@prefix vivo: . @prefix edm: . @prefix ns0: . @prefix dcterms: . @prefix skos: . vivo:departmentOrSchool "Science, Faculty of"@en, "Zoology, Department of"@en ; edm:dataProvider "DSpace"@en ; ns0:degreeCampus "UBCV"@en ; dcterms:creator "Thomas, Barry"@en ; dcterms:issued "2011-04-26T16:09:34Z"@en, "1971"@en ; vivo:relatedDegree "Doctor of Philosophy - PhD"@en ; ns0:degreeGrantor "University of British Columbia"@en ; dcterms:description """My study is directed towards understanding the pattern of evolution taking place among populations of Peromyscus inhabiting the islands of British Columbia. A standard morphological approach, as veil as karyotype and reproductive isolation analyses, have shown that a taxonomic revision of this faunal group is desirable. I have proposed such a revision. A discriminant analysis utilizing morphological measurements reveals the existence of two distinctive phenotypes within the islands surveyed. Breeding studies, involving 78 pairs of insular Peromyscus, indicate that reproductive isolation exists between the two morph groups. Furthermore, when given the choice the large and small morph groups prefer the company of their own type. Extensive phallic variation occurs among island populations but no suggestion of taxonomic relationships are discernible. Karyotype analysis reveals that there are two distinct karyotypic patterns. The karyotype correlates with the two morphotype classifications. The large morph has a high number of metacentric chromosomes and the small morph has a low number. The high metacentric number karyotype is identical to that possessed by the morphologically similar Peromyscus sitkehsis known to inhabit the islands to the north of the.study group. Karyotype variation within each of the tvo major divisions is minimal. I have proposed that the karyotypic differences between these two morphs is significant at the species level. The large morph should be considered as P. sitkensis and the small phenotype should remain as P. maniculatus. The degree and rapidity of evolution within these Peromyscus populations requires a broadening in the scope of some subspecific taxa. Change in subspecific nomenclature has been indicated. Additional studies of Peromyscus upon the adjacent mainland and Vancouver Island are required before meaningful relationships can be expressed between insular and mainland groups at the subspecific level."""@en ; edm:aggregatedCHO "https://circle.library.ubc.ca/rest/handle/2429/33965?expand=metadata"@en ; skos:note "EVOLUTIONARY RELATIONSHIPS AMONG PEROMYSCUS FROM THE GEORGIA STRAIT, GORDON, GOLETAS, AND SCOTT ISLANDS OF BRITISH.COLUMBIA, CANADA by BARRY THOMAS B.A. (1967), M.A. (1968) C a l i f o r n i a Sta.te College at F u l l e r t o n A Thesis Submitted in P a r t i a l Ful f i lment of the Requirements for the Degree of Doctor of Philosophy In the Department of Zoology We accept th i s thesis as conforming tp the required standard THE UNIVERSITY OF BRITISH COLUMBIA JUNE 1971 I n p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r a n a d v a n c e d d e g r e e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l m a k e i t f r e e l y a v a i l a b l e f o r r e f e r e n c e a n d s t u d y . I f u r t h e r a g r e e t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s m a y b e g r a n t e d b y t h e H e a d o f m y D e p a r t m e n t o r b y h i s r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t b e a l l o w e d w i t h o u t m y w r i t t e n p e r m i s s i o n . D e p a r t m e n t T h e U n i v e r s i t y o f B r i t i s h C o l u m b i a V a n c o u v e r 8, C a n a d a D a t e 6> - 2 i - 7/ ABSTRACT My st u d y i s d i r e c t e d towards u n d e r s t a n d i n g the p a t t e r n of e v o l u t i o n t a k i n g p l a c e among p o p u l a t i o n s of Peromyscus i n h a b i t i n g the i s l a n d s of B r i t i s h Columbia. A s t a n d a r d m o r p h o l o g i c a l approach, as v e i l as k a r y o t y p e and r e p r o d u c t i v e i s o l a t i o n a n a l y s e s , have shown t h a t a taxonomic r e v i s i o n of t h i s f a u n a l group i s d e s i r a b l e . I have proposed such a r e v i s i o n . A d i s c r i m i n a n t a n a l y s i s u t i l i z i n g m o r p h o l o g i c a l measurements r e v e a l s the e x i s t e n c e of two d i s t i n c t i v e phenotypes w i t h i n the i s l a n d s surveyed. B r e e d i n g s t u d i e s , i n v o l v i n g 78 p a i r s of i n s u l a r Peromyscus, i n d i c a t e t h a t r e p r o d u c t i v e i s o l a t i o n e x i s t s between the two morph groups. F u r t h e r m o r e , when g i v e n the c h o i c e the l a r g e and s m a l l morph groups p r e f e r the company of t h e i r own t y p e . E x t e n s i v e p h a l l i c v a r i a t i o n occurs among i s l a n d p o p u l a t i o n s but no sx i g g e s t i o n of taxonomic r e l a t i o n s h i p s are d i s c e r n i b l e . Karyotype a n a l y s i s r e v e a l s t h a t t h e r e are two d i s t i n c t k a r y o t y p i c p a t t e r n s . The k a r y o t y p e c o r r e l a t e s w i t h ,the two morphotype c l a s s i f i c a t i o n s . The l a r g e morph has a h i g h number of m e t a c e n t r i c chromosomes and the s m a l l morph has a low number. The h i g h m e t a c e n t r i c number k a r y o t y p e i s i d e n t i c a l t o t h a t possessed by the m o r p h o l o g i c a l l y s i m i l a r Peromyscus s i t k e h s i s known to i n h a b i t the i s l a n d s t o the n o r t h of t h e . s t u d y group. Karyotype v a r i a t i o n w i t h i n each of the t v o major d i v i s i o n s i s m i n i m a l . I have proposed t h a t the k a r y o t y p i c d i f f e r e n c e s between these two morphs i s s i g n i f i c a n t a t the s p e c i e s l e v e l . The l a r g e morph s h o u l d be c o n s i d e r e d as P_. s i t k e n s i s and the s m a l l phenotype s h o u l d remain as P. m a n i c u l a t u s . The degree and r a p i d i t y of e v o l u t i o n wi,thin these Peromyscus p o p u l a t i o n s r e q u i r e s a, b r o a d e n i n g i n the scope of som$ s u b s p e c i f i c t a x a . Change i n s u b s p e c i f i c nomenclature has been i n d i c a t e d . A d d i t i o n a l s t u d i e s of Peromyscus upon the a d j a c e n t mainland and Vancouver I s l a n d are r e q u i r e d b e f o r e m e a n i n g f u l r e l a t i o n s h i p s can be e x p r e s s e d between i n s u l a r and mainland grpups at the s u b s p e c i f i c l e v e l . TABLE OF CONTENTS T i t l e Page i A b s t r a c t i i Table of Contents i v L i s t of Tables i n Text v i L i s t o f F i g u r e s i n Text v i i . L i s t of Data T a b l e s , Appendix l a n d 2 v i i i L i s t of T a b l e s , D i s c r i m i n a n t F u n c t i o n Data, x, Appendix 3 L i s t of P l a t e s , K a r y o t y p i c Data, Appendix 4 x i I n t r o d u c t i o n 1 P o p u l a t i o n D e n s i t y , H a b i t a t S e l e c t i o n and Food P r e f e r e n c e s of I n s u l a r Peromyscus 11 M a t e r i a l s and Methods 13 R e s u l t s and D i s c u s s i o n 14 • The s o u t h e r n i s l a n d s 14 The n o r t h e r n i s l a n d s 18 W inter 25 Food p r e f e r e n c e s 25 Conclus i o n s 27 M o r p h o l o g i c a l and B e h a v i o r a l V a r i a t i o n i n I n s u l a r P o p u l a t i o n s of Peromyscus 32 M a t e r i a l s and Methods 33 C h a r a c t e r s measured 35 R e s u l t s and D i s c u s s i o n 36 A\" The c o n t i n e n t a l sample B: The s o u t h e r n i s l a n d s C: The n o r t h e r n i s l a n d s B r e e d i n g T e s t s and Comparative P o s t n a t a l Development of I n s u l a r and I n t e r - i s l a n d H y b r i d Peromyscus M a t e r i a l s and Methods R e s u l t s and D i s c u s s i o n The P h a l l u s and i t s B e a r i n g upon the C l a s s i f i c a t i o n of the I n s u l a r Peromyscus of B r i t i s h Columbia M a t e r i a l s and Methods . R e s u l t s and C o n c l u s i o n s De s c r i p t i o n of p h a l l i K a r y o t y p i c V a r i a t i o n i n I n s u l a r Peromyscus M a t e r i a l s and Methods Bone marrow method T i s s u e c u l t u r e method R e s u l t s and D i s c u s s i o n C o n c l u s i o n s : A S y s t e m a t i c Review of Some I n s u l a r Peromyscus Appendix 1 - Measurement d a t a f o r i n s u l a r Peromyscus Appendix 2 -q Body, t a i l and b o d y / t a i l r a t i o h i s t o g r a m d a t a Appendix 3 - D i s c r i m i n a n t a n a l y s i s d a t a Appendix 4 - K a r y o t y p e s of i n s u l a r Peromyscus Appendix 5 - Specimens examined Acknowledgements L i t e r a t u r e C i t e d LIST OF TABLES IN TEXT Trap success for beach and inland trap s i tes Keats Island Peromyscus survey, winter 1970. Body lengths for Peromyscus of the Georgia S t r a i t region. Average t a i l and foot measurements for the 1936 and 1968-1970 c o l l e c t i o n s . Degree and d i r e c t i o n of morphological change with time. Mean body measurements for Peromyscus of the coastal region of B r i t i s h Columbia. Male and female pa i r ing arrangement. Comparative c ran ia l measurements of Cox and Triangle Peromyscus and the i r hybrid young. Test crosses to determine ultimate breeding condit ions . Mate preferences. P h a l l i c specimens examined. P h a l l i c measurements for several species of Peromyscus. Divergence between i s land samples u t i l i z i n g the combined baculum and d i s t a l t rac t length measurements. Nomenclature for chromosome types. Co l l ec t ion and sample size data for the karyotype study. Karyotype charac ter i s t i c s for the Peromyscus of the B r i t i s h Columbia region. Proposed rev i s ion of the systematics of some i s land Peromyscus. V l l LIST. OF FIGURES IN TEXT 1 Map of B r i t i s h Columbia 8 2 Map of the Gordon, G o l e t a s , and S c o t t I s l a n d s of B r i t i s h Columbia. 9 3 Map of the G e o r g i a S t r a i t r e g i o n , B r i t i s h Columbia. 10 4 C o l l e c t i o n l o c a t i o n s f o r the c o n t i n e n t a l samples of Peromyscus m a n i c u l a t u s gambeli and P. m. rubidus..' 34 5 Changes i n body l e n g t h of P.m. g e o r g i e n s i s . 