r t : 8 -kHz 2 3 "•7*••• t' g ^ g ^ S g ^ g : X ^ J - z ^ J ^ Z ^ ^ g ^ ^ & j l g 0 o!s 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) B 657 9.6 573 759 9 H 736 11.4 640 960 15 I 1 921 10.0 751 1029 9 P a r t 1 : Dur (ms) B 618 8.4 539 717 9 H 553 19.2 461 787 15 I 1 731 10.3 604 806 9 SBI, s t a r t (Hz) B 1 124 7.6 997 1246 9 H 1026 16.9 746 1218 15 I 1 1113 8.6 957 1285 9 SBI, mid (Hz) B 1257 2.8 1215 1 331 9 H 1279 4.4 1211 1410 15 I 1 1299 4.0 1211 1374 9 SBI, end (Hz) B 1283 8.6 1 047 1 366 9 H 1296 5.3 1 175 1399 15 I 1 1331 6.0 1 193 1445 9 ~ f , SB3, B _ _ 1st p a r t (Hz) H 31 1 36.3 91 592 15 I 1 --cont i n u e d . . . CALL N 5 i i - c o n t i n u e d . • • Measurement Pod Mean C.V. Min Max n P a r t 2: Dur (ms) B . 22 23.8 14 30 9 H 92 16.5 66 119 1 5 I 1 33 30.4 17 48 9 SBI (Hz) B 564 37.4 260 866 9 H 71 1 6.2 649 798 15 I 1 508 23.5 362 723 9 P a r t s 3 and 4: Dur (ms) B 1 1 7 9.9 96 133 9 H 90 24. 1 62 1 56 15 I 1 1 32 26.3 84 193 9 P a r t 3: f, peak (Hz) B 6099 6.1 5354 661 2 9 H 4172 1 I 1 7012 11.5 5877 7989 6 P a r t 4: SBI (Hz) B 752 13.3 631 938 9 H 796 11.1 678 1010 15 I 1 891 17.6 569 1 082 9 Tone: f , s t a r t (Hz) B 281 1 30.0 2163 4976 9 H 3231 19.1 2452 4916 15 I 1 2517 16.3 2146 3352 8 308 CALL N7i Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 570 24.1 418 929 27 A4 702 11.5 577 868 19 A5 692 19. 1 496 949 25 P a r t 1: Dur (ms) A1 198 23.3 136 345 27 A4 166 14.4 1 16 215 19 A5 172 21.6 98 255 25 SBI (Hz) A1 147 13.0 120 180 27 A4 172 17.6 144 226 1 3 A5 164 15.1 128 216 22 P a r t 2: Dur (ms) Al 371 33.2 243 653 27 A4 535 13.2 405 679 19 A5 519 21 .7 339 729 25 Time t o PRL A l 84 20.0 57 1 32 27 (ms) A4 75 24.6 50 1 13 19 A5 96 18.6 65 141 25 SBI (Hz) A1 1271 9.0 1092 1477 27 A4 1349 4.5 1223 1466 19 A5 1379 4.6 1281 1506 25 309 CALL N7i - Measurement Comparisons Measurement Al vs A4 Al vs A5 A4 vs A5 Duration (ms) <0.01 <0.01 ns Part J_: Dur (ms) <0.05 <0.05 ns SBI (Hz) ns ns ns Part 2: Dur (ms) <0.001 <0.001 ns Time to PRL ns <0.05 <0.001 (ms) SBI (Hz) ns <0.001 ns CALL N 7 i i 310 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 722 16. .2 516 863 8 A4 720 17. .6 528 872 9 A5 775 17. .3 568 915 9 H 886 19. . 1 495 1223 38 I 1 831 15. . 1 596 989 10 P a r t 1: Dur (ms) A l 174 20. . 1 125 240 8 A4 173 25. .4 86 223 9 A5 153 17. .6 122 187 9 H 160 27. .6 105 303 38 I 1 152 21 . .9 99 200 10 SBI (Hz) A1 160 10. , 1 128 179 8 A4 168 17. .6 121 203 8 A5 135 6. ,8 120 147 9 H 225 17. .7 166 309 24 I 1 210 17. .5 160 247 6 P a r t - 2 : Dur (ms) A1 461 26. ,4 279 597 8 A4 458 16. ,4 366 546 9 A5 541 18. ,5 347 625 9 H 462 1 1 . ,5 344 603 38 I 1 442 22. ,0 263 613 10 c o n t i n u e d . 311 CALL N 7 i i - co n t i n u e d . . . Measurement Pod Mean C.V. Min Max n Time t o PRL (ms) A1 83 15.3 67 105 8 A4 70 20.4 47 92 9 A5 95 33.3 61 152 9 H 77 47.8 46 256 38 11 59 19.6 40 77 10 SBI (Hz) A1 1330 7.5 1 172 1434 8 A4 1313 5.6 1 188 1405 9 A5 1399 5.7 1257 1483 9 H 1 359 3.3 1 1 94 1458 38 I 1 1394 6.6 1264 1581 10 P a r t 3: Dur (ms) A1 85 40.8 42 146 8 A4 88 47.9 40 165 9 A5 81 47.4 38 152 9 H 333 17.4 171 41 1 30 I 1 263 11.5 221 309 9 SBI, s t a r t (Hz) A1 1346 7.9 1 166 1444 8 A4 1309 5.4 1 196 1 381 9 A5 1407 4.9 1278 1471 9 H 1 341 5.1 1 158 1 588 36 I 1 1412 10.5 1 157 1602 10 f , SB2, end (Hz) A1 3986 29.3 2469 5972 8 A4 3855 14.0 3194 4568 9 A5 3963 14.4 3227 4882 9 H 6253 13.1 3205 6921 32 I 1 7021 6.2 6391 7503 10 312 CALL N 7 i i i P a r t : Measurement Pod Mean C.V. Min Max n P Duration (ms) B 768 11.0 626 922 24 <0.05 I 1 695 10. 1 555 786 10 Part 1 : Dur (ms) B 139 21.0 93 182 24 ns 11 163 27.4 97 231 10 SBI (Hz) B 134 17.4 83 175 19 <0.05 I 1 157 7.3 1 37 168 10 Part 2: Dur (ms) B 417 15.4 325 571 24 <0.001 I 1 330 14.4 257 374 10 Time to PRL (ms) B 59 19.6 45 96 24 <0.001 I 1 29 57.9 9 61 10 SBI (Hz) B 647 5.4 566 705 24 ns I 1 678 7.8 630 792 10 continued... 313 CALL N 7 i i i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P P a r t 3: Dur (ms) B I 1 21 1 226 19.3 20.9 168 1 56 359 289 24 10 ns SBI, s t a r t (Hz) B I 1 1259 1275 5.0 4.5 1 149 1 185 1361 1387 24 10 ns f , SB2, end (Hz) B I 1 7642 7896 2.5 3.1 7303 7694 7953 8401 24 10 <0.01 314 CALL N7iv P a r t : 8 -kHz 4-0 0.5 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) C 658 12.9 508 832 28 D 605 20.0 446 851 28 Na 654 11.3 538 800 1 6 P a r t 1: Dur (ms) C 94 29.4 46 144 21 D 88 42.0 45 1 52 23 Na 81 26.8 45 127 1 6 SBI (Hz) C 146 14.9 96 179 1 5 D 143 13.2 107 168 1 9 Na 1 1 1 17.5 85 145 16 P a r t 2: Dur (ms) C 383 9.6 285 460 30 D 340 15.6 254 467 28 Na 377 12.2 307 484 1 6 Time t o PRL (ms) C 71 37.8 43 197 30 D 55 32. 1 33 110 28 Na 39 18.7 27 49 16 SBI (Hz) C 1354 2.1 1285 1401 30 D 1362 2.6 1298 1423 28 Na 1382 4.8 1244 1484 16 c o n t i n u e d . . . 315 CALL N7 i v - c o n t i n u e d . . . Measurement Pod Mean C.V Min Max n P a r t 3: Dur (ms) C 529 9. 6 405 632 28 D 477 16. 3 368 646 28 Na 533 12. 8 440 684 1 6 SBI, s t a r t (Hz) C 3023 15. 5 967 3711 28 D 3388 9. 9 2449 4272 24 Na 3074 8. 1 2686 3543 9 f, SBI, end (Hz) C 6006 11 . 8 5069 7889 28 D 6503 11. 2 5193- 7854 28 Na 5974 9. 8 4592 6807 1 6 CALL N7iv - Measurement Comparisons Measurement C vs D C vs Na D u r a t i o n (ms) ns ns P a r t 1 : Dur (ms) ns ns SBI (Hz) ns <0.001 P a r t 2: Dur (ms) <0.001 ns Time t o PRL (ms) <0.001 <0.001 SBI (Hz) ns ns P a r t 3: Dur (ms) <0.01 ns SBI, s t a r t (Hz) — --f , SB 1, end (Hz) <0.05 ns 316 CALL N8i P a r t : 8-kHz 4-r o Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 614 17.7 369 802 1 5 A4 603 9.2 491 705 22 A5 665 9.8 583 867 29 H 712 11.8 446 880 32 P a r t 1 : Dur (ms) A1 487 19.1 225 623 26 A4 446 12.3 325 548 22 A5 444 14.2 357 602 29 H 312 19.7 101 402 32 I P I , s t a r t (ms) A1 21 16.3 16 30 24 A4 24 18.5 17 32 19 A5 25 17.4 17 36 27 H 29 17.9 19 47 31 P a r t 2: Dur (ms) A1 171 26.7 102 280 26 A4 157 10.9 121 1 94 22 A5 221 10. 1 171 265 29 H 399 10.0 306 478 32 c o n t i n u e d . . . 317 CALL N8i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n SBI , s t a r t (Hz) A1 255 23.4 180 381 12 A4 355 15.0 241 469 22 A5 312 16.5 229 404 29 H 487 25.4 216 677 32 SBI , peak (Hz) A1 377 11.8 323 440 1 1 A4 439 9.0 364 512 22 A5 435 7.9 365 528 29 H 670 25.1 273 913 32 SBI , end (Hz) A1 214 23.7 1 32 348 15 A4 301 14.1 217 378 22 A5 255 14.8 173 323 29 H 277 27.3 1 14 434 32 CALL N8i - Measurement Comparisons Measurement A1 vs A4 A1 vs A5 A4 vs A5 A's vs H D u r a t i o n (ms) ns P a r t U Dur (ms) ns I P I , s t a r t (ms) ns P a r t 2: Dur (ms) ns SBI, s t a r t (Hz) <0.001 SBI, peak (Hz) <0.001 SBI, end (Hz) <0.001 ns <0.05 <0.01 ns ns <0.001 <0.01 ns <0.01 <0.001 <0.001 <0.001 <0.05 <0.05 <0.001 <0.001 ns <0.001 <0.05 <0.01 ns CALL N 8 i i 318 P a r t : 8-kHz 4 I v 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) C 557 17.7 445 801 28 D 552 17.6 407 733 29 Na 649 17.0 451 919 16 P a r t 1: Dur (ms) C 231 15.9 147 303 28 D 263 33.3 1 53 432 28 Na 233 24.9 174 420 16 I P I , s t a r t (ms) C 29 13.4 22 36 27 D 30 10.4 26 37 29 Na 31 12.1 25 38 16 P a r t 2: Dur (ms) C 325 30.7 1 92 582 28 D 297 22.5 228 595 29 Na 416 22.4 277 575 16 SBI, s t a r t (Hz) C 315 24.3 137 457 28 D 295 17.9 1 46 419 28 Na 241 17.9 1 56 351 16 c o n t i n u e d . 319 CALL N 8 i i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n SBI, m i d p o i n t (Hz) C 253 11.1 204 318 28 D 257 8.6 192 309 29 Na 255 10.9 214 307 16 SBI, end (Hz) C 251 7.6 1 93 301 28 D 274 8.7 205 337 29 Na 258 6.7 230 286 16 CALL N 8 i i - Measurement Compar i sons Measurement C vs D C vs Na D vs Na D u r a t i o n (ms) ns <0.01 <0.05 P a r t 1 : Dur (ms) — I P I , s t a r t (ms) n s ns n s P a r t 2: Dur (ms) ns ns <0.001 SBI, s t a r t (Hz) ns <0.001 <0.05 SBI, mid (Hz) ns ns ns SBI, end (Hz) <0.001 ns ns 320 CALL N 8 i i i P a r t : i . • 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n P D u r a t i o n (ms) B 535 10.1 448 623 12 ns 11 544 8.9 509 626 6 P a r t 1: Dur (ms) B 323 19.1 240 437 1 2 ns 11 291 15.6 237 373 6 I P I , s t a r t (ms) B 28 11.5 24 35 1 1 <0.05 I 1 28 8.8 26 33 6 P a r t 2: Dur (ms) B 211 15.0 155 255 12 ns I 1 252 10. 