43 6 Changes i n t a i l l e n g t h of P.m. g e o r g i e n s i s . 43 7 Changes.in o c c i p i t o n a s a l l e n g t h of Peromyscus m. g e o r g i e n s i s . 44 8. R e l a t i o n s h i p s of i s l a n d Peromyscus ag determined by d i s c r i m i n a n t a n a l y s i s . \" 1 49 9 D i s p e r s a l r o u t e of a n c e s t r a l Peromyscus. 53 10 P o s t n a t a l growth i n weight f o r some i s l a n d and h y b r i d Peromyscus. 59 11 The p h a l l u s of Peromyscus m a n i c u l a t u s . 67 12 P h a l l i c c h a r a c t e r s . 68 13 Comparative g l a n s l e n g t h s . 75 14 Comparative b a c u l a l e n g t h s . 75 15 Somatic m e t a c e n t r i c chromosome numbers f o r some w e s t c o a s t p o p u l a t i o n s of Peromyscus. 86 1A C r a n i a l measurements f o r the Peromyscus i m a n i c u l a t u s gambeli sample. 101 2A S i g n i f i c a n c e of v a r i a t i o n between mean c r a n i a l measurements i n P. m, g a m b e l i . 102 3A C r a n i a l measurements f o r P. jn.- r u b i d u s sample. 103 4A S i g n i f i c a n c e of v a r i a n c e between mean c r a n i a l measurements i n P. m. r u b i d u s . . 104 5A C r a n i a l measurements , a l l c o l l e c t i o n s of P. m. g e o r g i e n s i s , 105 6 4 Body measurements f o r the 1968-11970 c o l l e c t i o n . 106 7A Body measurements f o r the pre-1952 c o l l e c t i o n . 107 8A C r a n i a l measurements f o r Pf-tn. g e o r g i e n s i s c o l l e c t e d i n 1936,1945, and 1968^ ! 108 9A C r a n i a l measurements f o r a l l c o l l e c t i o n s +,aken from the n o r t h e r n i n l a n d s . 109 10A Body measurements f o r a l l c o l l e c t i o n s . 110 11A C r a n i a l measurements f o r the 1936 and 1952 n o r t h e r n i s l a n d c o l l e c t i o n . I l l 12A C r a n i a l measurements f o r the 1968-1970 c o l l e c t i o n o n l y . 112 13A C r a n i a l measurements, maJes o n l y , a l l c o l l e c t i o n s . 113 14A C r a n i a l measurements, females o n l y , a l l c o l l e c t i o n s . 114 15A R e p r o d u c t i v e and developmental d a t a f o r i n t e r - i s l a n d h y b r i d Peromyscus. 115 16A R e p r o d u c t i v e a n d developmental d a t a f o r f i e l d c o n c e i v e d l i t t e r s . 115 17A I s l a n d Peromyscus p h a l l i c c h a r a c t e r i s t i c s 116 18A Mean p h a l l i c measurements and r a t i o s f o r i n s u l a r Peromyscus. 117 3.9A S i g n i f i c a n c e of v a r i a n c e between mean b a c u l a measurements. 118 2 P A S i g n i f i c a n c e of v a r i a n c e between t o t a l d i s t a l t r a c t measurements. 119 APPENDIX 2 Body and t a i l measurements and b o d y / t a i l r a t i o s , h i s t o g r a m s f o r each of the study i s l a n d s . FIGURE ISLAND 21A H i s t o g r a m d a t a f o r f.. Doyle 22A H u r s t 23A • • • • • B a l a c l a v a 24A N i g e i 25A V a n s i t t a r t 26A. ..Hope 27A Cox • . 28A Lanz 29A : T r i a n g l e 30A Savary 31A Texada 32A . Thormanby 33A Boven APPENDIX 3 D i s c r i m i n a n t a n a l y s i s d a t a . TABLE 21A D i s c r i m i n a n t f u n c t i o n c o e f f i c i e n t s . 22A The d e v i a t i o n s from the c o l l e c t i o n l o c a l i t y based on the d i s c r i m i n a n t a n a l y s i s . PLATE 1 Karyotype of Peromyscus m a n i c u l a t u s g e o r g i e n s i s , Boyen I s l a n d . 2 Karyotype of Peromyscus s i t k e n s i s i s o l a t u s , Cox I s l a n d . 3 Karyotype of Peromyscus s i t k e n s i s i s o l a t u s , N i g e i I s l a n d . 4 Karyotype of Peromyscus s i t k e n s i s d o y l e i , Doyle I s l a n d . 5 Karyotype of Peromyscus m a n i c u l a t u s g e o r g i e n s i s , Texada I s l a n d . 6 Karyotype of Peromyscus m a n i c u l a t u s g e o r g i e n s i s , Hope' I s l a n d . 7 Karyotype of Peromyscus s i t k e n s i s . saxamans, H u r s t I s l a n d . INTRODUCTION The s i g n i f i c a n c e of geographic i s o l a t i o n i n s p e c i a t i o n i s c o n t r o v e r s i a l and the s e a r c h f o r answers has l e d t o the r a i s i n g of many more q u e s t i o n s than have ever been answered. P. J . D a r l i n g t o n (1957) m a i n t a i n s t h a t i n s u l a r p o p u l a t i o n s are e v o l u t i o n a r y dead ends and are i n s i g n i f i c a n t i n t h e i r t o t a l c o n t r i b u t i o n t o the d i v e r s i t y of the w o r l d ' s s p e c i e s . Mayr (1966) has an opposing p o i n t of v i e w , h y p o t h e s i z i n g t h a t i s l a n d s are b r e e d i n g grounds f o r new s p e c i e s and t h a t these new s p e c i e s have g r e a t l y i n c r e a s e d the p r e s e n t day animal d i v e r s i t y . A n i m a l s have demonstrated the a b i l i t y t o d i s p e r s e a c r o s s most b a r r i e r s , but a s u c c e s s f u l c r o s s i n g does not n e c e s s a r i l y mean t h a t c o l o n i z a t i o n w i l l r e s u l t (MacArthur and W i l s o n , 1967). Indeed, t h e r e are numerous examples of easy a c c e s s of anim a l s t o i s o l a t e d areas y e t u n s u c c e s s f u l i n c o l o n i z a t i o n t h e r e . H y l a a r b o r e a i s found a c r o s s Europe b u t not i n England (Lack, 1969). R a t t u s e x u l a n s can be found on the P h i l i p p i n e s , C e l e b e s , New Zeala n d , and New Guinea but not on the mainland of A u s t r a l i a ( J . M. T a y l o r , p e r s o n a l communication). I r e l a n d has o n l y t h r e e - f i f t h s of the b i r d fauna found i n England. I n Fernando Poo 30 p e r c e n t of the b i r d f a u n a i s endemic whereas i n Z a n z i b a r o n l y 3 p e r c e n t of the a v i f a u n a i s endemic, y e t bo t h of these i s l a n d s are the same d i s t a n c e from the mainland (Lack, 1969). I t i s obvious t h a t more th a n the a b i l i t y t o c r o s s b a r r i e r s determines the d i s p e r s a l and e v o l u t i o n of many a n i m a l s . W i t h i n s m a l l f o u n d i n g c o l o n i e s g e n e t i c d r i f t can b r i n g abput major changes i n s h o r t p e r i o d s of t i m e . One c l a s s i c case i s t h a t of the Darwin F i n c h e s on the Galapagos I s l a n d s (Lack, 1947). The d i v e r s i f i c a t i o n of one hundred s p e c i e s of b i r d s found upon the Galapagos I s l a n d s c o n t r a s t s w i t h the l a c k of s p e c i e s d i v e r s i t y i n the a v i a n f a u n a . o f the C a r i b b e a n I s l a n d s . Each i s l a n d s i t u a t i o n conveys the i m p r e s s i o n t h a t i t i s a l a r g e s c a l e experiment i n n a t u r e . The s t u d y of the Peromyscus i n h a b i t i n g the i s l a n d s i n the G u l f of C a l i f o r n i a ( L a w l o r , 1971) has o b t a i n e d a degree of c o m p l e x i t y s i n c e 18 r e c o g n i z e d s p e c i e s i n h a b i t the G u l f r e g i o n . My study d i f f e r s from t h a t of L a v l o r ' s i n t h a t the Peromyscus p o p u l a t i o n s i n v e s t i g a t e d have been c o n s i d e r e d a l l of the s p e c i e s m a n i c u l a t u s (McCabe and Cowan, 1945; G u i g u e t , 1952). The i s l a n d s of B r i t i s h Columbia are one of the few r e m a i n i n g N o r t h American l o c a t i o n s where n a t u r a l p o p u l a t i o n s of Peromyscus can be found e x i s t i n g i n a s t a t e not u n d u l y u p s e t or changed by human i n t e r v e n t i o n . The, San Juan I s l a n d s a t the entrance t o Puget Sound have l o n g been c o l o n i z e d by man, and most of the l a r g e r i s l a n d s a l o n g the c o a s t have been l o g g e d . There a r e , h o w e v e r m a n y s m a l l e r i s l a n d s i n the n o r t h e r n r e g i o n which s t i l l e x i s t i n a p r i s t i n e c o n d i t i o n . Numerous s u b s p e c i e s of the s p e c i e s P. m a n i c u l a t u s have been d e s c r i b e d from the i s l a n d s of the c o a s t of B r i t i s h Columbia (Cowan, 1935; H a l l , 1938; McCabe and Cowan, 1945; Cowan and Gu i g u e t , 1965). Such an a r e a i s i d e a l f o r an i n v e s t i g a t i o n i n t o the s y s t e m a t i c s of c l o s e l y r e l a t e d a l l o p a t r i c p o p u l a t i o n s . McCabe and Cowan (1945) e x p r e s s e d concern f o r the need of g e n e t i c i n v e s t i g a t i o n of t h i s complex group when t h e y s t a t e d , \" I t i s almost u n t h i n k a b l e t h a t an a n c i e n t l y d e r i v e d s t r a i n of complex and d i s t a n t o r i g i n rPeromyscus maniculatus1 c o u l d have m i g r a t e d from somewhere beyond the i c e c a p p e d a r e a and c o n t i n u e d to get i t s e l f marooned on so s m a l l and i n a c c e s s i b l e , a range w i t h o u t l e a v i n g a g e n e t i c t r a i l over the course of i t s m i g r a t i o n . \" Dice (1948) p o i n t e d out t h a t 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 i n the body measurements of mice t a k e n from l o c a t i o n s 10 m i l e s a p a r t on the same i s l a n d . I n t h i s s tudy Dice r e c o r d e d v a r i a t i o n s i n ear l e n g t h of about 0.7 mm., i n t a i l i • l e n g t h of 6.3 mm., and i n body l e n g t h of 2.5 mm.; these d i f f e r e n c e s are g r e a t e r t h a n those e x i s t i n g between some e s t a b l i s h e d c o n t i n e n t a l s u b s p e c i e s . B e r r y (1964), i n h i s a n a l y s i s pf the s m a l l mammal fauna of B r i t a i n , p o i n t s out t h a t the m a j o r i t y of r e c o r d e d s u b s p e c i e s of Apodemus, M i c r o t u s , and C l e t h r i o n o m y s are i s l a n d p o p u l a t i o n s t h a t have been d e s i g n a t e d as new forms. Yet the work of Delany and B i s h o p ( i 9 6 0 ) notes t h a t the o n l y r e a l d i f f e r e n c e i n two s u b s p e c i e s of C l e t h r i o n o m y s i s a s m a l l and v a r i a b l e t o o t h c h a r a c t e r i s t i c . H a l l , i n h i s 1938 st u d y of the Peromyscus of the G e o r g i a i s l a n d s , d eveloped a degree of i s o l a t i o n -' t a i l l e n g t h f o r m u l a w h i c h demonstrates c o n s i s t e n t geographic v a r i a t i o n i