1 226 291 6 SBI, s t a r t (Hz) B 752 20.8 468 962 12 ns I 1 691 35.3 455 1009 5 SBI, peak (Hz) B 858 9.7 678 974 1 2 <0.01 I 1 979 5.4 910 1070 6 SBI, end (Hz) B 569 6.0 514 617 1 2 — 11 614 15.4 445 71 1 6 321 Measurement Pod Mean C.V. Min Max n p D u r a t i o n (ms) B 558 15.3 436 773 1 5 ns 11 522 7.8 478 606 10 P a r t 1: Dur (ms) B 314 22.7 242 554 1 5 ns I 1 292 6.2 269 324 10 I P I , s t a r t (ms) B 34 16.9 27 47 1 5 ns I 1 26 15.6 21 31 10 P a r t 2: Dur (ms) B 244 17.3 185 346 1 5 ns I 1 229 15.1 173 282 10 SBI, s t a r t (Hz) B 425 20.9 249 568 15 <0.01 I 1 371 15.3 324 489 10 SBI, peak (Hz) B 633 12.3 505 759 1 4 — I 1 656 4.0 604 698 10 SBI, end (Hz) B 255 43.2 180 568 15 ns I 1 281 34.6 1 45 470 10 P a r t 3: Dur (ms) B 1 16 35.5 12 156 15 ns I 1 1 12 30. ; 46 1 48 10 CALLS N9i (A1 pod), N 9 i i (A4 pod) and N 9 i i i (A5 pod) P a r t : 8-kHz Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 1082 9.0 889 1269 27 A4 984 14.6 675 1 277 32 A5 933 10.9 743 1 135 32 P a r t 1: Dur (ms) A1 333 19.4 189 490 27 A4 288 19.9 187 428 32 A5 334 23.3 216 51 1 32 SBI (Hz) A1 1 44 12.4 120 181 27 A4 197 17.0 1 32 260 32 A5 148 16.3 1 04 192 32 P a r t 2: Dur (ms) A1 71 25.4 39 104 27 A4 85 25.3 51 131 32 A5 71 16.7 47 101 32 SBI (Hz) A1 656 17.7 467 931 27 A4 652 9.5 500 785 32 A5 617 9.7 457 728 32 cont i n u e d . CALL N9 - continued... Measurement Pod Mean C.V. Min Max n Part 3: Dur (ms) A1 A4 A5 644 501 434 13.4 20.4 8.8 477 314 366 835 705 525 27 32 32 Dur, downsweep at end (ms) A1 A4 A5 46 38.5 13 77 31 SBI, start (Hz) Al A4 A5 1 386 1 577 1410 9.8. 6.0 6.7 1 130 1 287 1 128 1611 1848 1612 27 32 32 SBI, end (Hz) A1 A4 A5 1695 3058 1 730 13.2 9.7 7. 1 1410 2418 1429 2152 3652 201 4 27 32 32 Part 4: Dur (ms) A1 A4 A5 34 108 94 32.7 19.1 15.0 5 70 58 55 1 44 120 27 32 32 SBI (Hz) Al A4 A5 781 866 14.2 12.5 518 633 1043 1069 26 30 ~ f , SB2, upsweep (Hz) Al A4 A5 905 47.4 497 2294 24 CALL N9 - Measurement Comparisons Measurement A l vs A4 A1 vs A5 A4 vs A5 D u r a t i o n (ms) <0.01 <0.001 ns P a r t J_: Dur (ms) ns ns ns SBI (Hz) <0.001 ns <0.001 P a r t 2: Dur (ms) < 0.01 ns <0.01 SBI (Hz) ns ns ns P a r t 3: Dur (ms) <0.001 <0.001 <0.01 SBI, s t a r t (Hz) <0.001 ns <0.001 SBI, end (Hz) <0.001 ns <0.001 P a r t 4: Dur (ms) <0.001 <0.001 <0.01 SBI (Hz) <0.01 CALL N10 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 857 12.3 638 1 022 18 A4 829 14.5 691 1012 8 A5 853 7.0 706 967 27 P a r t It Dur (ms) A1 215 24.0 131 282 13 A4 175 23.8 1 30 233 10 A5 160 24.4 105 242 19 SBI (Hz) A1 1 17 14.0 84 1 36 18 A4 143 22.5 100 203 10 A5 131 27.2 76 215 23 P a r t 2: Dur (ms) A1 201 60.8 65 449 18 A4 1 46 43.7 84 254 10 A5 133 40.2 51 294 27 SBI (Hz) A l 603 11.5 469 730 17 A4 607 16.2 481 745 1 0 A5 565 11.9 433 729 23 cont i n u e d . 326 CALL N10 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 3: Dur (ms) A1 478 15.5 342 654 18 A4 518 15.6 376 603 10 A5 507 10.4 431 635 27 SBI , s t a r t (Hz) A1 913 14.5 451 1 050 18 A4 1 005 11.1 876 1227 10 A5 926 16.1 541 1226 27 SBI , peak (Hz) Al 1 036 8.6 737 1 139 . 18 A4 1114 4.8 1013 1 164 10 A5 1 1 35 7.8 965 1281 27 SBI , end (Hz) A1 796 13.6 576 1053 18 A4 826 11.1 736 974 1 0 A5 891 14.9 655 1171 27 P a r t 4: Dur (ms) Al 40 30.2 26 62 10 A4 43 36.3 22 63 10 A5 99 57.6 22 209 27 SBI (Hz) A1 593 23.9 273 766 1 1 A4 592 18.5 468 745 10 A5 643 13.6 466 847 27 Tone : f , s t a r t (Hz) A1 3996 17.9 2849 5503 13 A4 3721 9.0 3228 4139 9 A5 4051 17.2 2533 551 2 19 327 CALL N10 - Measurement Comparisons Measurement A1 vs A4 A1 vs A5 A4' vs A5 D u r a t i o n (ms) ns ns ns P a r t 1: Dur (ms) ns <0.0l ns SBI (Hz) ns ns ns P a r t 2: Dur (ms) ns <0.05 ns SBI (Hz) ns ns ns P a r t 3: Dur (ms) ns ns ns SBI, s t a r t (Hz) ns ns ns SBI, peak (Hz) ns <0.01 ns SBI, end (Hz) ns <0.05 ns P a r t 4: Dur (ms) ns <0.01 <0.05 SBI (Hz) ns. ns ns Tone: f , s t a r t (Hz) ns ns ns 328 CALL N I 1 i P a r t : 8-kHz 4- r 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 1 389 22.7 987 1937 1 1 A4 1 501 26.7 948 2035 6 A5 1 428 34.4 832 221 6 8 P a r t 1: Dur (ms) A1 1 12 21 . 1 81 163 1 1 A4 122 26.2 84 181 6 A5 107 16.3 89 142 8 SBI (Hz) A1 1073 14.3 727 1315 1 1 A4 925 2.3 901 963 6 A5 1 100 11.7 917 1336 8 P a r t 2: Dur (ms) A1 1078 22.8 653 1480 1 1 A4 1097 32.4 652 1549 6 A5 1 129 43. 1 51 1 1 984 8 SBI (Hz) A1 1027 8.2 840 1 195 1 1 A4 1 061 1 .9 1036 1088 6 A5 1046 9.4 872 1 177 7 cont i n u e d . 329 CALL N11i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 3: Dur (ms) A1 68 27.5 44 1 12 1 1 A4 92 30.8 58 124 6 A5 69 30.7 45 108 8 SBI (Hz) A1 815 11.0 686 971 1 1 A4 863 12.5 668 951 6 A5 919 15.0 731 1095 8 330 CALL N11i i P a r t : kHz Measurement Pod Mean C.V. Min Max D u r a t i o n (ms) B C Na 1384 1 582 1245 16.5 1312 1849 47.2 790 2091 1 4 4 P a r t 1: Dur (ms) SBI (Hz) B C Na 134 189 125 B 1 129 C 1083 Na 919 43.6 5.8 13.9 8.3 146 1 17 313 134 865 1190 836 1019 1 4 4 1 4 4 P a r t 2: Dur (ms) B C Na 1 187 1312 996 16.9 1089 1600 51.8 567 1722 1 4 4 SBI (Hz) B 1111 C 1141 Na 961 9.9 1007 1270 12.0 846 1121 1 4 4 c o n t i n u e d . 331 CALL N 1 1 i i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n Dur, (ms) p u l s e s B C Na 106 65 60 9.1 26.0 20.7 92 33 39 1 19 89 82 5 16 13 I PI (ms) B C Na 67 86 99 24.6 14.4 37.9 52 65 42 83 105 228 4 20 17 P a r t 3: Dur (ms) B C Na 53 80 124 21.8 68.8 63 67 1 03 252 1 4 4 SBI (Hz) B C Na 968 929 868 7.2 861 1011 1 4 1 332 Measurement Pod Mean C.V. Min Max n A l 961 18.3 565 1369 26 A4 847 13.9 432 1088 29 A5 804 14.7 498 1101 27 B 724 13.7 525 881 27 C 757 18.0 517 1063 22 D 744 19.0 450 1 280 37 H 683 15.5 552 1014 27 I 1 808 11.7 674 1 049 16 Na 735 8.0 615 831 15 Part 1: A1 122 18.5 78 193 25 A4 115 33. 1 77 206 29 A5 167 17.7 129 248 27 B 97 19. 1 49 131 27 C 93 22.6 57 149 22 D 85 20.3 48 123 37 H 120 17.2 78 158 27 I 1 124 20.0 61 161 16 Na 65 7.9 61 79 15 continued. 333 CALL N12 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n SBI (Hz) A1 591 10.7 478 719 25 A4 573 16.7 236 709 28 A5 634 8.4 506 734 27 B 470 14.4 350 589 27 C 291 37.5 107 537 22 D 287 29.4 157 467 25 H 439 17.3 237 678 27 I 1 480 15.6 276 591 1 5 Na 338 31.6 221 545 1 3 P a r t 2: Dur (ms) A l 790 20.2 451 1 130 26 A4 671 25.0 230 953 29 A5 483 20.9 233 684 27 B 545 16.0 362 683 27 C 428 31.1 179 615 22 D 375 43.4 69 815 37 H 365 26.6 267 662 27 I 1 537 13.8 441 713 1 6 Na 536 12.1 449 654 1 5 SBI (Hz) A1 236 14.2 176 310 26 A4 298 11.4 217 339 27 A5 308 13.6 229 404 27 B 230 8.4 1 94 276 27 C 261 10.7 215 326 22 D 273 9.2 204 313 37 H 225 13.5 167 275 27 I 1 219 10.5 1 79 255 16 Na 244 11.3 195 285 15 P a r t 3: Dur (ms) A1 55 52.0 33 160 25 A4 43 35.3 22 85 27 A5 1 54 21.7 1 1 5 264 27 B 81 29. 1 44 140 27 C 235 50. 1 90 491 22 D 283 26.3 172 466 37 H 197 14.8 149 256 27 I 1 146 21.4 106 196 16 Na 133 40.5 94 260 15 c o n t i n u e d . CALL N12 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n SBI , s t a r t (Hz) A1 207 22.9 144 340 25 A4 271 11.4 206 325 27 A5 284 14.6 216 392 27 B 389 34.3 168 731 27 C 328 39.7 164 509 22 D 242 17.1 180 343 37 H 208 16.7 1 54 286 27 I 1 184 16.9 148 259 16 Na 874 12.1 665 1009 1 5 SBI , end (Hz) A1 194 46.3 96 402 25 A4 245 36. 