n the body t o t a i l l e n g t h r a t i o . However, H a l l r e g a r d e d the d i f f e r e n c e as too i n s i g n i f i c a n t to deserve s u b s p e c i f i c r e c o g n i t i o n . I t seems t h a t the s i g n i f i c a n c e of the v a r i a n c e i n i n t e r - i s l a n d s m a l l mammal p o p u l a t i o n s i s a mat t e r l e f t t o the whims and p e r s o n a l p r e f e r e n c e s of the i n v e s t i g a t o r . One c o u l d perhaps abandon the c l a s s i c a l concept of nomenclature and a c c e p t the s u g g e s t i o n put f o r t h by W i l s o n and Brown (1953). Under t h e i r scheme a l l i s l a n d p o p u l a t i o n s would be known by geographic v e r n a c u l a r and not by a b i o l o g i c a l t r i n o m i a l . Such an arrangement would s i m p l i f y the problem of nomenclature but would i m p l y no p h y l o g e n e t i c p a t t e r n . R e t u r n t o such a p r e - L i n n e a n system would, i n my o p i n i o n , serve no sound b i o l o g i c a l purpose. What i s needed i s f o r tax o n o m i s t s t o d e r i v e some u n i v e r s a l formulae d e a l i n g w i t h a l l o p a t r i c p o p u l a t i o n s and t o adhere t o them d e s p i t e p e r s o n a l dogmas. The o b j e c t i v e of t h i s s tudy i s to r e - i n v e s t i g a t e the s y s t e m a t i c s of sOme i s l a n d Peromyscus by u s i n g s t a n d a r d c r a n i a l and body measurements, a e u r y t o p i c approach, as w e l l as by s t u d y i n g c r y p t i c c h a r a c t e r s not p r e v i o u s l y c o n s i d e r e d i n the taxonomic e v a l u a t i o n of t h i s group. The s i g n i f i c a n c e of the m o r p h o l o g i c a l v a r i a t i o n e x i s t i n g w i t h i n and between these i s l a n d p o p u l a t i o n s i s a c h i e f f o c a l p o i n t . The d i r e c t i o n of r a d i a t i o n , and where p o s s i b l e , the c l i n e s i n r e l a t i o n s h i p s , e x i s t i n g w i t h i n t h i s group are a s c e r t a i n e d by b o t h m o r p h o l o g i c a l and k a r y o t y p i c c h a r a c t e r s . D e t e r m i n a t i o n of k a r y o t y p i c v a r i a t i o n i s of prime i n t e r e s t f o r I b e l i e v e t h i s f e a t u r e h o l d s g r e a t p o t e n t i a l i n d e c i p h e r i n g p r o b a b l e e v o l u t i o n a r y pathways of Peromyscus i n i s l a n d p o p u l a t i o n s . The c o m p l e x i t y of k a r y o t y p e s i n the genus Peromyscus i s w e l l documented i n the l i t e r a t u r e but the papers of A r a k a k i and Sparkes (1965, a, b ) , Hsu and A r r i g h i (1966, 1968), Ohno e t a l (1966), and Si n g h and M c M i l l a n (1966) e s t a b l i s h tha,t many p o p u l a t i o n s of Peromyscus are k a r y o t y p i c a l l y u n i q u e . K a r y o t y p i c a n a l y s e s of c o n t i n e n t a l p o p u l a t i o n s are c o m p l i c a t e d by the u n c e r t a i n t y of s p e c i e s b a r r i e r s , w h i l e the degree of sympatry, h y b r i d i z a t i o n , and i n t e r - p o p u l a t i o n r e l a t i o n s h i p s are in, most cases unknown. A t the p r e s e n t time chromosome polymorphism w i t h i n any one ta x o n c r e a t e s a s t u m b l i n g b l o c k f o r the t a x o n o m i s t . The k a r y o t y p i c v a r i a t i o n i n Peromyscus t r u e i (Hsu and A r r i g h i , 1968) i s one of the few examples : where k a r y o l o g i c a l d a t a s u b s t a n t i a t e the c o n c l u s i o n s of an i n v e s t i g a t i o n based on gross morphology. H o f f m e i s t e r ( l 9 5 l ) c o n c l u d e d i n h i s study t h a t P. t r u e i i s composed of two , g e n e t i c l i n e s . T h i s has been s u b s e q u e n t l y c o n f i r m e d by ka r y o t y p e p a t t e r n s . I f a d i v i s i o n i n the k a r y o t y p e s of i s l a n d mice can be found t h e n t h i s c o u l d r e p r e s e n t a b r e a k t h r o u g h i n the stu d y of d i s p e r s a l pathways and taxpnomic r e l a t i o n s h i p s among these i n s u l a r r o d e n t s . The i s l a n d environment p r o v i d e s p o p u l a t i o n s t h a t are u n q u e s t i o n a b l y a l l o p a t r i c , w i t h chances of h y b r i d i z a t i o n and i n t e r i s l a n d c r o s s e s b e i n g m i n i m a l . The d i s t r i b u t i o n of Peromyscus i s not c o n t i n u o u s a l o n g these beaches; i n s t e a d , , t h e r e are d i s c r e t e p o p u l a t i o n s w h i c h i n e f f e c t are d u p l i c a t i n g the a l l o p a t r i c s i t u a t i o n found among c o n t i n e n t a l s p e c i e s ; T h i s l a t t e r p o i n t i n c r e a s e s the chance of f i n d i n g chromosome polymorphism, i f i t e x i s t s , and s h o u l d p r o v i d e an e x c e l l e n t check upon the i n h e r e n t s t a b i l i t y of the chromosome compliment. I n a n o n - R o b e r t s o n i a n system any k a r y o t y p i c change has to come about by i n v e r s i o n , d e l e t i o n , or a d d i t i o n . T h i s tends t o c o m p l i c a t e and r e t a r d recombina-t i o n s more th a n i n a, R o b e r t s o n i a n system where t r i s o m y can and does e x i s t to c o u n t e r a c t most d i s c r e p a n c i e s or i r r e g u l a r i t i e s i n the genome. A l t h o u g h any g r o s s d i f f e r e n c e e x i s t i n g between k a r y o t y p e s would tend to reduce r e c o m b i n a t i o n and the l e v e l of f e c u n d i t y may be l o w e r e d , s u c c e s s f u l c r o s s e s can take p l a c e . I f t h e r e i s any s p e c i a l a d a p t a t i o n t o a new c o m b i n a t i o n and d i f f e r e n t k a r y o t y p e , then s t a s i p a t r y , the. e v o l u t i o n of a new s p e c i e s , through k a r y o t y p i c change (Whi;te, 1967), can become a r e a l i t y . My s t u d y i n v o l v e s two g e o g r a p h i c a l l y i s o l a t e d i n s u l a r groups t o t a l l i n g 13 i s l a n d s and i n v o l v i n g 30 d i f f e r e n t l o c a t i o n s . The i s l a n d s v a r y i n s i z e from those h a v i n g a few y a r d s of s u i t a b l e beach ( i . e . D o y l e ) , to those p o s s e s s i n g many m i l e s of good h a b i t a t ( i . e . Texada). The n o r t h e r n group, of 9 i s l a n d s and 24 study l o c a t i o n s , has a wide spectrum of Peromyscus morphotypes and i s r e p r e s e n t e d i n the l i t e r a t u r e by s i x s u b s p e c i e s and one as y e t un-named r a c e . The s o u t h e r n i s l a n d group has but one morphotype, Peromyscus m a n i c u l a t u s g e o r g i e n s i s H a l l . The f o u r s o u t h e r n i s l a n d s have been t r a p p e d i n such a way as to have a r e p r e s e n t a t i v e sample from most of the obvious h a b i t a t t y p e s , such as the beach, f o r e s t and g r a s s l a n d s , i n o r d e r %o t e s t f o r i n t e r - p o p u l a t i o n v a r i a t i o n and the p o s s i b i l i t y of h a b i t a t - s p e c i f i c k a r y o t y p e s , i f such e x i s t . 138 ' 126 1 ' 121 12? I' 1 . ' ! — BRITISH COLUMBIA F i g . 2 The Gordon, G o l e t a s , and S c o t t I s l a n d s of B r i t i s h Columbia. F i g . 3 The Georgia S t r a i t region, B r i t i s h Columbia. !—1 o POPULATION DENSITY, HABITAT SELECTION AND FOOD PREFERENCES OF INSULAR PEROMYSCUS.'. . M a i n l a n d p o p u l a t i o n s of Peromyscus m a n i c u l a t u s have been the f o c u s of i n t e n s i v e i n v e s t i g a t i o n f o r many decades. E x c e l l e n t r e f e r e n c e s p e r t a i n i n g t o p o p u l a t i o n d e n s i t i e s , h a b i t a t s e l e c t i o n and f o o d p r e f e r e n c e s of c o n t i n e n t a l p o p u l a t i o n s are too numerous to l i s t , however the works of B l a i r (1942, 1950, 1951), Dice (1932, 1939, 1940a,b, 1941a), H a l l (1938), and H a l l and K e l s o n (1959). are. of major. . importance i n b r i n g i n g about an u n d e r s t a n d i n g of the c o m p l e x i t y of t h i s genus on the mainland. I s l a n d p o p u l a t i o n s have y e t t o be i n v e s t i g a t e d to a comparable degree. Taxonomic i n v e s t i g a t i o n s of the Peromyscus fauna have been made on many, b u t by no means a l l , of the i s l a n d s found a l o n g the c o a s t of N o r t h America. The most n o t a b l e of the i s l a n d s t u d i e s are those of Osgood (1901, 1909), B u r t (1932), McCabe and Cowan (1945), Dice (1949), and F o s t e r (1965). I t i s not apparent from these s t u d i e s whether the tremendous m o r p h o l o g i c a l v a r i a t i o n e x i s t i n g between these i s l a n d p o p u l a t i o n s i s a l s o accompanied by s i m i l a r v a r i a t i o n i n n i c h e c r i t e r i a . D u r i n g the summers of 1968, 1969, and 1970 I t r a p p e d upon 14 i s l a n d s , a l o n g the c o a s t of B r i t i s h Columbia. Bowen, Thormanby, Texada and Savary (see f i g s . 1, 2, 3) are i n h a b i t e d by Peromyscus m a n i c u l a t u s g e o r g i e n s i s a s u b s p e c i e s which has been c h a r a c t e r i z e d as h a v i n g l i t t l e m o r p h o l o g i c a l v a r i a t i o n ( H a l l , 1938). The monotypic phenotype and the l a r g e d i s t a n c e between the i s l a n d p o p u l a t i o n s c o n t r a s t s w i t h the n o r t h e r n i s l a n d sample ( f i g . 2) where g r e a t m o r p h o l o g i c a l v a r i a t i o n o c c u r s between g e o g r a p h i c a l l y c l o s e i s l a n d p o p u l a t i o n s . The s o u t h e r n i s l a n d group of Bowen, Thormanby, Texada, and Savary, has a m i l d c l i m a t e w i t h ah average r a i n f a l l of l e s s t h a n 60 i n c h e s per y e a r . Ground c o v e r , a l t h o u g h f a i r l y dense i n c e r t a i n a r e a s , does not h i n d e r one's passage and t r a p l i n e s can, be l a i d i n most areas w i t h o u t undue d i f f i c u l t y . The second group of i s l a n d s i n v e s t i g a t e d i s c l u s t e r e d around the n o r t h e r n t i p of Vancouver I s l a n d . These are D o y l e , H u r s t , B a l a c l a v a , N i g e i , V a n s i t t a r t and Hope I s l a n d s . A l t h o u g h t h e y are g e o g r a p h i c a l l y c l o s e t o g e t h e r , t h e y have a number of m o r p h o l o g i c a l l y d i s t i n c t p o p u l a t i o n s of Peromyscus. I n t h i s a r e a r a i n f a l l can be as h i g h as 160 i n c h e s a y e a r and the v e g e t a t i o n t a k e s on a temperate r a i n f o r e s t appearance. The undergrowth i s so l u x u r i a n t t h a t passage i s d i f f i c u l t and the l a y i n g of t r a p s anywhere ot h e r than the beach i s a v e r y time consuming and hazardous u n d e r t a k i n g . Consequently, on these and o t h e r n o r t h e r n i s l a n d s I have t r a p p e d h e a v i l y upon beach areas and o n l y a l i m i t e d f a s h i o n i n l a n d . The l a s t group of i s l a n d s s t u d i e d i s composed of the S c o t t I s l a n d s , l o c a t e d 5 t o 20 m i l e s t o the west of Cape S c o t t , a t the n o r t h e r n t i p of Vancouver I s l a n d . These i s l a n d s are well-known f o r t h e i r adverse weather c o n d i t i o n s . I n October, 1912, f o r example, the r o o f of the l i g h t h o u s e on T r i a n g l e I s l a n d , the westernmost of the S c o t t I s l a n d s , was blown o f f , two sheds d i s a p p e a r e d , and a l l smoke s t a c k s were blown down. Winds of up t o 105 m.p.h. have been r e p o r t e d f o r t h i s i s l a n d . ( C a r l e t a l , 1950 pp. 21-63). A l l d e s c r i p t i o n s of w i n t e r h a b i t a t s f o r i s l a n d Peromyscus are d e r i v e d s o l e l y from the s o u t h e r n i s l a n d s , f o r o n l y here d i d the weather c o n d i t i o n s p e r m i t a c c e s s and t r a p p i n g o p p o r t u n i t y a t t h i s season of the y e a r . MATERIALS AND METHODS I found the g r i d t r a p p i n g p r o cedures f o r the census of s m a l l a n imal p o p u l a t i o n s ( D i c e , 1941b; B o l e , 1939) i m p o s s i b l e to implement i n the m a j o r i t y of i s l a n d s i t u a t i o n s . The v e g e t a t i o n and g e o l o g i c a l c o n t o u r s were too f o r m i d a b l e f o r t h i s type of proce d u r e . Consequently, I p l a c e d a l l t r a p s a l o n g areas of u n i f o r m t e r r a i n and ground c o v e r , and a t a p p r o x i m a t e l y f i v e y a r d i n t e r v a l s . The t r a p s were b a i t e d w i t h peanut b u t t e r and oatmeal. Towards the end of the t r a p p i n g p e r i o d I used a b a i t found t o be j u s t as e f f e c t i v e , y e t e a s i e r t o a p p l y . T h i s b a i t c o n s i s t e d of peanut o i l w i t h d i s s o l v e d peanut b u t t e r (50:1 mix) a p p l i e d by a gun type o i l can. The t r a p l i n e s c o n s i s t e d of Sherman 8\" l i v e t r a p s and Museum S p e c i a l snap t r a p s . Stomachs from the snap t r a p p e d specimens were removed and p r e s e r v e d i n f o r m a l i n f o r l a t e r a n a l y s i s of t h e i r c o n t e n t . I have c o n s i d e r e d d e n s i t y t o be d i r e c t l y r e l a t e d t o the number of i n d i v i d u a l s caught a t any one l o c a t i o n d u r i n g the f i r s t t h r e e , or fewer, t r a p n i g h t s . By u s i n g the r e s u l t s of o n l y the f i r s t t h r e e t r a p n i g h t s ( t a b l e l ) the e f f e c t of the d e p l e t i n g p o p u l a t i o n numbers upon the p e r c e n t t r a p r e t u r n i s m i n i m i z e d y e t the chances of o b t a i n i n g an adequate sample i s maximized. I found t h a t a l i g h t r a i n brought about the maximum t r a p c a p t u r e s and a c l e a r sky d u r i n g the n i g h t produced almost no r e t u r n s . F o r t u n a t e l y , i n the n o r t h e r n i s l a n d group evening r a i n s are t o be expected thus g u a r a n t e e i n g comparable weather c o n d i t i o n s f o r the d u r a t i o n of the t r a p p i n g p e r i o d . A l l mice of the s o u t h e r n i s l a n d group were t r a p p e d d u r i n g p e r i o d s of good weather and u s u a l l y w i t h o u t n i g h t r a i n s . A l t h o u g h c o n s t a n t weather c o n d i t i o n s o c c u r r e d f o r a l l samples w i t h i n each i s l a n d group the weather v a r i a t i o n s between groups were p r o b a b l y not conducive t o the procurement of maximum t r a p r e t u r n s i n each case. RESULTS AND DISCUSSION The Southern I s l a n d s : Bowen, Thormanby, Texada, and Savary. On Bowen I s l a n d , Peromyscus were found s c a v e n g i n g a l o n g the i n t e r t i d a l zone. Peromyscus o c c u r r e d r e g u l a r l y a l o n g the e n t i r e , e x t e n s i v e beach a r e a . T h i s s i t u a t i o n c o n t r a s t s w i t h the a l l o p a t r i c n a t u r e of beach p o p u l a t i o n s i n the n o r t h e r n i s l a n d groups. The h i g h e s t d e n s i t y of Peromyscus oc c u r s a l o n g the l i t t o r a l zone of those g e n t l y s l o p i n g beaches h a v i n g a t r a n s i t i o n zone of dry underbrush between the beach and the c l i m a x f o r e s t . The i n t e r t i d a l zone i s r i c h i n p o t e n t i a l i n v e r t e b r a t e f o o d sources and I was soon a b l e to r e c o g n i z e p o t e n t i a l l y BEACH INLAND ISLAND # TRAP # ANIMALS NIGHTS CAUGHT % TRAP SUCCESS # TRAP # ANIMALS NIGHTS CAUGHT % TRAP SUCCESS DOYLE 780 8 1.0 120 0 0 HURST 74 5 6.8 N.T. BALACLAVA 320 9 2.8 N.T. NIGEI 320 12 3.7 90 15 16.5 VANSITTART 160 12 • 7.5 60 0 0 HOPE 520 13 2.5 60 0 0 COX 84 17 20.2 N.T. LANZ 136 32 23.5 120 0 0 BERESFORD N.T. 40 0 0 TRIANGLE 80 25 31.3 40 5 12.5 BOWEN 120 11 9.1 60 0 0 THORMANBY 180 5 2.75 270 12 4.4 TEXADA 240 26 10.8 450 41 9.1 SAVARY 20 0 0 160 . 18 11.2 (N.T. a r e a not t r apped) Table 1 Trap success f o r beach and i n l a n d t r a p s i t e s . good t r a p s i t e s by the amount and f r e s h n e s s of the beach d e b r i s . Brand and Rykman (1968), i n t h e i r study of Peromyscus g u a r d i a of the I s l a Lorenzo Sur M e x i c o , had noted a s i m i l a r h a b i t a t p r e f e r e n c e and have suggested t h a t P. g u a r d i a was e x i s t i n g upon the beach d e b r i s . I have s u b s e q u e n t l y found by stomach c o n t e n t a n a l y s i s , t h a t the Peromyscus i n h a b i t i n g the i s l a n d s of B r i t i s h Columbia are indeed s u b s i s t i n g upon i n t e r t i d a l i n v e r t e b r a t e s . C l i f f a r e a s , v e t underbrush zones, open g r a s s pr l o g g e d areas on Bowen I s l a n d y i e l d e d no Peromyscus, Thormanby I s l a n d has v e r y few beaches comparable t o the type on Bowen I s l a n d t h a t h a r b o r s Peromyscus. The most p r o m i s i n g r e g i o n on Thormanby has l o n g s i n c e been t a k e n over by s u b d i v i d e r s , and homes occupy what I b e l i e v e was once the p r e f e r r e d Peromyscus h a b i t a t . S i n c e the r e m a i n i n g c o a s t l i n e of Thormanby. i s p r e c i p i t o u s i t was not s u r p r i s i n g t o f i n d t h a t Peromyscus d e n s i t i e s were e x t r e m e l y low. The 2.75 p e r c e n t t r a p s u ccess a l o n g the i n t e r t i d a l zone, and the 4.4 p e r c e n t t r a p success from the i s l a n d i n t e r i o r are comparable t o the s o r t of r e t u r n s t h a t I would expect from the s i m i l a r h a b i t a t type on the o t h e r i s l a n d s , and I t h i n k i t emphasizes the importance of the abundant f o o d s u p p l i e s found on the beaches. T e x a d a . I s l a n d , the l a r g e s t i s l a n d t r a p p e d i n t h i s s t u d y , has a d e s o l a t e c o a s t l i n e w i t h many s e c l u d e d bays. The 10.8 p e r c e n t t r a p success compares f a v o r a b l y t o the 9.1 p e r c e n t r e c o r d e d f o r the Bowen i n t e r t i d a l y i e l d . The Peromyscus d e n s i t y i n the i s l a n d i n t e r i o r , 9.1 p e r c e n t , was f a r g r e a t e r t h a n t h a t r e c o r d e d f o r e i t h e r c e n t r a l Bowen or Thormanhy I s l a n d s . I n t h r e e n i g h t s of t r a p p i n g i n a logged a r e a f o u r m i l e s west of Vananda, Peromyscus o c c u r r e d a t a d e n s i t y of abqut 10 p e r c e n t a l o n g the edge of the r o a d and a t a l e s s e r e x t e n t , about 8 p e r c e n t , i n among the s l a s h l e f t by the l o g g i n g crews. The d i f f e r e n c e , I b e l i e v e , i s a t t r i b u t a b l e t o the g r e a t e r f l o r a l d i v e r s i t y upon Texada, and t h i s d i v e r s i t y i s a t t r a c t i n g an abundance of i n s e c t s t h a t c o u l d p o s s i b l y be u t i l i z e d as a f o o d s o u r c e . Thormanby I s l a n d i s a r o c k y , s p a r s e l y v e g e t a t e d i s l a n d and Bowen, where i t i s not i n h a b i t e d by p e o p l e , seems to be too wet f o r Peromyscus c o l o n i z a t i o n . A l o n g the Texada coast,, as on the two p r e v i o u s l y s t u d i e d i s l a n d s , c l i m a x f o r e s t and r o c k y c l i f f s a c t as b a r r i e r s between Peromyscus p o p u l a t i o n s . Savary I s l a n d i s the most unusual of the s o u t h e r n i s l a n d s f o r i t i s b o r d e r e d by a w i d e, w h i t e sand beach on the e a s t c o a s t arid a s h eer, sandy c l i f f on the west. The i n t e r v e n i n g a r e a , o n l y a few hundred f e e t i n w i d t h , has been logged and a dense growth of Red A l d e r , A l n u s r u b r a Bong, S a l l a l , G a u l t h e r i a s h a l l o n P u r s h , and f e r n s p e c i e s has r e p l a c e d the o l d f o r e s t . P o t e n t i a l s u b d i v i d e r s have made numerous pathways through t h i s a r e a and i n so d o i n g t h e y have c r e a t e d a s t a t e of e c o l o g i c a l t u r m o i l . The d e n s i t y of the Peromyscus p o p u l a t i o n was. h i g h e r here t h a n on any of the p r e v i o u s l y s t u d i e d i s l a n d s . I f t h i s h i g h e r d e n s i t y was the r e s u l t of c r o w d i n g due to d i s p l a c e m e n t of mice from o t h e r h a b i t a t s t h e n t h i s would perhaps e x p l a i n the e x i s t e n c e of two k a r y o t y p e s i n t h i s a p p a r e n t l y p a n