1 85 470 28 A5 698 15.0 498 1011 27 B 1 320 72.7 696 3618 27 C 1 333 11.6 1 008 1676 22 D 1 329 4.1 1 176 1414 37 H 1088 10.1 943 1 364 27 I 1 1035 26.2 607 1 364 16 Na 1362 10.1 1113 1669 15 CALL N12 - MEASUREMENT COMPARISONS Comparison D u r a t i o n P a r t 1 P a r t 2 P a r t 3 Dur SBI Dur SBI SBI s t a r t SBI end Al vs A4 ns ns ns ns <0.001 ns ns A1 vs A5 <0.01 <0.01 ns <0.001 <0.001 ns <0.01 A1 vs B <0.001 ns <0.001 <0.001 ns <0.001 <0.001 Al vs C <0.001 ns <0.001 <0.001 ns <0.001 <0.001 Al vs D <0.001 <0.05 <0.001 <0.001 <0.0 1 ns <0.001 Al vs H <0.001 ns <0 .00 1 <0.001 ns ns <0.001 A1 vs I 1 ns ns <0.05 <0.00l ns ns <0.001 A4 vs A5 ns <0.001 ns <0.001 ns ns <0.05 A4 vs B ns ns <0.0t ns <0.001 <0.001 <0.001 A4 vs C ns ns <0.001 <0.001 <0.05 ns <0.001 A4 vs D ns ns <0.00 1 <0.001 ns ns <0.001 A4 vs H <0.01 ns <0.001 <0.001 <0.001 ns <0.001 A4 vs I 1 ns ns ns ns <0.001 <0.05 <0.001 A5 vs B ns <0.001 <0.001 ns <0.001 <0.001 <0.001 A5 vs C ns <0.001 <0.001 <0.001 <0.001 ns <0.001 A5 vs D ns <0-001 <0.001 ns <0.01 ns <0.001 A5 vs H ns <0.0 1 <0.001 ns <0.001 <0.05 <0.05 A5 vs I 1 ns <0.05 <0.001 ns <0.001 <0.0 1 ns B vs C ns ns <0.001 ns ns ns ns B VS D ns ns <0.001 <0.00l <0.001 <0.001 ns B vs H ns ns ns <0.0 1 ns <0.001 ns B vs I 1 ns ns ns ns ns <0.001 ns C vs D ns ns ns ns ns <0.01 ns C VS H ns ns <0.001 ns <0.05 <0.001 ns C VS I 1 ns ns <0.001 ns <0.05 <0.001 ns D vs H ns <0.05 <0.001 ns <0.001 ns ns D vs I 1 ns <0.05 <0.001 <0.05 <0.001 ns ns H VS I 1 ns ns ns <0.05 ns ns ns L O L O L n CALL N13 336 0.5 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A4 523 17.0 426 600 3 A5 666 7.5 562 745 20 P a r t 1: Dur (ms) A4 133 1 . 1 1 32 1 34 2 A5 147 34.9 55 261 1 7 SBI (Hz) A4 186 31.9 144 228 2 A5 142 16.6 96 183 16 P a r t 2: Dur (ms) A4 80 52.6 41 125 3 A5 87 32.9 48 1 46 20 SBI (Hz) A4 673 9.2 629 717 2 A5 519 22. 1 312 756 18 c o n t i n u e d . CALL N13 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 3: Dur (ms) A4 276 17.8 236 331 3 A5 384 16.0 296 551 20 SBI , s t a r t (Hz) A4 1073 35.0 665 1 405 3 A5 763 32. 1 401 1289 20 SBI , 1st peak (Hz) A4 1716 47.6 1098 2643 3 A5 1 194 9.8 1091 1637 20 SBI , d i p (Hz) A4 775 55.0 486 1 265 3 A5 742 13.2 586 927 20 SBI , 2nd peak (Hz) A4 1001 46.9 694 1 542 3 A5 1 165 6.5 1047 1 304 20 SBI , end (Hz) A4 1321 87.9 536 2655 3 A5 926 18.7 430 1 1 75 20 P a r t 4: Dur (ms) A4 49 32.8 40 68 3 A5 45 28.8 23 70 1 9 SBI (Hz) A4 847 72.2 346 1 529 3 A5 675 16.5 456 893 19 Tone : f , s t a r t (Hz) A4 3463 7.1 3289 3637 2 A5 4783 14.8 3343 6234 1 7 CALL N l 6 i 0 1 0.5 1 .0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) B 1301 13.3 791 1495 28 Part 1 : Dur (ms) B 745 20.8 397 940 28 SBI, s t a r t (Hz) B 1047 7.4 891 1 166 28 SBI, end (Hz) B 201 1 13.7 1 352 2386 28 ~ f , SB2 (Hz) B 2297 23.0 1385 3155 28 Part 2: Dur (ms) B 43 34.2 22 81 28 SBI (Hz) B 746 21 .5 505 916 10 c o n t i n u e d . . . CALL N16i - c o n t i n u e d . Measurement Pod Mean C.V. Min Max n P a r t 3: Dur (ms) B 445 14.0 262 564 28 SBI, s t a r t (Hz) B 2859 10.7 2174 3822 27 f, peak (Hz) B 6176 8.9 4436 7300 27 f , end (Hz) B 4001 11.5 3182 4788 28 P a r t 4: Dur (ms) B 27 20. 1 17 42 26 SBI (Hz) B 789 11.3 601 908 26 Tone: f , s t a r t (Hz) B 2243 12.1 1881 2966 23 340 CALL N16H Measurement Pod Mean C.V. Min Max n Duration (ms) C 1285 24.6 842 2250 50 D 1228 27.0 564 1 778 25 Na 1114 17.3 785 1695 26 Part 1 : Dur (ms) C 708 34. 1 326 1 506 50 D 661 29.3 298 977 25 Na 557 28.3 305 983 26 SBI, s t a r t (Hz) C 1021 10.7 789 1233 50 D 1 100 14.9 691 1470 25 Na 1008 14.8 759 1410 26 SBI, end (Hz) C 1977 36.5 1233 4136 50 D 1832 27.4 1327 3049 25 Na 1 406 14.4 1 186 1895 26 ~ f , SB2 (Hz) C 1 770 73.9 398 5809 50 D 1352 57.3 209 2855 25 Na 880 52.6 277 2022 26 Dur, gap between c 79 34.3 39 136 20 P t s . 1 and 2 (ms) D 88 30.8 45 135 13 Na 71 32. 1 28 1 07 8 cont inued. 341 CALL N l 6 i i - co n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 2: Dur (ms) C 63 22.8 39 101 50 D 68 23.9 42 120 25 Na 75 19.5 37 96 26 SBI (Hz) C 809 11.3 649 966 50 D 828 10.5 670 1 029 24 Na 743 14.0 597 949 25 P a r t 3: Dur (ms) C 409 19.5 219 569 50 D 382 26.4 152 567 25 Na 347 16.1 258 496 26 SBI, s t a r t (Hz) C 2757 10.0 2033 3328 50 D 2889 11.7 2283 3535 25 Na 2999 8.9 2422 3621 25 f, peak (Hz) C 6735 9.7 5275 8490 50 D 7282 9.9 5794 8821 25 Na 6438 5.3 5590 71 25 26 f , SB2, end (Hz) C 2899 11.3 1919 3653 50 D 3048 12.6 2427 3962 25 Na 2799 8.5 2405 3368 26 P a r t 4: Dur (ms) C 61 18.9 40 90 50 D 65 27.6 41 1 1 3 25 Na 96 18.8 46 136 26 SBI (Hz) C 871 7.2 727 1038 50 D 904 13.2 701 1191 25 Na 767 13.1 592 993 25 Tone: f , s t a r t (Hz) C 2723 20. 1 1716 4270 36 D 3581 17.6 2250 5066 22 Na 3003 17.6 2035 3951 26 CALL N 1 6 i i - Measurement Comparisons Measurement C vs D C vs Na D vs Na D u r a t i o n (ms) ' ns ns ns P a r t 1: Dur (ms) ns <0.05 ns SBI, s t a r t (Hz) ns ns ns SBI, end (Hz) ns <0.001 <0.05 ~ f , SB2 (Hz) ns <0.0 1 ns Dur, gap (ms) ns — — P a r t 2: Dur (ms) ns <0.01 ns SBI (Hz) ns <0.05 <0.01 P a r t 3: Dur (ms) ns <0. 01 ns SBI, s t a r t (Hz) ns <0.01 ns f , peak (Hz) <0.01 ns <0.001 f, SB2, end (Hz) ns ns <0.05 343 CALL N 1 6 i i i 0 0.5 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) H I 1 1392 1302 10.8 7.5 963 1 233 1624 1 372 1 5 2 P a r t 1 : Dur (ms) H I 1 805 714 19.5 3.1 398 699 1019 730 1 5 2 SBI, s t a r t (Hz) H I 1 1 108 925 20.7 13.5 458 837 1392 1014 15 2 SBI, end (Hz) H I 1 2068 1950 7.2 2.7 1746 1913 231 1 1988 15 2 ~ f , SB2 (Hz) H I 1 2210 2199 18.1 1.7 1 569 2172 3287 2226 1 5 2 cont i n u e d . 344 CALL N1 6 i i i - continued. • • * Measurement Pod Mean C.V. Min Max n Part 2: Dur (ms) H 1 1 1 11.0 93 1 37 15 11 76 39. 1 55 97 2 SBI (Hz) H 949 3.7 864 990 1 5 11 932 3.8 907 957 2 Part 3: Dur (ms) H 430 10.0 384 521 1 5 I 1 459 9.7 428 491 2 SBI, start (Hz) H 3008 6.3 2824 3419 15 I 1 2904 7.3 2754 3054 2 f, peak (Hz) H 3943 8.6 3285 4768 1 5 I 1 4036 3.6 3933 41 39 2 Part 4: Dur (ms) H 22 16.8 1 6 30 1 5 I 1 24 11.8 22 26 2 SBI (Hz) H 664 10.3 477 748 1 5 I 1 651 6.3 622 680 2 Tone: f, start (Hz) H 3021 12.2 2391 3484 6 I 1 2001 1 345 CALL N!6iv Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) 11 1273 10.3 1024 1 534 26 Part 1 : Dur (ms) 11 749 15.0 599 1 003 26 SBI, s t a r t (Hz) 11 1009 7.0 841 1 120 26 SBI, end (Hz) 11 1600 10.2 1329 1935 26 ~ f , SB2 (Hz) 11 1213 28.0 705 21 22 26 Part 2: Dur (ms) 11 493 13.8 384 631 26 SBI, s t a r t (Hz) 11 1600 10.2 1329 1935 26 f, peak (Hz) 11 4493 6.9 3823 4994 25 f, end (Hz) 11 3136 13.8 2831 3441 2 Part 3: Dur (ms) 11 30 30.2 20 54 26 SBI (Hz) 11 795 18.7 548 1095 26 Tone: f, s t a r t (Hz) 11 2210 14.0 1587 2990 21 346 CALL N17 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A5 843 8.4 700 966 19 Part 1 : Dur (ms) A5 116 64.7 1 5 219 18 SBI (Hz) A5 163 14.5 108 201 1 1 Part 2: Dur (ms) A5 441 15.0 297 583 19 SBI, s t a r t (Hz) A5 619 12.5 513 750 19 SBI, peak (Hz) A5 1516 8.0 1293 1805 19 SBI, end (Hz) A5 841 16.3 575 1066 19 Part 3: Dur (ms) A5 226 21 .5 141 328 19 SBI, peak (Hz) A5 2037 25.9 1354 2985 19 SBI, end (Hz) A5 1987 19.5 1556 2678 6 continued... 347 CALL N1 7 - c o n t i n u e d . . • Measurement Pod Mean C.V. Min Max n Part i : Dur (ms) A5 60 41.7 31 81 19 SBI , end (Hz) A5 988 18.2 668 1310 19 Tone : f, s t a r t (Hz) A5 3869 5.9 3401 4121 10 CALL N18 P a r t : , r - r — r Measurement Pod Mean C.V. Min Max n Duration (ms) B 678 29.2 363 1 145 22 C 765 45.2 382 1 053 3 Part 1: Dur (ms) B 400 42.2 184 826 25 C 463 61.0 152 704 3 SBI, s t a r t (Hz) B 495 20.2 272 713 25 C 522 42.2 384 776 3 cont i n u e d . . . 348 CALL N18 - con t i n u e d . . . Measurement Pod Mean C.V. Min Max n SB I , end (Hz) B 568 19.3 372 737 25 C 570 24.0 436 710 3 P a r t 2: Dur (ms) B 38 23.8 23 54 25 C 45 18.5 40 55 3 SBI (Hz) B 356 16.6 290 503 18 C 475 7.0 452 499 2 P a r t 3: Dur (ms) B 1 77 18.5 122 249 25 C 213 26.0 1 52 260 3 f, s t a r t (Hz) B 2489 15.0 1 298 2946 25 C 2550 24.4 21 42 3268 3 f, peak (Hz) B 5597 9.1 4682 6619 25 C 5840 10.0 5261 6427 3 f, end (Hz) B 2801 20.2 1 728 3910 25 C 3042 9.4 2716 3250 3 P a r t 4: Dur (ms) B 41 33. 1 19 68 22 C 42 14.4 37 49 3 SBI (Hz) B 361 19.5 263 555 22 C 642 16.5 538 750 3 Tone: f , s t a r t (Hz) B 2288 25.7 1 383 4497 20 C — 349 CALL N19 P a r t : 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A4 545 1 4 .0 409 661 23 SBI, s t a r t (Hz) A4 1 1 52 1 7 .5 738 1 597 23 SBI, 1st peak (Hz) A4 1566 3 .4 1411 1652 23 SBI, d i p (Hz) A4 1335 4 .6 1 1 37 1 434 23 SBI, 2nd peak (Hz) A4 1753 1 1 .5 1 540 2571 23 SBI, end (Hz) A4 1470 13 .0 1 1 06 1814 23 350 CALL N20 Part: 8-kHz 4 -1.0 s Measurement Pod Mean C.V. Min Max n Duration (ms) B 679 19.4 371 892 30 c 51 1 22.5 324 715 16 D 535 20.6 368 757 29 I 1 649 12.4 592 706 2 Time to peak (ms) B 451 26.2 238 709 30 C 328 25.4 203 478 1 6 D 320 27.2 206 515 29 I 1 436 9.1 408 464 2 SBI, start (Hz) B 210 18.5 1 33 314 30 C 246 27.9 164 440 16 D 268 45.4 128 679 29 I 1 262 1 2. 