m i c t i c group (Thomas, 1970). No mice were t r a p p e d i n the c l i m a x f o r e s t , g r a s s l a n d or marsh a r e a s . The N o r t h e r n I s l a n d s : D o y l e , H u r s t , B a l a c l a v a , N i g e i , V a n s i t t a r t , Hope, Cox, Lanz, B e r e s f o r d and T r i a n g l e . Development on these i s l a n d s has been l i m i t e d and a t the p r e s e n t time o n l y two permanent i n s t a l l a t i o n s e x i s t , a l i g h t h o u s e on B a l a c l a v a and a Department of T r a n s p o r t r a d i o s t a t i o n on Hope. Two I n d i a n v i l l a g e s , now i n d e c a y i n g r u i n s , a l o n g w i t h a few s i n g l e i s o l a t e d d w e l l i n g s , i n d i c a t e t h a t these i s l a n d s were once the home of many I n d i a n f a m i l i e s . S i n c e these people were not a g r i c u l t u r a l l y o r i e n t e d t h e y made r e l a t i v e l y l i t t l e m o d i f i c a t i o n t o t h e i r environment. Consequently, the s m a l l mammal fauna has p r o b a b l y remained l a r g e l y u n a f f e c t e d by these e a r l y human i n h a b i t a n t s . Doyle I s l a n d Doyle I s l a n d , l o c a t e d t h r e e m i l e s n o r t h of P o r t Hardy, i s a t w i n peaked mound of r o c k w i t h a maximum e l e v a t i o n of l e s s t h a n 400 f e e t . There are no sandy beaches and the b e s t boat l a n d i n g approach i s the n o r t h or south slope of a saddle of l a n d between the two r o c k peaks. T h i s saddle i s d e n s e l y g r a s s e d and p r o v i d e s easy access t o b o t h s i d e s of the i s l a n d . The r e s t of the i s l a n d i s s p a r s e l y f o r e s t e d , w i t h s a l l a l as ground cover i n the more open a r e a s . The few Peromyscus c o l l e c t e d on t h i s i s l a n d (n = 8 f o r 780 t r a p n i g h t s ) were found around the r o o t s of t r e e s under the s a l l a l on the n o r t h s i d e of the g r a s s y saddle a r e a . Traps p l a c e d upon the r o c k y c l i f f f a c e s and around the s t e p i s l a n d c o a s t l i n e y i e l d e d no Peromyscus. H u r s t and B a l a c l a v a These are f a i r l y s m a l l i s l a n d s , d e n s e l y f o r e s t e d , and w i t h many stony beaches. On b o t h of these i s l a n d s the q u i e t , s e c l u d e d bays d i d not produce any mice. The one g r a s s y a r e a , an abandoned I n d i a n v i l l a g e on B a l a c l a v a , y i e l d e d no mice even though e v i d e n c e , i n the form of numerous runs made by M i c r o t u s , c o u l d be found. Peromyscus were t r a p p e d o n l y upon p e r t a i n beach a r e a s . I t was upon these i s l a n d s t h a t the p r e f e r r e d h a b i t a t f o r Peromyscus was more c l e a r l y d e f i n e d . The p r o d u c t i v e a r e a s were i n many r e s p e c t s s i m i l a r t o the g e n t l e s l o p i n g beaches of Bowen I s l a n d . These beaches always had a c o n s t a n t l y renewed s u p p l y of sea weed d e p o s i t e d a l o n g the h i g h water mark, and y e t were not s u b j e c t t o heavy sea spray . Peromyscus seem t o a v o i d the c o n s t a n t l y damp areas b o t h on the beaches and under the s a l l a l covered s l o p e s . T r a p p i n g r e c o r d s i n d i c a t e a p r e f e r e n c e f o r w e l l d r a i n e d , or s m a l l r o c k beaches. N i g e i I s l a n d The west end of N i g e i I s l a n d gave s i m i l a r t r a p p i n g d a t a t o t h a t of B a l a c l a v a and H u r s t I s l a n d s . Here a g a i n the w e l l d r a i n e d beaches w i t h f r e s h sea weed d e p o s i t e d upon g e n t l e s l o p e s t h a t l e a d up i n t o the f o r e s t e d a r e a produced the g r e a t e s t number of Peromyscus. Lo g g i n g o p e r a t i o n s have c l e a r e d much of the e a s t e r n end of N i g e i I s l a n d . V a c c i n i a , Rubus and the ever p r e s e n t s a l l a l have grown up c r e a t i n g a dense but low ground cover over the l o g g e d s l o p e s . A l o n g the edge of the l o g g i n g r o a d Peromyscus o c c u r r e d a t h i g h d e n s i t y l e v e l s . S i x t e e n and a h a l f p e r c e n t of the t r a p s s e t a l o n g the s i d e of the t r a i l c a p t u r e d Peromyscus. T h i s i s more th a n a f o u r f o l d i n c r e a s e over the beach h a b i t a t t r a p s u ccess r a t e . P l a n t d i v e r s i t y and a s s o c i a t e d i n v e r t e b r a t e f o o d sources are b e l i e v e d t o be r e s p o n s i b l e f o r the h i g h d e n s i t y . V a n s i t t a r t I s l a n d ... T h i s i s a, very, s m a l l i s l a n d l o c a t e d midway between N i g e i and Hope- I s l a n d s . A l l t w e l v e mice c a p t u r e d d u r i n g the 240 t r a p n i g h t s were caught, i n a v e r y d i s t i n c t i v e r e g i o n . On the southwest c o r n e r of the i s l a n d t h e r e i s one sandy, w e l l d r a i n e d s l o p i n g beach b o r d e r e d by s t eep r o c k y c l i f f s . The mice were found to i n h a b i t the f l a t a r e a , and a v o i d e d the dense f o r e s t and r o c k y c l i f f r e g i o n . S i n c e the 160 t r a p n i g h t s ( t a b l e l ) upon the beach i n c l u d e d 40 t r a p n i g h t s of s ampling the r o c k y c l i f f zone, the 7.5 p e r c e n t t r a p success i s not a f a i r i n d i c a t i o n of the p r e f e r e d h a b i t a t d e n s i t y . A l l Peromyscus on V a n s i t t a r t were h e a v i l y i n f e s t e d w i t h e c t o p a r a s i t e s . T h i s was the o n l y i s l a n d l o c a t i o n where f l e a s , t i c k s , and ear m i t e s were so abundant on each mouse t h a t t h e y must have, r e p r e s e n t e d a l a r g e p h y s i c a l \" l o a d \" upon t h e i r h o s t s . The o t h e r i s l a n d s sampled i n t h i s s t u d y produced r e m a r k a b l y p a r a s i t e - f r e e Peromyscus. Hope I s l a n d T h i s i s the westernmost i s l a n d of the Gordon group. I t i s an I n d i a n r e s e r v e and, a l t h o u g h i t i s now d e s e r t e d , i t was once the home of s e v e r a l I n d i a n f a m i l i e s . The l a n d t h a t was c l e a r e d f o r the I n d i a n v i l l a g e has become a haven f o r M i c r o t u s townsendi but not f o r Peromyscus. The g r a s s l a n d , a d j a c e n t b r u s h and f o r e s t i n t e r i o r y i e l d e d no Peromyscus. T r a p p i n g success f o r a l l beaches on the e a s t and s o u t h e r n c o a s t produced v e r y poor r e s u l t s . B u l l Harbor, my camp s i t e on Hope I s l a n d , was h e a v i l y t r a p p e d d u r i n g the summer of 1969. Even:though a l l c r i t e r i a p r e v i o u s l y determined as b e i n g n e c e s s a r y f o r Peromyscus c o l o n i z a t i o n seemed p r e s e n t , w i t h the p o s s i b l e e x c e p t i o n of a d a i l y i n f l u x of f r e s h seaweed, few p l a c e s around t h i s n a t u r a l h a r b o r produced Peromyscus. I b e l i e v e t h a t o i l p o l l u t i o n from the f i s h i n g b o a t s and f i s h camp has r e s u l t e d i n the c o n t a m i n a t i o n and u l t i m a t e e x t e r m i n a -t i o n of most i n t e r t i d a l l i f e and t h i s has d e p r i v e d the Peromyscus of t h e i r prime fo o d s o u r c e . Most of the specimens were t a k e n from the west c o a s t of the i s l a n d ; here Peromyscus were found l i v i n g around the r o c k b l u f f areas where t i d e p o o l s formed a t low t i d e . A few specimens were t a k e n from the d r i f t - w o o d zone above the sandy beach but none from those r e g i o n s exposed t o the s p r a y pf the P a c i f i c Ocean. The summer of 1970 t r a p r e c o r d i n d i c a t e d t h a t open b r u s h a r e a s , away from the p o l l u t e d shore of B u l l Harbor bay, and c e r t a i n p o i n t s a l o n g the s o u t h e r n c o a s t l i n e y i e l d e d Peromyscus w i t h a t r a p success of around 8 p e r c e n t . The r e m a i n i n g i s l a n d s of the n o r t h e r n sample occur west of Cape S c o t t . Each i s l a n d i s f u l l y exposed to the f u l l a c t i o n of the P a c i f i c and proved t o be a d i f f i c u l t p l a c e to r e a c h and seemed even h a r d e r t o l e a v e . Sox and Lanz I s l a n d s , l o c a t e d about s i x m i l e s west o f Cape S c o t t , are s e p a r a t e d by a channel l e s s than 400 y a r d s wide. T h i s channel i s , however a v e r y e f f e c t i v e b a r r i e r s i n c e the f a s t f l o w i n g t i d e s t h rough t h i s passage keep the water i n a c o n s t a n t s t a t e o f t u r b u l e n c e Mink ( M u s t e l a v i s o n ) i n t r o d u c e d upon Lanz by the P r e d r i c k s e n b r o t h e r s i n 1938 or 1939, i s now common upon b o t h Cox and Lanz I s l a n d s , w h i l e r a c c o o n , (Procyon l o t o r ) , has remained upon Cox I s l a n d . A d i s a s s e m b l e d Sherman L i v e t r a p and an upse t t r a p l i n e were p r o b a b l y the work of the r a c c o o n . E x p e r i e n c e w i t h t r a p -r o b b i n g raccoons on Texada I s l a n d d u r i n g the 1970 t r a p season t o g e t h e r w i t h the i n c i d e n t s on Cox I s l a n d , i n d i c a t e t h a t raccoons are p o t e n t i a l p r e d a t o r s of Peromyscus. Raccoons and the o c c a s i o n a l s c r e e c h owl would be the o n l y p r e d a t o r s of Peromyscus on many of the northern, i s l a n d s . Female Peromyscus were t r a p p e d more f r e q u e n t l y than males i n areas of dense c o v e r . Three of the seven females t r a p p e d away from the beach had d e l i v e r e d t h e i r l i t t e r w h i l e i n the t r a p . I t seems t h a t g r a v i d females about to g i v e b i r t h move away from the beach and seek p r o t e c t i o n of the underbrush. T h i s apparent need f o r p r o t e c t i o n a p p l i e s o n l y f o r the p e r i o d of p a r t u r i t i o n f o r l a c t a t i n g females vere c a p t u r e d a l o n g the i n t e r t i d a l zone as f r e q u e n t l y as any o^her sex or age c l a s s . B e r e s f o r d I s l a n d T h i s i s l a n d , l o c a t e d two and a h a l f m i l e s southwest of Lanz, appears as a s m a l l 320 f o o t r o c k p i n n a c l e . Bad weather and heavy s u r f p r o h i b i t e d the s e t t i n g of t r a p s around the h i g h t i d e mark and the o n l y a l t e r n a t i v e was t o s c a l e the ro c k and s e t t r a p s a c r o s s the 200 f o o t wide f l a t t o p . The gr a s s (Peschampsia c a e s p i t o s a ) was dense over the t o p of the i s l a n d and the t h i n s o i l l a y e r was honeycombed w i t h the burrows of sea b i r d s . Only a young C a s s i n A u k l e t was r e c o v e r e d from our t r a p l i n e and I must concur w i t h the statement made by the p r e v i o u s s c i e n t i f i c p a r t y ( C a r l e_t a l . , 1950) t h a t no s m a l l mammal appears t o i n h a b i t the upper reaches of t h i s i s l a n d . I t i s u n f o r t u n a t e t h a t a beach sample c o u l d not be o b t a i n e d f o r such a s m a l l and i n h o s p i t a b l e h a b i t a t must e x e r t a tremendous s e l e c t i v e p r e s s u r e upon the Peromyscus and the g e n e t i c consequences would be worthy of i n v e s t i g a t i o n . T r i a n g l e I s l a n d T h i s i s l a n d i s unique among the i s l a n d s s t u d i e d . I t s t r e e l e s s s l o p e s are d e n s e l y overgrown w i t h wind-pruned s a l l a l and salmonberry. Peromyscus were found to be abundant i n a l l h a b i t a t s (31.3 p e r c e n t t r a p s u c c e s s ) . F u r t h e r m o r e , these mice were a c t i v e d u r i n g the l a t e a f t e r n o o n as w e l l as a t n i g h t . Twenty t r a p s l a i d a t 3 p.m. August 24, when checked t h a t same a f t e r n o o n a t around 4 p.m., y i e l d e d t h r e e a d u l t mice. At no o t h e r l o c a t i o n have I t r a p p e d Peromyscus a t t h i s time of the day. However, Peromyscus i n h a b i t i n g the Santa B a r b a r a Channel i s l a n d s are a l s o r e p o r t e d t o be d i u r n a J (J. D. Smith p e r s o n a l communication). T h i s d i u r n a l p a t t e r n i s p o s s i b l y due t o the l a c k of p r e d a t o r p r e s s u r e and the h i g h p o p u l a t i o n d e n s i t y . Peromyscus from T r i a n g l e I s l a n d are l a r g e and somewhat a t y p i c a l l y m a n i c u l a t u s - l i k e i n appearance. The v e r y o l d (as i n d i c a t e d by h a v i n g e x t e n s i v e t o o t h wear and b e l o n g i n g to the maximum s i z e c l a s s ) male Peromyscus were t r a p p e d o n l y upon the top of the i s l a n d a t an e l e v a t i o n of 690 f e e t . F i v e of the s i x specimens c a p t u r e d the f i r s t n i g h t i n the apex t r a p l i n e were males of the maximum s i z e c l a s s ; t h e r e i s an apparent absence of these males on the beach. I f t h i s d i s t r i b u t i o n can be c o n s i d e r e d a n a t u r a l b i o l o g i c a l phenomenon and not a chance occurrence t h e n t h i s i s the f i r s t r e p o r t e d case of s e n i o r c i t i z e n s e g r e g a t i o n among Peromyscus. Under l a b o r a t o r y c o n d i t i o n s Peromyscus from T r i a n g l e I s l a n d behave d i f f e r e n t l y from those of most o t h e r i s l a n d s . They are more amicable t o o t h e r i n d i v i d u a l s from t h e i r own and o t h e r i s l a n d l o c a l i t i e s . Peromyscus from T r i a n g l e attempt t o mate j u s t minutes a f t e r b e i n g i n t r o d u c e d t o a s t r a n g e female. A l t h o u g h encounters were never seen t o be consummated a t t h a t t i m e , my o b s e r v a t i o n s suggest t h a t i n a l l cases i t was the n o n - T r i a n g l e p a r t n e r which broke away from the i n t e r a c t i o n . T h i s a m i c a b i l i t y i s s i m i l a r t o the c o n d i t i o n I noted among the Peromyscus from the Santa B a r b a r a Channel I s l a n d s , C a l i f o r n i a . Only i n t h i s l a t t e r case have mixed sex groups been observed l i v i n g i n harmony under l a b o r a t o r y c o n d i t i o n s . Mixed sex communal groups do not form among l a b o r a t o r y p o p u l a t i o n of the n o r t h e r n ' i n s u l a r Peromyscus. A n o t h e r - d i s t i n g u i s h i n g f e a t u r e of the Peromyscus on T r i a n g l e I s l a n d i s t h e i r h a b i t of b u r r o w i n g beneath the l a y e r of sawdust i n . t h e i r l a b o r a t o r y cage. A one i n c h l a y e r of wood s h a v i n g s i s , s u f f i c i e n t t o obscure them from the c a s u a l g l a n c e . I t seems t h a t the l a c k of t r e e s has brought about a s e m i - f o s s o r i a l mode of e x i s t e n c e i n these a n i m a l s , a t r a i t w h i c h i s l e a r n e d and not i n h e r i t e d a c c o r d i n g t o the d a t a a v a i l a b l e f o r i n t e r - i s l a n d c r o s s e s . W i n t e r Guiguet. ( p e r s o n a l communication) has s p e c u l a t e d t h a t i n the w i n t e r Peromyscus m i g r a t e i n l a n d i n o r d e r t o evade what i s b e l i e v e d t o be adverse weather c o n d i t i o n s upon the beaches However, a t r a p l i n e s e t up i n F e b r u a r y on the beach of K e ats I s l a n d , Howe Sound, B r i t i s h Columbia, i n d i c a t e d t h a t Peromyscus i n h a b i t the beaches i n the same d e n s i t y d u r i n g the w i n t e r as i n the summer months ( t a b l e 2 ) . E a r l y May t r a p p i n g i n the i n t e r i o r of the n o r t h e r n i s l a n d s produced no mice. I t seems t h a t these i n s u l a r Peromyscus have adapted to a y e a r round beach environment. Food P r e f e r e n c e s The d i s c o n t i n u o u s d i s t r i b u t i o n of Peromyscus p o p u l a t i o n s ELEVATION # Peromyscus % ANIMAL MATTER CAUGHT \" IN GUT • •' 1 - 1 1 1 — 1 ,'• r •• 5 0 0 f t . -\\S 02 15 3 0 0 f t . OS 22 25 1 0 0 f t , 5^ 22 20 beach 63 5 2 40 Table 2 Keats I s l a n d Peromyscus w i n t e r , 1970 survey a l o n g the c o a s t l i n e o f these i s l a n d s seems to be d i r e c t l y r e l a t e d t o t h e food a v a i l a b l e . As p r e v i o u s l y s t a t e d , a number of specimens were snap-trapped on the beaches of each i s l a n d and i n a l l cases the r e s u l t s of the stomach c o n t e n t a n a l y s i s were the same. E i g h t y p e r c e n t of the stomach c o n t e n t s , f o r the summer sample, c o n s i s t e d of a n i m a l m a t e r i a l . The major p o r t i o n of t h i s was C o l e p p t e r a l a r v a e and amphippds ( O r c h e s t r o i d e a s p p . ) . Those beaches w i t h d a i l y i n f l u x e s of f l o t s a m are more l i k e l y to harbor l a r g e p o p u l a t i o n s of amphipods and t h i s i s b e l i e v e d to be the main a t t r a c t i o n and means of d i e t a r y s u p p o r t f o r the Peromyscus. CONCLUSIONS The w i n t e r o f 1968-1969 was severe and l o n g l a s t i n g . Many n a t u r a l a nimal p o p u l a t i o n s were a d v e r s e l y a f f e c t e d and the r e s u l t i n g low p o p u l a t i o n d e n s i t i e s are c l e a r l y documented by the s p o r t h u n t e r r e t u r n s f o r the 1969 season. I n s u l a r Peromyscus were p r o b a b l y a f f e c t e d i n a s i m i l a r manner and i n 1969 t r a p p i n g r e c o r d may approximate th e minimal p o p u l a t i o n d e n s i t y . The t r a p p i n g l o c a t i o n s , d u r i n g t h i s p e r i o d of severe weather c o n d i t i o n s , may a l s o i n d i c a t e the most f a v o r a b l e environment. The 1970 t r a p p i n g r e s u l t s and s i g h t i n g r e c o r d s suggest a s i g n i f i c a n t l y h i g h e r d e n s i t y o f Peromyscus as w e l l as of o t h e r mammals such as mink, o t t e r and deer. Hope, B a l a c l a v a and Doyle I s l a n d s p r o v i d e d a 10 p e r c e n t , 12 p e r c e n t and 8 p e r c e n t t r a p s u c c e s s , r e s p e c t i v e l y d u r i n g the month of J u l y i n 1970. T h i s . i s c o n s i d e r a b l y above the t r a p success recorde'd f o r 't^ he •same, a r e a d u r i n g the 1969 season ( t a b l e l ) . Weather c o n d i t i o n s s i n c e 1968 have- been m i l d , and the 1970 t r a p r e s u l t s p r o b a b l y r e p r e s e n t a more n a t u r a l p o p u l a t i o n l e v e l . I f t h i s i s the :case, t h e n upon the Gordon and G o l e t a s i s l a n d - g r o u p s Peromyscus d e n s i t i e s , i n f a v o r a b l e l o c a t i o n s , f l u c t u a t e from 1 t o 10 a n i m a l s per 100 y a r d s of beach. T h i s p r e f e r r e d h a b i t a t i s r e p r e s e n t e d by a l i n e a r range s t r e t c h i n g from the w ater's edge up t o an a r e a no f u r t h e r i n t o , the f o r e s t canopy t h a n about t e n f e e t . S e v e r a l mice have been drowned when caught i n t r a p s i n a d v e r t a n t l y s e t below the n i g h t h i g h water mark. A n a l y s i s of the stomach c o n t e n t s t a k e n from the, drowned a n i m a l s r e v e a l e d t h a t these Peromyscus had t e e n f e e d i n g e x c l u s i v e l y upon amphipods. B e n d e l l (1959) has documented the e f f e c t s of weather upon the f e c u n d i t y of. Peromyscus leu c o p u s and has found t h a t a 50 perce'nt r e d u c t i o n i n b i r t h r a t e can be a t t r i b u t e d t o bad weather c o n d i t i o n s even though f o o d i s u n l i m i t e d . I n these n o r t h e r n i s l a n d s ' the a i r temperature and g e n e r a l weathe c o n d i t i o n s would seem t o have l i t t l e e f f e c t upon the m i c r o c l i m a t e of the i n t e r t i d a l zone and t h e r e f o r e the d e n s i t y of amphipods s h o u l d be e x p e c t e d t o remain f a i r l y s t a b l e over these two y e a r s . Indeed, a d d i t i o n a l storms mean \"that e x t r a d e t r i t u s i s washed up on the beaches and t h i s s h o u l d have the eff/ect of i n c r e a s i n g the p o p u l a t i o n s of a v a i l a b l e amphipods and t h e r e f o r e f a v o r -the i n c r e a s e i n Peromyscus d e n s i t y . I n t h i s study the mice- p o p u l a t i o n s are showing a s i m i l a r c y c l e to t h a t d e s c r i