1 240 285 2 SBI, peak (Hz) B 464 20.3 216 693 30 C 781 35.0 404 1 242 16 D 928 25. 1 409 1 287 29 I 1 484 22.5 407 561 2 SBI, end (Hz) B 217 40.4 73 367 30 C 383 49.6 160 791 16 D 402 36.2 172 860 29 I 1 296 18.8 257 336 2 351 CALL N20 • - Measurement Compar i sons Measurement B vs C B vs D C vs D Duration (ms) <0.001 <0.001 ns Time to PRL (ms) <0.01 <0.001 ns SBI, start (Hz) ns ns ns SBI, peak (Hz) <0.001 <0.001 ns SBI, end (Hz) <0.01 <0.001 ns 352 CALL N21 P a r t : 8-kHz 4 -r 0.5 1.0 s Measurement Pod Mean C.V. Min Max D u r a t i o n (ms) P a r t J_: Dur (ms) P a r t 2: Dur (ms) SBI, peak (Hz) P a r t 3: Dur (ms) Tone: f , s t a r t (Hz) B 381 10.8 302 444 20 B 125 23.2 49 181 20 B 54 14.5 42 74 20 B 795 23.0 367 1015 20 B 201 13.8 145 256 20 B 3442 11.6 2330 3922 20 353 CALL N23i P a r t : 8-kHz 4 - l 0.5 1.0 s Measurement Pod Mean C.V. Min Max n P D u r a t i o n (ms) 11 1 908 8.2 782 1 045 29 <0.001 131 819 7.2 743 957 26 P a r t 1: Dur (ms) 11 1 397 18.3 298 557 29 ns 131 372 17.7 266 478 26 SBI, s t a r t (Hz) 11 1 1476 9.5 1 185 1665 28 ns 131 1476 7.7 1191 1648 25 SBI, mid (Hz) 11 1 1771 7.9 1452 1949 29 ns 131 1785 8.6 1510 1994 26 P a r t 2: Dur (ms) 11 1 510 14.3 375 640 29 <0.001 131 447 11.6 358 545 26 Dur, downsweep 11 1 128 30.7 64 196 29 <0.001 at end (ms) 131 97 25.4 49 147 26 SBI, s t a r t (Hz) 11 1 847 9.2 748 1056 29 ns 131 844 11.4 695 1096 26 SBI, peak (Kz) 11 1 1247 9.9 1042 1482 29 ns 131 1258 12.8 1066 1592 26 cont i n u e d . 354 CALL N2 3 i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P SBI, end (Hz) 111 390 26.5 242 656 29 <0.0l 131 477 20.5 323 788 26 Tone: f , s t a r t 111 5328' 4.0 4845 5682 29 ns (Hz) 131 5334 3.8 5044 5633 26 3 5 5 CALL N 2 3 i i P a r t : 8 — kHz 4 -, 1 1 0 0.5 f 1 .0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (Hz) G 802 15.9 438 1053 33 P a r t 1: Dur (ms) G 349 23.0 237 528 33 SBI, s t a r t (Hz) G 1452 6.9 1171 1 609 33 SBI, mid (Hz) G 1 562 5.2 1 447 1 828 33 P a r t 2: Dur (ms) G 452 20.6 1 54 639 33 Dur, downsweep a t end (ms) G 59 33.5 10 104 33 SBI, s t a r t (Hz) G 1058 7.1 833 1208 33 SBI, peak (Hz) G 1050 6.6 879 1 190 33 SBI, end (Hz) G 726 26. 1 306 1121 33 Tone: f , s t a r t (Hz) G 5147 2.8 4939 5526 33 356 CALL N24 1 0 1 0.5 1 !o s Measurement Pod Mean C.V. Min Max n P D u r a t i o n (ms) 11 1 950 18.1 621 1 399 21 ns 131 938 19.7 641 1313 10 P a r t 1: Dur (ms) 11 1 339 37.5 1 1 5 707 21 ns 131 365 21 .9 223 483 10 SBI (Hz) 11 1 828 7.3 709 1 004 21 ns 131 791 5.0 71 1 863 10 P a r t 2: Dur (ms) I 1 1 441 26.0 155 584 21 ns 131 470 17.5 365 663 10 SBI, s t a r t (Hz) I 1 1 1238 18.1 947 1762 20 <0.01 131 1514 14.1 1243 1916 10 SBI, peak (Hz) 11 1 1579 9.4 1356 1906 21 <0.05 131 1465 8.2 1354 1762 10 c o n t i n u e d , 357 CALL N24 - cont i n u e d . . . Measurement Pod Mean C.V. Min Max n P P a r t 3: Dur (ms) I 1 1 131 156 98 37.6 36.3 75 50 300 309 21 10 <0.05 SBI, s t a r t (Hz) I 1 1 131 792 506 30.6 43.6 454 202 1 1 76 1047 21 10 ns SBI, end (Hz) 111 131 378 228 46.9 44.9 191 1 32 786 495 21 10 <0.01 Tone: f , s t a r t (Hz) I 1 1 131 6691 6187 7.5 2.0 6223 5977 7990 6362 20 9 <0.01 358 CALL N25 P a r t : 8 kHz ~ ----1 0 0.5 "1 ' 1 .0 s Measurement Pod Mean C.V. Min Max n P D u r a t i o n (ms) G 11 1 932 1 1 23 11.8 17.8 782 682 1230 1667 28 32 <0.001 P a r t 1: Dur (ms) G I 1 1 122 95 12.5 18.4 98 61 160 147 28 32 <0.001 SBI (Hz) G I 1 1 725 555 11.3 22.7 561 239 866 833 28 32 <0.001 P a r t 2: Dur (ms) G I 1 1 518 324 19.6 41.6 381 94 749 513 28 32 <0.001 SBI, s t a r t (Hz) G 11 1 201 7 2340 10.5 13.5 1719 1708 2519 3001 28 32 <0.001 SBI, end (Hz) G 11 1 1774 1815 8.6 14.6 1485 1278 2172 2332 28 32 ns cont i n u e d . . . 359 CALL N25 -• continued.. • Measurement Pod Mean C.V. Min Max n P Part 3: Dur (ms) G I 1 1 1 1 1 66 19.6 41.1 78 15 158 124 28 32 <0.00 SBI (Hz) G I 1 1 682 721 21 . 1 46. 1 431 373 1012 1 321 28 32 ns Part 4: Dur (ms) G I 1 1 185 637 26.5 48.4 1 15 222 335 1205 26 32 <0.00 SBI, start (Hz) G I 1 1 701 795 23.6 42.5 470 384 1083 1295 28 32 ns SBI, peak (Hz) G I 1 1 1 1 20 1066 20.7 44.3 639 486 1 486 1 755 28 32 ns SBI, end (Hz) G I 1 1 377 352 32.6 15.8 251 252 875 466 26 32 ns Tone: f, start (Hz) G 111 7600 7416 3. 1 4.7 7342 6890 7918 7994 6 20 ns 360 CALL N26 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) 11 1 788 10.9 627 884 10 P a r t 1: Dur (ms) 111 1 94 23.5 93 264 10 SBI (Hz) 111 1 07 9.4 96 1 20 10 P a r t 2: Dur (ms) 111 148 16.1 103 176 10 SBI (Hz) 111 447 18.9 348 595 10 P a r t 3: Dur (ms) 111 97 24.9 66 129 10 SBI (Hz) 111 1767 11.0 1450 2019 9 P a r t 4: Dur (ms) 111 349 18.6 202 420 10 I P I , s t a r t (ms) 111 25 17.4 19 33 10 I P I , end (ms) 111 83 10.9 66 97 10 361 CALL N27 P a r t : , • 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 498 17.8 365 663 1 3 Part 1: Dur (ms) A1 191 13.4 1 40 242 13 SBI (Hz) Al 183 24. 1 96 238 1 2 Part 2: Dur (ms) A1 306 29.8 161 421 13 SBI, s t a r t (Hz) A1 865 8.8 681 950 13 SBI, mid (Hz) Al 928 7.6 832 1055 13 SBI, end (Hz) A1 61 1 16.8 413 750 13 Tone: f , s t a r t (Hz) A1 3217 16.0 251 1 4366 12 362 CALL N28 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) G 587 15.6 442 737 22 P a r t 1: Dur (ms) G 315 25.3 184 460 22 SBI, s t a r t (Hz) G 1 380 12.3 1 1 49 1795 22 SBI, mid (Hz) G 1659 7.9 1 341 1875 22 P a r t 2: Dur (ms) G 405 14.3 324 516 22 SBI, s t a r t (Hz) G 1704 6.4 1 477 1894 22 SBI, d i p (Hz) G 746 6.2 662 843 22 SBI, end (Hz) G 2001 14.9 1 490 2621 22 Tone: f , s t a r t (Hz) G 5237 4.5 4894 5742 22 363 CALL N29 Measurement Pod Mean C.V. Min Max n Durat i o n (ms) G 637 13.2 485 773 31 P a r t Is Dur (ms) G 362 24.0 21 1 533 31 SBI, s t a r t (Hz) G 1423 15.1 849 1811 31 SBI, mid (Hz) G 1711 8.6 1 449 1 972 31 P a r t 2: Dur (ms) G 201 11.2 139 235 31 SBI, s t a r t (Hz) G 1681 15.4 809 2032 31 SBI, d i p (Hz) G 728 11.3 552 895 28 SBI, end (Hz) G 1 696 25.4 723 2821 30 P a r t 3: Dur (ms) G 76 22.8 53 1 33 30 SBI, end (Hz) G 691 32.3 334 1379 31 Tone: f , s t a r t (Hz) G 5316 3.8 4915 5741 25 364 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) I 1 1 131 1074 1 130 P a r t 1: Dur (ms) I 1 1 131 289 425 P a r t 2: Dur (ms) 11 1 131 785 705 Dur, l o p a r t s (ms) I 1 1 131 78 66 Dur, h i p a r t s (ms) I 1 1 131 81 92 f, l o p a r t s (Hz) I 1 1 131 728 1566 f, h i p a r t s (Hz) I 1 1 131 201 5 2718 18.8 841 1566 12 ns 20.5 699 1574 10 33.3 184 532 1 2 <0.05 43.3 103 648 10 19.7 505 1034 1 2 ns 14.4 585 931 10 19.4 38 106 36 <0.05 24.2 32 107 30 21.5 43 115 36 ns 14.0 29 73 29 13.7 513 945 36 <0.001 11.0 1 198 1983 30 11.5 1417 2554 36 <0.05 29. 1 1901 4578 29 3 6 5 Measurement Pod Mean C.V. Min Max n P Duration (ms) R 1206 13.6 853 1 449 15 <0.05* W 1 045 17.8 620 1 330 19 64 936 12.4 801 1 1 46 8 73 1018 6.2 933 1 082 5 Part 1 : Dur (ms) R 1094 15.4 695 1 321 1 5 <0.01 W 921 18.3 553 1 187 1 9 64 897 10.2 781 1066 8 73 970 3.8 933 1030 5 SBI, s t a r t (Hz) R 391 16.5 266 502 1 5 ns W 352 13.1 263 428 19 64 400 16.6 310 483 8 73 289 16.4 235 339 5 SBI, mid (Hz) R 1 1 32 31.4 583 1756 15 ns W 1 190 25.0 753 1917 19 64 920 15.3 707 1 108 8 73 1110 40.5 654 1669 5 SBI, end (Hz) R 2925 8.2 2482 341 4 15 ns W 2960 11.0 2339 3640 19 64 2661 14.9 1912 2987 8 73 2761 13.7 2350 3192 5 continued. 366 CALL N32i -- c o n t i n u e d . . • Measurement Pod Mean C.V. Min Max n P P a r t 2: Dur (ms) R 11 1 35. 1 42 1 58 15 ns W 1 23 36.7 51 229 19 64 96 28.3 80 1 28 3 73 1 20 5.9 1 1 5 1 25 2 f, SB1, peak (Hz) R 581 1 11.5 4635 6699 15 <0.01 W 5169 9.0 4439 6035 19 64 4521 7.5 4064 4785 4 73 5383 10.2 4995 5771 2 f , SB1, end (Hz) R 3072 13.8 2456 3808 10 ns W 291 3 10.4 2441 3571 18 64 2930 1 .3 2904 2957 2 73 2259 1 Tone: f , s t a r t (Hz) R 1769 36.8 607 3010 12 ns W 2285 31.4 879 3341 18 64 3005 32.4 1 700 4644 8 73 1 072 48.3 686 1959 5 f , end (Hz) R 6939 9.3 5682 7549 10 ns W 6397 11.6 5427 7979 19 64 6347 3.4 6097 6778 8 73 5066 6.6 471 5 5500 4 ANOVA comparisons between R and W pods o n l y . 367 CALL N32ii Measurement Pod Mean C.V. Min Max n Du r a t i o n (ms) R 73 1 353 1 103 20.4 11.7 958 989 1 856 1 243 18 3 Part 1 : Dur (ms) R 73 902 512 25.4 23.9 539 387 1266 632 18 3 SBI, s t a r t (Hz) R 73 470 388 14.0 6.6 389 368 620 417 18 3 SBI, mid (Hz) R 73 557 891 13.0 8.8 352 801 679 938 18 3 Part 2: Dur (ms) R 73 376 496 15.6 6.6 303 464 500 530 18 3 SBI, end (Hz) R 73 3201 3314 4.1 5.8 2870 2850 3396 3661 18 3 cont inued. 368 CALL N 3 2 i i - cont i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 3: Dur (ms) R 73 78 95 32.0 23.2 36 73 139 1 1 6 1 7 3 f, SBI, end (Hz) R 73 5862 5583 8.7 2.5 4897 5479 6661 5739 18 3 Tone: f, s t a r t (Hz) R 73 1936 857 41.5 1 .6 818 848 3394 867 1 1 2 f, l e v e l (Hz) R 73 5993 5718 7.6 3.6 5382 5571 6914 5865 17 2 f, end (Hz) R W 6382 6219 4.0 5872 6768 1 5 369 CALL N33 P a r t : 8 -kHz /•/IT Measurement Pod -Mean C.V. Min Max n D u r a t i o n (ms) R 949 10.5 750 1 1 54 22 W 889 10.1 717 1039 1 4 64 923 13.0 742 1 108 20 73 1063 13.5 755 1 273 1 1 P a r t 1: Dur (ms) R 178 27.4 90 282 22 W 190 39.2 85 370 1 4 64 179 22.8 1 28 286 20 73 226 27. 1 103 317 1 1 I P I (ms) R 21 17.4 15 28 20 W 21 12.8 16 25 14 64 20 15.8 15 27 20 73 20 15.0 16 28 1 1 P a r t 2: Dur (ms) R 204 8.9 159 243 22 W 230 11.2 1 79 272 1 4 64 252 16.1 171 337 20 73 297 13.1 231 372 1 1 c o n t i n u e d . . . 370 CALL N33 - continued... Measurement Pod Mean C.V. Min Max n Dur, 1st hi R 1 1 4 16.6 60 151 22 part (ms) W 132 16.0 88 166 1 4 64 158 19.6 1 1 2 217 20 73 195 17.4 1 32 255 1 1 Dur, lo part R 54 21.1 23 77 22 (ms) W 195 13.7 138 236 1 4 64 48 18.0 27 64 20 73 52 15.7 39 64 1 1 Dur, 2nd hi R 35 26.8 21 54 22 part (ms) W 35 24.2 17 46 1 4 64 44 30.3 21 73 20 73 49 15.7 37 60 1 1 SBI, 1st peak R 1 793 8.8 1 521 2059 22 (Hz) W 1773 7.2 1 538 1 962 1 4 64 1696 8.8 1 48 1 1912 20 73 1709 9.6 1 439 2007 1 1 SBI , dip (Hz) R 712 14.3 578 1024 22 W 668 9.1 589 778 1 4 64 680 9.4 542 791 20 73 621 7.0 570 715 1 1 SBI , 2nd peak R 1 1 42 11.4 853 1 373 22 (Hz) W 1 045 1 1 .7 817 1 308 1 4 64 962 1 1.9 789 1220 20 73 978 11.0 759 1131 1 1 Part 3: Dur (ms) R 486 16.2 343 647 22 W 432 11.3 316 517 14 64 472 20. 1 341 694 20 73 405 16.4 263 502 1 1 SBI, sta r t (Hz) R 925 15.3 621 1 162 22 W 833 14.5 703 1068 14 64 778 10.2 625 937 20 73 750 10.5 646 869 1 1 cont inued. 371 CALL N33 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n SBI, end (Hz) R 2997 11.3 2266 3774 22 W 2892 12.0 2305 3504 1 4 64 2550 13.2 1 922 3065 20 73 2683 16.4 2062 3501 1 1 P a r t 4: Dur (ms) R 1 48 20. 1 1 1 9 210 7 W 109 25.2 81 1 47 4 64 173 1 73 1 64 19.0 133 235 9 f , SB 1, peak R 5379 18.2 3993 7066 20 (Hz) W 4663 8.4 4000 5279 7 64 4352 14.9 3943 5422 5 73 4455 17.9 321 1 5619 1 1 f, SB 1, end R 2718 16.1 2320 3335 7 (Hz) W 2985 9.0 2723 3326 4 64 4056 1 73 2590 3.8 2492 2763 9 Tone: f , s t a r t (Hz) R 5288 27.3 2088 7281 1 5 W 4527 32.9 1 957 5940 10 64 4041 25.8 2389 6324 18 73 2896 27.5 2028 3987 7 372 CALL N33 - Measurement Comparisons Measurement R vs W R vs 64 W vs 64 D u r a t i o n (ms) ns ns ns P a r t 1: Dur (ms) ns ns ns IPI (ms) ns ns ns P a r t 2: Dur (ms) ns <0.001 ns Dur, 1st h i (ms) ns <0.001 ns Dur, l o (ms) <0.001 ns <0.001 SBI, 1st peak (Hz) ns ns ns SBI, d i p (Hz) ns ns ns SBI, 2nd peak (Hz) ns <0.001 ns P a r t 3: Dur (ms) ns ns ns SBI, s t a r t (Hz) ns <0.001 ns SBI, end (Hz) ns <0.01 ns P a r t 4: Dur (ms) ns f, SB1, peak (Hz) ns ns ns f, SB1, end ns Tone: f , s t a r t (Hz) ns ns ns CALL N34 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) R 1320 17.9 987 1768 1 1 W 1335 12.8 1 022 1 498 8 64 1324 13.3 1086 1689 1 4 73 1085 6.6 1 034 1 136 2 P a r t 1: Dur (ms) R 778 29.8 434 1215 1 1 W 799 23.8 433 961 8 64 673 24 .4 420 1012 14 73 457 7.1 434 480 2 I P I (ms) R 20 12.0 16 25 1 1 W 21 9.8 19 26 8 64 19 8.7 17 23 13 73 21 6.7 20 22 2 P a r t 2: Dur (ms) R 421 8.0 335 462 1 1 W 423 6.0 396 480 8 64 451 21 .7 236 642 14 73 488 7.0 464 512 2 cont i n u e d . 374 CALL N34 - cont inued... Measurement Pod Mean C.V. Min Max n SBI , start (Hz) R 1226 16.3 960 1 636 1 1 W 989 22.0 799 1392 8 64 1285 13.5 993 1643 1 4 73 946 4.0 920 973 2 SBI , peak (Hz) R 1492 5.6 1390 1698 1 1 W 1 434 3.6 1381 1519 8 64 1416 17.1 628 1717 1 4 73 1380 1.5 1 366 1395 2 Part 3: Dur (ms) R 120 18.5 85 161 1 1 W 1 12 13.6 96 143 8 64 199 48.9 127 515 14 73 1 40 4.0 1 36 1 44 2 SBI , start (Hz) R 671 3.9 626 722 1 1 W ' 669 7.1 628 771 8 64 673 10.6 586 891 14 73 642 5.1 619 665 2 SBI , end (Hz) R 955 13.2 827 1 268 1 1 W 905 17.0 712 1 185 8 64 923 12.7 692 1 093 14 73 922 4. 1 895 949 2 C a l l N35 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) R 1056 16.5 648 1 275 10 W 612 5.1 571 668 6 P a r t 1: Dur (ms) R 86 18.1 58 109 10 W 68 5.0 63 72 5 SBI (Hz) R 129 21 .5 96 179 10 W 122 17.8 91 144 6 P a r t 2: Dur (ms) R 143 13.8 124 182 10 W 90 22.7 61 118 5 SBI (Hz) R 303 11.6 249 357 10 W 299 1 1.9 255 350 5 P a r t 3: Dur (ms) R 202 16.5 1 23 238 10 W 167 15.5 122 185 5 SBI (Hz) R 1790 10.5 1483 2108 10 W 1982 9.2 1 797 2232 6 c o n t i n u e d . . . 376 CALL N35 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 4: Dur (ms) R W 1 15 1 1 7 26.3 32.6 85 84 182 183 9 5 SBI (Hz) R W 698 842 10.1 10.4 623 741 795 945 8 5 P a r t 5: Dur (ms) R W 518 1 57 34.3 37.7 189 65 746 228 9 5 SBI, s t a r t (Hz) R W 2207 2376 16.8 7.4 1659 2103 2771 2525 10 5 SBI , end (Hz) R W 2534 3024 11.6 8.6 2026 2588 2836 3273 10 5 377 CALL N38 P a r t : 8 -kHz 4 -: Measurement Pod Mean C.V. Min Max D u r a t i o n (ms) P a r t U Dur (ms) SBI (Hz) P a r t 2: Dur (ms) SBI (Hz) G 576 15.8 412 707 9 G 244 23.5 181 330 9 G 827 8.7 739 978 9 G 331 17.2 231 412 9 G 314 18.5 229 395 7 378 CALL N39 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) 11 1 305 15.0 223 381 1 2 P a r t 1: Dur (ms) 11 1 97 21.4 70 150 12 SBI (Hz) 11 1 845 9.5 716 977 1 1 P a r t 2: Dur (ms) 11 1 208 18.8 122 267 12 SBI, s t a r t (Hz) 11 1 1693 22.9 896 2318 12 SBI, end (Hz) 11 1 2953 25.3 1857 4523 12 3 7 9 CALL N40 P a r t : Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) G 401 30.5 229 695 1 2 SBI , s t a r t (Hz) G 563 21.8 390 803 12 SBI , peak (Hz) G 715 12.2 61 1 870 1 2 SBI , end (Hz) G 535 26. 1 293 766 1 2 IPI (ms) G 23 13.6 18 28 1 2 380 CALL N41 P a r t : 8 — kHz 1.0 s Measurement Pod Mean C.V. Min Max n Durat i o n (ms) G 789 6.6 713 876 15 11 1 705 23.5 532 957 6 P a r t 1: Dur (ms) G 134 10.3 109 163 15 I 1 1 137 17.9 1 1 7 179 6 SBI (Hz) G 120 25.5 72 183 15 I 1 1 120 17.7 96 1 44 6 Dur, gap between G 84 28.7 49 128 15 P t s . 1 & 2 (ms) 11 1 116 50.3 59 224 6 Dur, gap between G 1 26 28.0 64 189 15 P t s . 2 & 3 (ms) 11 1 139 38.3 92 235 6 P a r t 3: Dur (ms) G 65 15.1 48 84 15 I 1 1 60 22.6 43 82 6 SBI (Hz) G 139 25.3 85 191 1 5 I 1 1 131 42.4 62 204 6 Dur, gap between G 72 19.1 45 97 15 P t s . 3 & 4 (ms) 11 1 79 26.2 51 109 6 c o n t i n u e d . 381 CALL N41 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 4: Dur (ms) G 308 15.3 232 409 1 5 I 1 1 172 47.9 63 272 6 SBI, s t a r t (Hz) G 509 18.7 393 757 1 5 I 1 1 654 14.0 507 781 6 SBI, end (Hz) G 854 6.8 752 944 1 5 I 1 1 858 22.8 546 1115 6 P a r t : 8 -kHz 4-CALL N42 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) P a r t 1: Dur (ms) R 64 R 64 1272 1265 419 407 7.3 1089 4.0 1233 22.9 18.5 281 322 1 460 1323 614 464 20 3 20 3 c o n t i n u e d . 