b e d by B e n d e l l f o r P. l e u c o p u s , except t h a t the e f f e c t of the weather seems t o be somewhat g r e a t e r . Dpyle I s l a n d , one of the few areas l a c k i n g a beach h a b i t a t c o n s i d e r e d to be f a v o r a b l e to Peromyscus, showed a p o p u l a t i o n d e n s i t y t h a t f l u c t u a t e d t o a g r e a t e r e x t e n t (8 p e r c e n t ) thap t h a t of p o p u l a t i o n s i n h a b i t i n g the more f a v o r a b l e e nvironments. A f l u c t u a t i n g f o o d s u p p l y , which I b e l i e v e i s a c h a r a c t e r i s t i c of the i n l a n d h a b i t a t , would p r o b a b l y account f o r the observed change i n p o p u l a t i o n d e n s i t y . The 1969 t r a p p i n g r e s u l t s i n d i c a t e d t h a t the Peromyscus were not a d v e r s e l y a f f e c t e d by the severe w i n t e r of 1968. I t seems p r o b a b l e t h a t the exposed n a t u r e of the S c o t t I s l a n d s may h a v e a b e n e f i c i a l e f f e c t i n m a i n t a i n i n g a c o n s t a n t p e r e n n i a l w i n t e r weather p r o f i l e , a l b e i t one of severe c o n d i t i o n s by human s t a n d a r d s . . I t would be h a r d t o imagine a h i g h e r d e n s i t y of Peromyscus on T r i a n g l e I s l a n d , f o r the beach zone gave the i m p r e s s i o n of h a r b o r i n g mice i n plague numbers. The t r a p p i n g success of 31 p e r c e n t was t.he h i g h e s t r e c o r d e d f o r any of the i s l a n d s s t u d i e d . I f these adverse y e t a n n u a l l y c o n s i s t e n t , weather c o n d i t i o n s are r e g u l a r , t h e n the S c o t t I s l a n d s s h o u l d m a i n t a i n a f a i r l y s t a b l e d e n s i t y of Peromyscus. P r e d a t i o n * as a means of p o p u l a t i o n c o n t r o l , can be r u l e d out as t h e r e are no known p r e d a t o r s upon T r i a n g l e I s l a n d . P a r a s i t e s were not a problem t o the p o p u l a t i o n ; indeed these mice were remarkably f r e e from any p a r a s i t e . The f a c t o r s w h i c h r e g u l a t e the p a r a s i t e l o a d on these p o p u l a t i o n s of mice are not s o l e l y d e n s i t y dependent, f o r the V a n s i t t a r t I s l a n d p o p u l a t i o n of Peromyscus b e i n g one f o u r t h the d e n s i t y of the T r i a n g l e p o p u l a t i o n had an overabundance of e c t o ^ - p a r a s i t e s . The v e c t o r s and s p e c i f i c causes of p a r a s i t e i n f e s t a t i o n s remain unknown and would o f f e r an i n t e r e s t i n g problem f o r a f u t u r e s t u d y . The extreme t o l e r a n c e and a m i c a b i l i t y of the T r i a n g l e mice t e n d to c r e a t e the i m p r e s s i o n t h a t an i n t r i n s i c s e l f - r e g u l a t o r y mechanism, such as t h a t proposed f o r M i c r o t u s ( C h i t t y , 1952; K r e b s , 1970) does not r e g u l a t e these Peromyscus p o p u l a t i o n s . The beach h a b i t a t and the r e s u l t s of the stomach a n a l y s i s e s t a b l i s h Peromyscus as an i m p o r t a n t i n t e r t i d a l s cavenger. R i c k e t t s and C a l v i n i n t h e i r book \"Between P a c i f i c T i d e s \" (p. 158) mention t h a t the n o c t u r n a l h a b i t s o f O r c h e s t r o j d e a l e s s e n s t h e i r v u l n e r a b i l i t y t o b i r d p r e d a t i o n . They were unaware t h a t t h i s r i c h f o o d source was r e a d i l y b e i n g u t i l i z e d by an e q u a l l y v o r a c i o u s p r e d a t o r . T h i s c a r n i v o r o u s d i e t , c o n t a i n i n g a h i g h p r o p o r t i o n of c h i t o n o u s m a t e r i a l , i s somewhat analagous to t h a t of a c l o s e r e l a t i v e , Qnychomys. The rough c h i t i n o u s d i e t of Onychomys appears to be c o r r e l a t e d w i t h a stomach g l a n d u l a r r e g i o n t h a t i s e n c a p s u l a t e d i n a f u n d i c pouch a f f o r d i n g p r o t e c t i o n t o t h i s s e n s i t i v e a r e a (Horner e_t a l , 1965). E x a m i n a t i o n of the stomach morphology of i n s u l a r Peromyscus i n d i c a t e s t h a t , w i t h one e x c e p t i o n , no s p e c i a l g a s t r i c a d a p t a t i o n t h a t can be c o r r e l a t e d w i t h a h i g h l y c h i t i n o u s d i e t has t a k e n p l a c e i n t l } i s group of m i c e T The stomach i s d i s t i n c t l y b i l o c u l a r w i t h the g l a n d u l a r r e g i o n f u l l y exposed to the stomach c o n t e n t s , s i m i l a r t o the d e s c r i p t i o n g i v e n by V o r o n t s o v (1957). The e x c e p t i o n was n o t e d i n the s i n g l e specimen t a k e n f r o m B a l a c l a v a I s l a n d . T h i s i n d i v i d u a l had a d i s t i n c t p a r t i a l i n v a g i n a t i o n o f t h e g l a n d u l a r r e g i o n . Peromyscus are o p p o r t u n i s t i c . The d e n s i t y of Peromyscus seems t o be d i r e c t l y r e l a t e d t o the f l o r a l , f a u n a l , and h a b i t a t d i v e r s i t y . On the i s l a n d s sampled the beach e n v i r o n -ment i s the p r e f e r r e d h a b i t a t an,d t h i s seems t o be the case throughout the y e a r . MORPHOLOGICAL AND BEHAVIORAL VARIATION IN INSULAR POPULATIONS OP PEROMYSCUS. I n the p r e s e n t study 13 i s l a n d s and two c o n t i n e n t a l p o p u l a t i o n s of Peromyscus m a n i c u l a t u s are a n a l y z e d and c o r r e l a t i o n s of v a r i o u s m o r p h o l o g i c a l measurements are made to a s c e r t a i n the taxonomic s i g n i f i c a n c e of v a r i a t i o n w i t h i n i n s u l a r groups of Peromyscus. The r e s u l t s of t h i s a n a l y s i s are p r e s e n t e d i n t h r e e s e c t i o n s : A) The Peromyscus m a n i c u l a t u s gambeli and P. m a n i c u l a t u s r u b i d u s sample from the west c o a s t of the c o n t i n e n t a l U n i t e d S t a t e s . B) The P. m a n i c u l a t u s g e o r g i e n s i s complex from Bowen, Thormanby, Texada, and Savary I s l a n d s , B r i t i s h Columbia. C) The Gordon, G o l e t a s , and S c o t t I s l a n d groups r e p r e s e n t i n g a complex P. m a n i c u l a t u s group. H a l l (1938), i n a s t u d y of the c o l l e c t i o n made by R. A. Cummings i n 1936 upon the G e o r g i a S t r a i t I s l a n d s of B r i t i s h Columbia, a s s i g n e d a new s u b s p e c i e s t i t l e t o the Peromyscus m a n i c u l a t u s of Savary, Texada, Thormanby, and Bowen I s l a n d s . The a s s i g n e d t a x o n , P. nr. g e o r g i e n s i s , was an attempt t o convey the i m p r e s s i o n t h a t , d e s p i t e the degree of i s o l a t i o n e x i s t i n g between these p o p u l a t i o n s , t h e y p o s s e s s e d v e r y s i m i l a r m o r p h o l o g i c a l c h a r a c t e r i s t i c s w h i c h were s i g n i f i c a n t l y d i f f e r e n t from the a d j a c e n t mainland Peromyscus. The s l i g h t v a r i a t i o n found among these i s l a n d mice was shown t o be a c l i n a l i n v e r s e r e l a t i o n s h i p between the degree of i s o l a t i o n from t h e mainland and the t a i l l e n g t h . McCabe and Cowan (1945) found among t h e i s l a n d s i m m e d i a t e l y to the n o r t h of Vancouver I s l a n d a complex of m o r p h o l o g i c a l l y d i v e r s e Peromyscus i n h a b i t i n g a d j a c e n t i s l a n d s s e p a r a t e d by o n l y a few y a r d s of t r e a c h e r o u s ocean water. These a l l o p a t r i c , but g e o g r a p h i c a l l y n e i g h b o u r i n g , Peromyscus r e p o r t e d l y show no s i m p l e morpho-geographic r e l a t i o n s h i p such as r e p o r t e d f o r P. m. g e o r g i e n s i s . F u r t h e r i n v e s t i g a t i o n comparing the v a r i a t i o n and the r e l a t i o n s h i p between e n v i r o n m e n t a l and geographic f a c t o r s c o u l d v e r y w e l l p e r m i t a b e t t e r i n s i g h t i n t o t h e e v o l u t i o n a r y r e l a t i o n s h i p s of these i n s u l a r r o d e n t s . MATERIALS AND METHODS The c o n t i n e n t a l sample c o n s i s t i n g of 183 s k u l l s of Peromyscus m a n i c u l a t u s r u b i d u s and P. m. gambeli was o b t a i n e d from t h e Museum of V e r t e b r a t e Zoology, B e r k e l e y , C a l i f o r n i a . A l l o t h e r specimens were e i t h e r l i v e t r a p p e d d u r i n g t h e summers of 1968, 1969, and 1970 or came from the c o l l e c t i o n of t h e B r i t i s h Columbia P r o v i n c i a l Museum, V i c t o r i a . Only a d u l t specimens were u t i l i z e d and a d u l t s t a t u s was determined i n t h e manner o u t l i n e d by F o s t e r (1965). Those a n i m a l s , h a v i n g f u l l y e r u p t e d t h i r d m o lars and brown p e l a g e , are a t the stage where t h e y are capable of b r e e d i n g and t h i s was t h e r e f o r e used as the p r i m a r y c r i t e r i o n f o r the c l a s s i f i c a t i o n of a d u l t s t a t u s . F i e l d evidence suggests t h a t these a d u l t specimens are i n t h e i r second y e a r and p a r t i c i p a t i n g i n t h e i r f i r s t b r e e d i n g season. F i g . 