382 CALL N42 - c o n t i n u e d Measurement Pod Mean C.V. Min Max n I P I (ms) R 24 19.4 1 6 30 14 64 21 18.9 1 7 25 3 P a r t 2: Dur (ms) R 228 26.6 151 354 20 64 245 24.3 177 287 3 SBI (Hz) R 1513 6.2 1 351 1693 20 64 1 427 1 .4 1 405 1443 3 P a r t 1' Dur (ms) R 625 17.9 444 749 20 64 613 17.4 533 734 3 SBI , s t a r t (Hz) R 677 10.5 563 788 20 64 734 5.7 689 772 3 SBI , peak (Hz) R 986 9.6 735 1 1 30 20 64 1076 9.3 994 1 187 3 SBI , d i p (Hz) R 572 14.9 451 766 20 64 596 5.8 557 620 3 SBI , end (Hz) R 782 15.7 609 1110 20 64 780 15.7 669 91 1 3 383 CALL N43 0.5 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) R 345 12.7 281 435 20 W 293 8.9 269 331 5 64 445 18.3 388 503 2 73 399 1 SBI, s t a r t (Hz) R 776 10.6 657 984 20 W 726 7.0 681 809 5 64 91 1 3.0 892 931 2 73 691 1 SBI, end (Hz) R 745 7.8 536 817 20 W 770 7.9 709 859 5 64 781 4.1 759 804 2 • 73 710 1 Tone: f , s t a r t (Hz) R 1607 30.0 931 2986 20 W 1416 23.7 1 022 1830 5 64 1902 11.3 1750 2054 2 73 1376 1 f, peak (Hz) R 6307 2.6 5969 6564 20 W 6470 1.7 6346 6636 5 64 6466 2.6 6348 6585 2 73 5596 1 f, end (Hz) R 5607 2.0 5380 5744 20 W 5700 2.8 5470 5850 5 64 5620 2.2 5531 5709 2 73 4989 1 384 CALL N44 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) G 1396 14.0 1 054 1736 23 P a r t 1: Dur (ms) G 118 29.6 68 219 23 SBI (Hz) G 1 26 19.0 58 171 23 P a r t 2: Dur (ms) G 859 17.6 592 1218 23 SBI, s t a r t (Hz) G 675 24.2 434 1015 23 SBI, peak (Hz) G 1914 10.1 1501 2140 23 SBI, end (Hz) G 1 1 57 10.8 901 1479 23 P a r t 3: Dur (ms) G 418 16.8 235 571 23 SBI, s t a r t (Hz) G 479 16.8 314 607 23 SBI, end (Hz) G 497 14.9 314 579 23 385 CALL N45 P a r t : Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) G 11 1 208 238 47.9 87. 414 12 1 SBI, s t a r t (Hz) G I 1 1 1 1 72 1086 6.9 1025 1315 12 1 SBI, end (Hz) G 1201 6.8 1076 1 305 1 2 111 1211 1 386 CALL N46 P a r t : , r — kHz Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) G 356 8.6 320 383 4 11 1 427 7.9 349 488 1 5 P a r t 1 : Dur (ms) G 241 2.8 238 252 4 I 1 1 355 6.3 305 389 15 SBI, s t a r t (Hz) G 578 22.4 388 664 4 I 1 1 563 17.6 433 762 15 SBI, end (Hz) G 228 1 1 .2 1 92 251 4 11 1 280 11.6 240 328 1 5 Dur, gap between G 84 31.0 56 1 13 4 P t s . 1 & 2 (ms) 11 1 47 47.2 16 86 15 P a r t 2: Dur (ms) G 30 13.6 25 35 4 11 1 24 23.3 18 39 15 f , peak emphasis (Hz) G 799 14.3 681 953 4 I 1 1 1059 13.1 818 1233 15 387 CALL N47 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) A1 838 17.7 612 1243 26 P a r t 1: Dur (ms) A1 385 34. 1 217 742 26 SBI (Hz) A1 141 12.8 105 176 26 P a r t 2: Dur (ms) A1 453 24.2 225 693 26 SBI, s t a r t (Hz) A1 1 139 18.4 700 1477 26 SBI, end (Hz) A1 2390 16.9 1800 3338 26 Tone: f , s t a r t (Hz) A1 4762 15.8 2959 6324 24 CALL N48 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) G 505 4.5 481 526 3 I 1 1 640 19.5 488 787 9 P a r t 1 : Dur (ms) G 175 5.0 166 183 3 I 1 1 180 16.3 1 29 219 9 SBI, s t a r t (Hz) G 797 16.0 652 891 3 I 1 1 71 1 27.8 446 1 002 9 SBI, end (Hz) G 2764 9.6 2492 3020 3 I 1 1 301 1 10.7 2425 3360 9 P a r t 2: Dur (ms) G 109 1 1 .9 96 122 3 11 1 118 23.0 82 180 9 SBI (Hz) G 1846 52.3 731 2421 3 I 1 1 1704 39.9 692 2357 9 cont i n u e d . 389 CALL N48 - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 3: Dur (ms) G 220 12.3 205 252 3 11 1 340 30.0 239 500 9 SBI , peak (Hz) G 1279 19.7 1018 1 520 3 I 1 1 1 454 18.0 1018 1773 9 SBI , end (Hz) G 970 14.8 822 1 109 3 I 1 1 674 30.5 387 1014 9 390 CALL N50 P a r t : 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) R 146 15.1 124 200 10 W 167 11.4 1 54 181 2 64 180 1 73 207 1 SBI, s t a r t (Hz) R 849 33.6 483 1 199 10 W 498 41.7 351 645 2 64 816 1 73 603 1 SBI, peak (Hz) R 1478 6.2 1275 1579 10 W 1402 7.4 1329 1 475 2 64 1522 1 73 1517 1 SBI, end (Hz) R 1489 5.2 1381 1633 10 W 1414 3.8 1376 1453 2 64 1448 1 73 1545 — — — — — — " ~ — 1 391 CALL N51 P a r t : 8 -kHz 4 -1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) R 828 27.8 385 1212 1 1 W 576 1 .8 565 585 3 73 624 17.0 51 1 721 3 SBI, s t a r t (Hz) R 182 32.8 85 273 1 1 W 145 17.9 121 173 3 73 224 23.5 170 275 3 SBI, end (Hz) R 1281 15.6 1063 1 751 1 1 W 1355 4.0 1 308 1414 3 73 1 193 10.7 1068 1323 3 392 SOUTHERN COMMUNITY CALLS: P a r t : 8-kHz 4 -CALL S1 2 3 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 884 38.5 527 1986 52 MD 736 6.9 649 8 1 5 9 Sh 803 21.6 500 955 6 Part 1: Dur (ms) J 629 44.5 341 1464 48 MD 596 7.3 526 678 9 Sh 509 24.4 306 667 6 SBI, s t a r t (Hz) J 1020 6.1 885 1 1 78 52 MD 1 184 4.2 1099 1245 9 Sh 1 162 9.1 1 023 1329 6 co n t i n u e d . . 393 CALL SI - c o n t i n u e d , Measurement Pod Mean C.V. Min Max n SBI , end (Hz) J 1 065 11.6 880 1515 52 MD 1 195 4.6 1 1 22 1 275 9 Sh 1 140 7.0 1 033 1 224 6 P a r t 2: Dur (ms) J 99 34.5 42 234 48 MD 77 21.9 45 100 9 Sh 151 52.2 95 308 6 SBI , s t a r t (Hz) J 693 19.4 546 1 370 48 MD 1 027 5.5 954 1113 9 Sh 771 11.0 669 91 1 6 SBI , end (Hz) J 573 13.4 403 733 48 MD 1 026 8.8 816 1118 9 Sh 523 10.1 461 589 6 P a r t 3: Dur (ms) J 1 1 8 32.7 63 295 48 MD 64 16.0 46 77 9 j Sh 142 45.0 41 219 6 SBI , end (Hz) J 413 13.0 270 550 52 MD 735 10.1 615 810 9 Sh 447 5.6 418 483 6 394 CALL S 2 i P a r t : 8 -kHz 4 -r~ • 1 1 0 0.5 1 .0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 844 23.8 575 1615 34 MD 954 22.3 745 1 500 21 Sh 912 11.3 690 1 168 23 P a r t 1: Dur (ms) J 577 31 .5 325 1 308 34 MD 499 39.6 343 1 062 21 Sh 572 14.1 447 746 23 SBI, s t a r t (Hz) J 1 176 25.8 605 1 737 34 MD 1767 10.7 1459 2026 9 Sh 1394 13.0 1 021 1733 9 SBI, d i p (Hz) J 1012 17.4 624 1 387 34 MD 1 187 38.6 548 1876 20 Sh 1296 13.5 857 1542 23 SBI, end (Hz) J 1929 9.5 1605 2243 34 MD 21 74 9.2 1831 2474 20 Sh 2051 7.9 1803 2359 23 c o n t i n u e d . . . 395 CALL S 2 i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 2: Q Dur (ms) J 141 14.1 108 191 34 MD 325 22.7 212 464 21 Sh 239 30.9 1 35 407 23 SBI, s t a r t (Hz) J 497 18.0 323 694 34 MD 607 12.0 407 743 20 Sh 499 12.0 379 653 23 SBI , d i p (Hz) J 459 15.2 359 692 34 MD 627 10.2 500 724 20 Sh 518 9.3 459 660 23 SBI, end (Hz) J 2118 17.9 1 364 2881 34 MD 2589 22.2 1 520 3365 21 Sh 2523 21.2 1 555 3852 23 P a r t 3: Dur (ms) J 1 25 27.0 82 223 34 MD 129 38.7 62 259 21 Sh 1 00 23.5 52 1 52 23 SBI , end (Hz) J 1017 10.4 830 1300 34 MD 1744 19.5 822 2110 20 Sh 1141 13.7 824 1391 23 Tone : f , s t a r t (Hz) J 4683 13.7 3772 6484 29 MD 4254 30.9 2561 5750 4 Sh 4258 6.5 3994 4848 9 396 CALL S 2 i - Measurement Comparisons Measurement J vs MD J vs Sh MD vs Sh D u r a t i o n (ms) ns ns ns P a r t 1 : Dur (ms) ns ns ns SBI, s t a r t (Hz) -- — --SBI, d i p (Hz) ns <0.001 ns SBI, end (Hz) <0.001 ns ns P a r t 2: Dur (ms) <0.001 <0.001 <0.001 SBI, s t a r t (Hz) <0.001 ns <0.001 SBI, d i p (Hz) <0.001 <0.01 <0.001 SBI, end (Hz) <0.01 <0.05 ns P a r t 3: Dur (ms) ns <0.05 <0.05 SBI, end (Hz) <0.001 ns <0.001 Tone: f , s t a r t ns ns ns CALL S 2 i i J r 0 r " 0.5 j 1 .0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 840 15.2 642 1 040 1 3 MD 839 14.9 637 980 9 P a r t j _ : Dur (ms) J 572 27.5 370 965 13 MD 423 20.3 308 531 9 SBI , s t a r t (Hz) J 1229 20.7 733 1 587 1 3 MD 1944 11.7 1783 2105 2 SBI , d i p (Hz) J 1057 15.1 622 1 266 13 MD 966 48. 1 435 1780 9 SBI , end (Hz) J 2063 9.1 1770 2400 13 MD 2264 18. 1 1863 2835 9 P a r t 2: Dur (ms) J 133 17.5 88 172 13 MD 190 29.7 1 10 252 9 SBI , s t a r t (Hz) J 519 13.6 359 615 13 MD 616 9.1 488 676 9 SBI , d i p (Hz) J 466 35.5 270 958 13 MD 634 12.6 494 722 9 cont i n u e d . 398 CALL S 2 i i -- c o n t i n u e d . . • Measurement Pod Mean C.V. Min Max n P a r t 2: SBI, end (Hz) J 21 59 13.6 1490 2461 1 1 MD 2769 21 .8 2104 3982 9 P a r t 1' Dur (ms) J 1 66 33.7 109 306 1 2 MD 225 13.1 182 280 9 SBI , peak (Hz) J 1 138 19.8 684 1600 1 3 MD 2398 18.3 1824 3001 9 SBI , end (Hz) J 878 16.4 681 1076 13 MD 1 546 19.2 1 226 21 24 9 Tone : s t a r t (Hz) J 441 3 10.3 3693 5056 10 399 CALL S 2 i i i Measurement Pod Mean C.V. Min Max n Duration (ms) L 617 23.8 384 982 26 73 741 1.9 731 751 2 Part 1: Dur (ms) L 466 29.5 216 873 26 73 624 2.5 613 635 2 Time to upsweep (ms) L 304 32.0 1 94 613 24 73 356 4.8 344 368 2 SBI, s t a r t (Hz) L 554 9.9 464 688 26 73 435 24.7 359 51 1 2 SBI, end (Hz) L 2649 10.1 2358 3686 25 73 2769 6.0 2651 2887 2 cont inued... 400 CALL S 2 i i i - c o n t i n u e d . . . Measurement Pod Mean C.V. Min Max n P a r t 2: Dur (ms) L 73 150 1 1 7 30.7 1 .2 79 116 268 118 26 2 SBI, s t a r t (Hz) L 73 606 548 18.8 6.7 408 522 828 574 26 2 SBI, end (Hz) L 73 542 522 20.4 20.6 336 446 793 598 26 2 Tone: f , s t a r t (Hz) L 73 5557 6247 4.5 6.9 5103 5943 6033 6551 25 2 f , end (Hz) L 73 6419 6791 11.1 12.2 5398 6207 7813 7375 24 2 401 CALL S3 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n Duration (ms) J 1 195 24.3 598 1649 21 MD 1079 3.6 1025 1 1 35 10 Part 1 : Dur (ms) J 964 30.4 433 1 449 21 MD 909 3.8 872 952 10 SBI, s t a r t (Hz) J 1068 4.0 994 1 1 66 21 MD 955 4.6 868 1028 10 SBI, end (Hz) J 1068 6.6 972 1245 21 MD 898 5.6 831 982 10 Part 2: Dur (ms) J 231 17.5 165 313 21 MD 169 6.8 1 53 189 10 SBI, s t a r t (Hz) J 453 6.3 395 500 21 MD 408 5.0 377 431 10 SBI, end (Hz) J 455 6.8 396 516 21 MD 400 6.7 356 435 10 402 CALL S4 P a r t : 8 -kHz 4 -1.0 s Measurement Pod Mean C.V. Min Max n Duration (ms) Part J_: Dur (ms) IPI, s t a r t (ms) Part 2: Dur (ms) SBI (Hz) J 758 26.8 484 1269 29 J 188 39.6 87 425 29 J 52 24.0 30 75 29 J 570 26.8 380 968 29 J 159 11.5 120 191 29 403 CALL S5 P a r t : kHz 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 81 25. 1 45 1 16 16 Sh 123 8.7 107 130 4 SBI (Hz) J 294 9.2 235 331 16 Sh 364 3.5 351 381 4 404 Measurement Pod Mean C.V. Min Max n Duration (ms) J 466 17.4 315 580 21 SBI, start (Hz) J 950 15.1 686 1 176 21 SBI, peak (Hz) J 1033 12.5 861 1 336 21 SBI, end (Hz) J 251 16.4 170 343 21 405 CALL S7 P a r t : i . — r 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 905 15.7 706 1 246 23 P a r t 1 : Dur (ms) J 607 22.7 427 957 23 Time t o down-sweep (ms) J 470 28.8 278 839 23 SBI, s t a r t (Hz) J 1 023 4.7 933 1 1 37 23 SBI, end (Hz) J 613 12.7 452 739 23 Dur, gap between P t s . 1 & 2 (ms) J 135 29.9 74 283 23 P a r t 2: Dur (ms) J 163 15.3 122 216 23 SBI, s t a r t (Hz) J 444 12.1 375 574 23 SBI, end (Hz) J 393 7.8 348 451 23 406 CALL S8 i & i i P a r t : . . . 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 221 63.4 78 459 17 L 501 13.1 399 642 14 P a r t 1: Dur (ms) J 123 98.3 1 4 337 1 7 L 409 16.5 280 523 14 I P I , s t a r t (ms) J 34 38.1 22 61 7 L 29 18.7 21 42 14 P a r t 2: Dur (ms) J 98 37.5 49 178 17 L 92 14.5 73 119 1 4 SBI, s t a r t (Hz) J 2542 15.6 1653 3223 17 L 734 9.4 667 924 1 4 SBI, end (Hz) J 6432 19.0 4099 7854 17 L 5495 18.3 4300 7330 14 N.B.: Subtype S 8 i g i v e n by J pod, and S 8 i i by L pod. CALL S9 Measurement Pod Mean C.V. Min Max D u r a t i o n (ms) J 1069 8.7 952 1249 P a r t 1: Dur (ms) J 636 16.5 502 803 SBI, s t a r t (Hz) J 1 189 4.3 1 136 1 282 SBI, end (Hz) J 1 170 4.3 1 1 07 1265 P a r t 2: Dur (ms) J 173 1 1.9 131 200 SBI (Hz) J 1 046 5.6 975 1 151 P a r t 3: Dur (ms) J 258 13.0 214 315 SBI (Hz) J 937 4.6 882 1 002 408 CALL S10 1.0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 958 9.8 887 1 1 03 5 K 1 035 4.4 992 1 083 3 L 1610 17.6 1 160 1975 6 P a r t 1 : Dur (ms) J 369 14.6 305 431 5 K 428 13.2 373 486 3 L 451 15.3 356 519 6 S B I , s t a r t (Hz) J 1 02 22.7 72 135 5 K 107 22.0 84 131 3 L 94 20.0 73 127 6 S B I , end (Hz) J 229 38.6 177 387 5 K 175 6.4 162 182 3 L 196 18.6 149 230 6 P a r t 2: Dur (ms) J 589 22.7 474 798 5 K 606 9.5 544 657 3 L 1 159 20.7 804 1 530 6 Dur, p u l s e s (ms) J 119 14.8 73 210 15 K 113 34.2 67 180 9 r 1 37 34.3 68 284 18 cont i n u e d . . . 409 CALL S10 - c o n t i n u e d . . Measurement Pod Mean C.V. Min Max n Dur, I P I ' s (ms) J 77 8.1 49 1 20 15 K 89 38.7 48 1 59 9 L 132 38.6 77 233 1 1 P a r t : 8-kHz 4 -CALL S12 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 954 25.4 726 1549 1 4 P a r t 1: Dur (ms) J 650 36.0 400 1246 14 SBI, s t a r t (Hz) J 1047 6.1 894 1119 1 4 SBI, end (Hz) J 1944 16.3 1 290 251 5 14 P a r t 2: Dur (ms) J 303 12.4 193 353 14 SBI, d i p (Hz) J 539 25.5 440 926 14 SBI, end (Hz) J 1627 20.9 961 2260 14 410 CALL S13 P a r t : 8-kHz f 4-r • a £ — — .. — . * " . * " " • - - -r* ——^ | 0 0.5 1.0 s Measurement Pod Mean C.V. Min Max n P* D u r a t i o n (ms) J 231 17.4 189 329 1 4 <0.001 L 163 15.1 124 222 1 6 73 305 7.4 273 339 7 P a r t 1: Dur (ms) J 126 28.0 98 210 1 4 <0.001 L 63 12.4 48 78 16 73 160 13.4 118 183 7 Dur, l e v e l p a r t J 71 41 .3 38 134 1 4 <0.001 (ms) L 26 22.5 1 7 43 16 73 127 17.7 90 157 7 SBI, s t a r t (Hz) J 2688 10.4 1989 3083 1 4 ns L 2375 16.4 1405 2859 16 73 2791 25.2 1841 3662 7 SBI, mid (Hz) J 3938 3.5 3506 4089 1 4 <0.001 L 3124 3.4 2905 3331 16 73 3179 5.2 2927 3421 7 SBI, end (Hz) J 3863 3.4 3453 3992 1 4 <0.001 L 3140 3.6 2941 3367 16 73 3289 4.4 3124 3528 7 cont inued, 411 CALL S13 - cont inued [. . . Measurement Pod Mean C.V. Min Max n P* P a r t 2: Dur (ms) J 105 14.1 87 1 30 14 ns L 100 19.0 76 144 16 73 1 45 21 .8 93 196 7 SBI, s t a r t (Hz) J 480 16.9 362 678 1 4 ns L 465 15.0 375 595 16 73 597 37. 1 343 1024 7 SBI, d i p (Hz) J 434 16.9 351 618 1 4 ns L 479 12.1 375 559 16 73 591 33. 1 408 967 7 SBI, end (Hz) J 493 17.4 378 661 14 ns L 536 22.4 348 813 16 73 555 37.7 270 924 7 ANOVA comparison between J and L pods o n l y . 412 CALL S14 P a r t : 8 -kHz I 0 1 ' 0.5 1 1.0 s Measurement Pod Mean C.V. Min Max n P* D u r a t i o n (ms) J 539 5.9 518 587 4 MD 635 5.7 567 712 1 4 <0.001 Sh 716 6.7 651 787 13 P a r t 1 : Dur (ms) J 303 11.2 264 347 4 MD 372 8.2 322 416 1 4 <0.01 Sh 439 15.5 352 604 1 4 SBI, s t a r t (Hz) J 266 21.2 215 337 4 MD 331 23.2 245 525 14 ns Sh 304 16.3 227 405 1 4 SBI, mid (Hz) J 512 12.8 454 582 4 MD 631 7.2 576 720 1 4 ns Sh 643 7.3 594 749 1 4 SBI, end (Hz) J 653 6.9 595 693 4 MD 642 6.6 568 705 1 4 ns Sh 684 12.2 583 853 13 P a r t 2: Dur (ms) J 108 11.1 91 121 4 MD 116 13.8 90 1 49 14 <0.001 Sh 148 12.8 122 185 14 c o n t i n u e d . . . 413 CALL S14 - continued... Measurement Pod Mean C.V. Min Max n P* Part 3: Dur (ms) J 1 28 10.7 109 141 4 MD 147 14.3 1 15 196 1 4 ns Sh 1 39 13.3 1 04 1 70 1 3 SBI, start (Hz) J 1721 7.0 1,553 1815 4 MD 2290 6.0 2070 2529 1 4 ns ' Sh 2254 3.8 2128 2400 14 SBI, end (Hz) J 2185 3.3 2089 2247 4 MD 2316 5.1 21 29 2516 14 ns Sh 2284 4.8 21 10 2520 1 3 ANOVA comparison between MD and Sh only. 414 CALL S16 P a r t : 8 -kHz • 4 — i r—-0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) K L 729 1088 31.4 30.6 350 709 1264 1 333 1 5 3 Time t o downsweep (ms) K L 540 857 40.6 29.7 237 564 1 102 1023 1 5 3 SBI, s t a r t (Hz) K L 1 1 38 1 258 6.2 7.9 962 1 1 47 1 226 1 336 15 3 SBI, s t a r t of downsweep (Hz) K L 1 1 23 1 228 10.3 6.6 881 1 160 1270 1317 15 3 SBI, end (Hz) K L 950 984 9.7 10.5 732 870 1114 1071 1 5 3 415 CALL S17 P a r t : 8 -kHz 4 - ••: > m -•«1 r - i "r. 0.5 1.0 s Measurement Pod Mean C.V. Min Max D u r a t i o n (ms) P a r t U Dur (ms) S B I , s t a r t (Hz) SBI, mid (Hz) S B I , end (Hz) P a r t 2: Dur (ms) S B I , end (Hz) K 857 11.0 743 980 7 L 870 --- --- 1 K L 609 717 K 1219 L 1201 K 1216 L 1270 K 1 1 58 L 1 177 15.9 483 727 3.7 1159 1283 3.8 1166 1297 5.2 1076 1231 K 247 14.2 184 292 L 153 K 1223 2.9 1187 1292 L 1262 7 1 7 1 7 1 7 1 7 1 7 1 416 CALL SI 8 0 0. 5 1.0 s Measurement Pod Mean C.V. Min Max n P ' C h i r p s : N o . / c a l l L 73 3 3 41.6 18.1 0 2 4 4 26 1 5 Dur (ms) L 73 80 87 17.5 14.9 47 66 97 1 16 23 30 ns f, s t a r t (Hz) L 73 1745 231 2 18.1 9.9 1208 1980 2479 3001 23 30 <0.001 f, end (Hz) L 73 4463 4400 8.3 5.2 3321 4083 4996 5008 23 30 ns P a r t 1: Dur (ms) L 73 418 422 21.6 20.9 256 342 568 597 16 1 1 ns SBI, s t a r t (Hz) L 73 377 383 8.6 9.6 327 332 427 455 16 1 1 ns SBI, end (Hz) L 73 703 757 10.3 6.9 575 685 810 846 16 1 1 ns 417 CALL S19 P a r t : 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n p Duration (ms) L 730 22. 1 330 1099 35 ns 73 844 28.9 559 1475 15 Pulsed p a r t : Dur (ms) L 485 28. 1 169 833 35 <0.01 73 625 23.4 390 1 048 15 SBI, s t a r t L 827 23.5 471 1365 35 <0.001 (Hz) 73 1 103 13.0 812 1368 15 SBI, end L 2004 23.5 1303 31 28 35 ns (Hz) 73 2056 17.5 1468 2816 15 Tone: Dur (ms) L 682 24.8 240 1063 35 ns 73 729 36.7 354 1367 15 f, s t a r t (Hz) L 4874 2.9 4562 51 27 35 ns 73 4906 5.0 4483 5447 15 f, end (Hz) L 5885 11.1 4976 7751 35 ns 73 5655 10.0 4848 6828 1 5 418 Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) L 428 24. 1 294 565 1 1 73 585 10.7 509 733 12 P a r t 1: Dur (ms) L 128 35.6 79 21 1 1 4 73 152 24.3 92 199 1 2 SBI (Hz) L 127 14.7 108 174 1 4 73 96 15.7 72 1 1 7 10 P a r t 2: Dur (ms) L 299 23.8 196 417 1 1 73 433 1 1 .9 381 556 12 Dur, l e v e l p a r t L 79 56.6 42 177 14 (ms) 73 134 48.5 71 300 12 SBI, s t a r t (Hz) L 1029 21 .8 806 1628 1 4 73 908 13.0 720 1 129 1 2 SBI, mid (Hz) L 2356 14.8 1515 2669 14 73 2656 4.8 2442 2824 1 2 SBI, end (Hz) L 2442 15.7 1694 2975 1 1 73 2721 5.1 2421 2909 12 c o n t i n u e d . . . 419 CALL S22 - c o n t i n u e d Measurement Pod Mean C.V. Min Max n Tone: f, s t a r t (Hz) L 4388 17.6 3064 5546 1 4 73 4028 10.8 3252 4745 1 1 f, l e v e l p a r t (Hz) L 5798 7.6 4961 6579 14 73 5685 8.7 4607 6436 1 1 f, end (Hz) L 5879 7.4 5062 6696 1 4 73 5744 7.4 4801 6338 1 1 P a r t : 8 -kHz 4--CALL S31 1 0 " J 0.5 T 1.0 mmmmmm s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) L 481 26.5 338 738 23 SBI, s t a r t (Hz) L 148 28.2 62 238 23 SBI, end (Hz) L 706 27.6 382 1 073 23 420 CALL S33 P a r t : 1 2 kHz Measurement Pod Mean C.V. Min Max n Duration (ms) L 73 Part J_: Dur (ms) L 73 Part 2: Dur (ms) L 73 Dur, l o p a r t s L (ms) 73 Dur, h i p a r t s L (ms) 73 f, l o p a r t s L (Hz) 73 f, h i p a r t s L (Hz) 73 566 20. 4 440 825 14 586 60. 3 321 1079 6 1 66 21 . 5 93 239 15 237 59. 5 1 20 449 6 396 27. 0 299 654 1 4 349 61 . 4 195 630 6 66 25. 7 29 1 08 34 70 9. 7 58 79 10 85 18. 5 44 107 24 93 15. 1 77 110 6 866 18. 0 556 1099 37 879 5. 9 813 967 10 1695 6. 7 1470 1869 34 1685 5. 8 1551 1805 10 421 CALL S36 P a r t : kHz Measurement Pod Mean C.V. Min Max n Duration (ms) L 951 11.0 750 1 1 35 21 Part 1: Dur (ms) L 302 12.7 223 378 28 SBI, s t a r t (Hz) L 900 6.0 779 981 28 SBI, end (Hz) L 848 6.7 750 955 28 Part 2: Dur (ms) L 324 20.3 200 443 19 SBI, s t a r t (Hz) L 333 16.4 244 452 21 SBI, end (Hz) L 214 38.8 86 402 21 Tone: Dur (ms) L 932 11.6 722 1 182 28 f, s t a r t (Hz) L 4751 9.5 3469 5485 27 f, peak (Hz) L 5847 5.9 5371 6603 27 f, min (Hz) L 3847 7.3 3441 4394 27 f, end (Hz) L 5439 2.8 5128 5719 28 422 Measurement Pod Mean C.V. Min Max n Duration (ms) J 609 25.5 380 977 20 Part 1: Dur (ms) J 368 40.6 141 613 17 SBI (Hz) J 45 20.3 35 85 20 Part 2: Dur (ms) J 253 22.2 187 416 17 SBI, s t a r t (Hz) J 488 16.1 367 647 20 SBI, peak (Hz) J 864 26.0 587 1518 20 SBI, end (Hz) J 526 19.4 386 726 20 Tone: f, s t a r t (Hz) J 4605 11.2 3206 51 16 17 f, 1st peak (Hz) J 6098 4.9 5514 6648 17 f, d i p (Hz) J 5226 6.8 4800 5989 17 423 CALL S 3 7 i i 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) L 765 16.7 654 1 042 13 P a r t 1: Dur (ms) L 444 26.6 332 635 1 1 SBI (Hz) L 77 18.7 48 95 13 P a r t 2: Dur (ms) L 389 34. 1 298 685 13 SBI, s t a r t (Hz) L 1056 14.7 905 1462 13 SBI, end (Hz) L 795 6.4 719 909 13 Tone: f, s t a r t (Hz) L 5871 5.8 5135 6254 1 1 f, 1st peak (Hz) L 6657 2.7 641 1 6959 1 1 f, d i p (Hz) L 5963 4.4 5577 6348 1 1 424 CALL S40 P a r t : 0 0.5 1.0 s Measurement Pod Mean C.V. Min Max n Duration (ms) L 601 14.6 519 843 18 Part 1: Dur (ms) L 1 1 1 34.5 19 205 18 IPI, s t a r t (ms) L 17 30.8 5 26 18 Part 2: Dur (ms) L 490 15.1 410 679 18 SBI, s t a r t (Hz) L 580 13.0 421 661 18 SBI, peak (Hz) L 1118 9.9 705 1223 18 SBI, mid (Hz) L 659 1 1.9 51 1 770 18 SBI, end (Hz) L 283 14.3 206 345 18 425 CALL S41 P a r t : Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) J 1318 17.0 904 1731 19 P a r t 1 : Dur (ms) J 213 47.3 42 380 19 SBI (Hz) J 102 18.0 71 1 45 19 P a r t 2: Dur (ms) J 538 23.4 365 776 19 SBI, s t a r t (Hz) J 1037 24.5 439 1 380 19 SBI, peak (Hz) J 21 18 10.4 1 539 2638 19 SBI, end (Hz) J 1 164 18.8 754 1534 19 P a r t 3: Dur (ms) J 566 23.6 302 761 19 SBI, s t a r t (Hz) J 379 9.6 31 1 441 19 SBI, end (Hz) J 361 8.4 31 1 403 19 Tone: f , s t a r t (Hz) J 5208 11.8 4039 6196 19 426 CALL S42 P a r t : 8 kHz fc--. ate 0.5 1.0 s Measurement Pod Mean C.V. Min Max Duration (ms) Part 1: Dur (ms) SBI (Hz) Tone: f , s t a r t (Hz) f, at end of Pt. 1 (Hz) f, end (Hz) J 898 L 775 73 730 J L 73 J L 73 251 287 375 723 761 767 J 4142 L 4227 73 4355 J 4490 L 4757 73 4820 J 7475 L 7352 73 18.3 12.8 37.9 28. 1 5.0 6.4 2.3 5.5 4.4 2.6 2.3 0.3 618 705 1 46 239 645 726 3983 3977 4197 4651 7238 7329 1 261 889 566 380 794 817 4345 4441 4878 4890 7903 7368 26 3 1 26 3 1 26 3 1 26 3 1 26 3 1 26 3 427 CALL S44 Measurement Pod Mean C.V. Min Max n Duration (ms) J 631 16.7 469 893 29 Part 1 : Dur (ms) J 183 31.6 70 326 29 IPI (ms) J 30 22.8 21 55 29 Part 2: Dur (ms) J 62 25.9 27 98 29 SBI (Hz) J 610 16.0 399 772 29 Part 3: Dur (ms) J 385 24.4 236 603 29 SBI, s t a r t (Hz) J 648 17.3 351 800 29 SBI, mid (Hz) J 1009 8.5 833 1219 29 SBI, end (Hz) J 588 21 .5 352 1031 29 428 TRANSIENT COMMUNITY CALLS: Measurement Pod Mean C.V. Min Max n Duration (ms) 04 702 30.7 501 930 3 X 571 18.0 444 714 8 Y 803 22.3 514 957 5 Time to peak SBI (ms) 04 691 29.6 501 908 3 X 541 20.4 41 1 708 8 Y 779 20.2 516 890 5 SBI, s t a r t (Hz) 04 401 16.5 334 466 3 X 372 11.6 322 433 8 Y 397 8.2 354 439 5 SBI, peak (Hz) 04 726 7.6 675 785 3 X 658 16.9 485 819 8 Y 622 8.6 568 675 5 SBI, end (Hz) 04 679 21 .6 513 788 3 X 620 19.1 445 785 8 Y 581 10.1 513 667 5 429 CALL T2 P a r t : r i i 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) X 901 25.5 636 1040 3 P a r t 1: Dur (ms) X 453 40.7 243 589 3 SBI (Hz) X 163 6.8 151 172 3 P a r t 2: Dur (ms) X 1 15 21.2 91 140 3 SBI (Hz) X 560 2.1 551 573 3 P a r t 3: Dur (ms) X 333 14.7 278 372 3 SBI (Hz) X 2583 4.4 2479 2705 3 430 CALL T3 P a r t : 8 ~ kHz 4-I 0 1 0.5 1 1.0 s Measurement Pod Mean C.V. Min Max n Duration (ms) X 917 7.3 840 1012 7 Part 1: Dur (ms) X 333 19.6 284 474 7 SBI, s t a r t (Hz) X 663 12.7 547 815 7 SBI, mid (Hz) X 1033 3.2 978 1079 7 Part 2: Dur (ms) X 583 9.0 532 679 7 SBI, s t a r t (Hz) X 666 7.2 593 714 7 SBI, peak (Hz) X 788 5.8 742 856 7 SBI, end (Hz) X 388 10.0 345 438 7 431 CALL T4 P a r t : , , r f | 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) X 1392 10.2 1 1 39 1 574 7 P a r t 1: Dur (ms) X 326 20.5 264 407 7 SBI, s t a r t (Hz) X 1012 10.0 877 1 1 39 7 SBI, end (Hz) X 762 21.2 529 1068 7 P a r t 2: Dur (ms) X 842 19.2 555 999 7 SBI, peak (Hz) X 712 7.9 655 825 7 SBI, mid (Hz) X 420 11.3 361 495 7 SBI, end (Hz) X 421 15.3 287 484 7 Tone: f , s t a r t (Hz) X 1759 17.3 1220 2259 7 4 3 2 CALL T5 P a r t : f — , , Measurement Pod Mean C.V. Min Max n Duration (ms) X 1131 5.8 1030 1209 5 Part 1 : Dur (ms) X 1 92 8.3 1 64 202 5 SBI, s t a r t (Hz) X 878 8.8 777 985 5 SBI, peak (Hz) X 1 072 5.3 1024 1 169 5 Part 2: Dur (ms) X 823 5.9 763 871 5 SBI, s t a r t (Hz) X 749 5.7 687 799 5 SBI, peak (Hz) X 819 7.2 741 886 5 SBI, end (Hz) X 368 5.9 346 391 5 433 CALL T7 P a r t : 8 kHz 4 Measurement Pod Mean C.V. Min Max n D uration (ms) 04 946 9.1 874 1042 3 Y 1087 4. 1 1050 1 1 49 4 SBI, s t a r t (Hz) 04 454 16. 1 378 524 3 y 487 8.4 430 517 4 SBI, peak (Hz) 04 707 4.5 685 744 3 Y 668 4.1 632 695 4 SBI, mid (Hz) 04 467 2.1 456 475 3 Y 409 7.2 369 439 4 SBI, end (Hz) 04 390 3.4 383 406 3 y 353 6.2 330 373 4 Tone: Dur (ms) 04 230 13.3 199 260 3 y 228 8.6 206 249 4 f, s t a r t (Hz) 04 5178 0.6 51 53 5213 3 y 501 1 2.3 4899 5173 4 434 CALL T6 P a r t : 8 - .- - - w / r . 0 0.5 1 . 0 s Measurement Pod Mean C.V. Min Max n D u r a t i o n (ms) X 999 16.9 868 1 190 3 SBI, s t a r t (Hz) X 183 25.0 1 38 230 3 SBI, end (Hz) X 101 16.4 88 120 3 435 CALL T8 P a r t : 8 -kHz 4 -0.5 1.0 s Measurement Pod Mean C.V. Min Max D u r a t i o n (ms) 04 726 Y 1271 P a r t 1 : Dur (ms) SBI, s t a r t (Hz) SBI, end (Hz) P a r t 2: Dur (ms) SBI, s t a r t (Hz) SBI, peak (Hz) SBI, end (Hz) 04 Y 04 Y 04 Y 04 Y 04 Y 264 442 04 2551 Y 2534 04 2656 Y 2539 462 829 634 532 685 640 306 463