4 C o l l e c t i o n l o c a t i o n s f o r the c o n t i n e n t a l samples of Peromyscus m a n i c u l a t u s gambeli and P. m. r u b i d u s C h a r a c t e r s measured: I n o r d e r to a l l e v i a t e any m i s u n d e r s t a n d i n g r e s u l t i n g from a d i f f e r e n c e i n measurement t e c h n i q u e a b r i e f o u t l i n e of the methods used i n t h i s s t u d y i s p r e s e n t e d a t t h i s p o i n t . A) TOTAL LENGTH...determined by p l a c i n g t h e d o r s a l s u r f a c e o f the a n i m a l f l a t upon a m e t r i c r u l e and a p p l y i n g enough t e n s i o n to s t r e t c h the specimen s l i g h t l y so t h a t the backbone i s p a r a l l e l t o t h e r u l e . Measurements were ta k e n f o r t h e d i s t a n c e from the t i p of the nose to t h e end of t h e t a i l d i s r e g a r d i n g the t e r m i n a l t a i l h a i r s . B) TAIL LENGTH...the body was hung over the end o f a m e t r i c r u l e r i n such a way as t o form a 90° angle w i t h the t a i l . T a i l l e n g t h t h e r e f o r e r e p r e s e n t s t h e d i s t a n c e from the f i r s t f r e e c a u d a l v e r t e b r a to the t i p of t h e t a i l , and not i n c l u d i n g the t e r m i n a l h a i r s . C) EAR LENGTH.. .measurements were t a k e n from the bottom of the n o t c h t o the t i p of t h e e a r . D) HIND FOOT LENGTH...this i s the d i s t a n c e from the h e e l t o the end of the l o n g e s t toe and not to the t i p o f the claw. The r o c k y h a b i t a t of most Peromyscus i n v e s t i g a t e d i n t h i s study was c o n s i d e r e d t o be a s i g n i f i c a n t f a c t o r i n the d e t e r m i n a t i o n of claw l e n g t h and f o r comparative a n a l y s i s the d i g i t l e n g t h w i t h o u t the claw was c o n s i d e r e d t o be the more i l l u s t r a t i v e measure. E) BODY LENGTH...the v a l u e o b t a i n e d f r o m s u b t r a c t i n g the t a i l l e n g t h from the t o t a l l e n g t h was used as the body l e n g t h measurement. A l l measurements were t a k e n t o the n e a r e s t h a l f m i l l i m e t e r and a l l d a t a were s t o r e d upon I.B.M. cards f o r computer a n a l y s i s . S k u l l dimensions were t a k e n u s i n g H e l i o s needle p o i n t m e t r i c a l i p e r s t o the n e a r e s t 0.1 m i l l i m e t e r . RESULTS AND DISCUSSION S e c t i o n A: The C o n t i n e n t a l Sample Osgood (1909), i n h i s a n a l y s i s of the Peromyscus m a n i c u l a t u s g a m b e l i , made the f o l l o w i n g statement: \"Specimens from Monterey, the type l o c a l i t y , are a b s o l u t e l y i d e n t i c a l w i t h t h o s e from San Diego and t h e n o r t h e a s t c o a s t of lower C a l i f o r n i a , and t h e i n t e r v e n i n g r e g i o n i s i n h a b i t e d by e x a c t l y the same form.\" T h i s c r e a t e s the i m p r e s s i o n t h a t no v a r i a t i o n e x i s t s w i t h i n t h i s s u b s p e c i e s . I n v e s t i g a t i o n s by Sumner (1918, 1926), C l a r k (1941), and Dice ( l 9 4 0 a , b ) , have shown t h a t e x t e n s i v e v a r i a t i o n e x i s t s w i t h i n each s u b s p e c i e s , y e t s u b s p e c i f i c b o u n d a r i e s a r e a b r u p t i f c e r t a i n s p e c i f i c c h a r a c t e r i s t i c s are c o n s i d e r e d . Sumner (1918) mentions t h a t p i g m e n t a t i o n tends towards c o n t i n u o u s g r a d a t i o n and m o r p h o l o g i c a l measurements show a d i s c o n t i n u o u s d i s t r i b u t i o n . The t a x o n o m i s t has t o judge whether the v a r i a t i o n i s of a magnitude i n d i c a t i v e o f s p e c i f i c or s u b s p e c i f i c l e v e l , and t h i s judgement becomes even more d i f f i c u l t t o make when a l l o p a t r i c , and e s p e c i a l l y i n s u l a r , p o p u l a t i o n s are i n v o l v e d . I have s e l e c t e d P. m. gambeli and P. m. r u b i d u s as the c o n t i n e n t a l s u b s p e c i e s used as t h e c o n t r o l group s i n c e t h e y are among the most e x t e n s i v e l y s t u d i e d . These two s u b s p e c i e s are r e p r e s e n t e d by a l a r g e and r e a d i l y a v a i l a b l e museum c o l l e c t i o n . The range of these s u b s p e c i e s i s a l s o a s o u t h e r n e x t e n s i o n of the g e o g r a p h i c r e g i o n sampled i n t h i s s t u d y . Peromyscus m. gambeli and P. m. r u b i d u s are each r e p r e s e n t e d by samples (n=85 and 98, r e s p e c t i v e l y ) t a k e n from f i v e g e o graphic a r e a s of d i f f e r e n t l a t i t u d e s and encompassing n e a r l y the t o t a l range o f each s u b s p e c i e s , ( f i g . 4 ) . A n a l y s i s of t h e 10 c r a n i a l measurements ( t a b l e s 1A, 2A , appendix l ) , show t h a t i n P. m. gambeli the males are not s i g n i f i c a n t l y d i f f e r e n t from the f e m a l e s . Sexual dimorphism a p p a r e n t l y i s not pronounced i n e i t h e r s u b s p e c i e s and a c c o r d i n g t o Dice (1949) any s e x u a l d i f f e r e n c e i n P. m a n i c u l a t u s i s s l i g h t and does not j u s t i f y s e p a r a t i n g sexes when comparing p o p u l a t i o n s . T h i s c o n t r a s t s w i t h the r e s u l t s r e p o r t e d by Sumner (1926), who found t h a t s e x u a l dimorphism i n P. m a n i c u l a t u s was most n o t i c a b l e i n t o t a l body l e n g t h , w i t h t h e males b e i n g 0.4-3.6 mm. s m a l l e r t h a n the f e m a l e s . The males are a l s o r e p o r t e d to have a h i n d f o o t l e n g t h s i g n i f i c a n t l y g r e a t e r than t h a t of t h e female (Sumner, 1926). Other s p e c i e s are known to have geographic g r a d i e n t s i n s e x u a l dimorphism (Cowan, 1956) and t h e r e f o r e any such v a r i a t i o n w i t h i n t h e i s l a n d sample c o u l d be of, s i g n i f i c a n c e i n e v a l u a t i n g the e f f e c t s of an i s l a n d environment upon Peromyscus morphology. Comparison of the two c o n t i n e n t a l s u b s p e c i e s u s i n g the t e n c r a n i a l measurements show t h a t 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 between s u b s p e c i e s a t the 1 p e r c e n t l e v e l i n seven of the t e n c h a r a c t e r s measured. Sexual dimorphism i n P. m. r u b i d u s , when e v a l u a t e d by comparison of t h e same t e n c h a r a c t e r s , e x i s t s o n l y a t the 5 p e r c e n t or g r e a t e r c o n f i d e n c e l e v e l ( t a b l e s 3A, 4A, appendix l ) . The c h a r a c t e r s u t i l i z e d i n t h i s s t u d y are a p p a r e n t l y not u n d u l y i n f l u e n c e d by s e x u a l d i f f e r e n c e s i n Peromyscus and can be r e l i e d upon t o i n d i c a t e s u b s p e c i f i c v a r i a t i o n . S i g n i f i c a n t v a r i a t i o n o c c u r r e d between sample means (both sexes combined) f o r each l o c a t i o n a n a l y s e d , except i n areas 1 and 2 ( t a b l e 1A, appendix l ) . T h i s v a r i a t i o n i s p r o b a b l y a r e f l e c t i o n of the u n i f o r m i t y of n o r t h e r n C a l i f o r n i a , Oregon, and s o u t h e r n Washington. The s o u t h e r n , G e o r g i a S t r a i t , s t udy i s l a n d s a r e s i t u a t e d i n the C o a s t a l Douglas F i r Zone and the n o r t h e r n s t u d y group i n the C o a s t a l Western Hemlock Zone, both are c o n s i d e r e d t o be i n the Mesothermal B i o g e o c l i m a t i c F o r m a t i o n ( K r a j i n a , 1969). V a r i a t i o n between sample l o c a t i o n s i n each r e s p e c t i v e c l i m a t i c zone i s m i n i m a l b u t c l i m a t i c v a r i a t i o n between the two zones (Csb and Cfb, Koppen c l a s s i f i c a t i o n ) c o u l d be a f a c t o r i n the d i s t r i b u t i o n of Peromyscus s p e c i e s . From t h i s a n a l y s i s of the c o n t i n e n t a l p o p u l a t i o n s s e v e r a l i n f e r e n c e s can be made t h a t a p p l y to the a n a l y s i s of i s l a n d samples. F i r s t , and perhaps the most i m p o r t a n t p o i n t , i s t h a t the degree of v a r i a t i o n , as determined by the r e l a t i v e l y low and c o n s i s t e n t s t a n d a r d d e v i a t i o n and s t a n d a r d e r r o r v a l u e s , i s not b e i n g u n d u l y i n f l u e n c e d by the s m a l l sample s i z e of some i s l a n d c o l l e c t i o n s . S e c o n d l y , a l t h o u g h s i g n i f i c a n t d i f f e r e n c e s o ccur w i t h i n each, group, seven of the t e n c r a n i a l c h a r a c t e r s s e l e c t e d have t h e p o t e n t i a l t o be s i g n i f i c a n t l y d i f f e r e n t a t a l e v e l i n d i c a t i v e of c o n t i n e n t a l s u b s p e c i e s . Sample s i z e s from each of the 13 i s l a n d s were g e n e r a l l y g r e a t e r t h a n those f o r each l o c a t i o n sampled i n t h e two c o n t i n e n t a l s u b s p e c i e s . The s m a l l and c o n s t a n t s t a n d a r d d e v i a t i o n and s t a n d a r d e r r o r v a l u e s (the l a t t e r c o n s i s t e n t l y l e s s than 0.01 p e r c e n t ) f o r both sample s e r i e s a l l o w s f o r d i r e c t comparison of t h e mean average v a l u e s . These d a t a i n d i c a t e t h a t i n t r a - i s l a n d v a r i a t i o n i n c r a n i a l morphology i s comparable t o t h a t found i n some c o n t i n e n t a l p o p u l a t i o n s . S e v e r a l s t u d i e s ( L e r n e r , 1954) have shown t h a t i n b r e d p o p u l a t i o n s have a g r e a t e r degree o f v a r i a t i o n than t h a t found i n o u t - b r e d p o p u l a t i o n s . C o n sequently, the v a r i a t i o n found among the i s l a n d p o p u l a t i o n s r a i s e s two q u e s t i o n s r e g a r d i n g the s i g n i f i c a n c e of the observed d i f f e r e n c e s . F i r s t , the p o s s i b i l i t y a r i s e s t h a t the c h a r a c t e r s measured are not the most s e n s i t i v e markers of the e v o l u t i o n a r y changes t a k i n g p l a c e i n t h i s group of r o d e n t s , and s e c o n d l y , t h a t even the s m a l l e s t i s l a n d i s a \" u n i v e r s e \" t o a mouse p o p u l a t i o n and i n b r e e d i n g e f f e c t s are t h e r e f o r e not a f a c t o r i n the e v o l u t i o n . The f i r s t p o i n t c o u l d not be answered u n l e s s a l l c h a r a c t e r s a r e r e c o r d e d and compared, and t h i s i s a near i m p o s s i b l e t a s k . The second p o i n t can p o s s i b l y be answered by r e f e r r i n g t o the c o n t i n e n t a l p o p u l a t i o n s . I f each sample l o c a t i o n of the c o n t i n e n t a l s u b s p e c i e s can be c o n s i d e r e d an i s l a n d s i t u a t i o n t h e n the s t a n d a r d d e v i a t i o n and e r r o r v a l u e s w o u l d r e f l e c t any d i s c o r d a n c e of c h a r a c t e r s , and perhaps some i d e a of t h e minimum and maximum range t h a t c o n s t i t u t e s an i n b r e d u n i t c o u l d be a s c e r t a i n e d . The c o n t i n e n t a l p o p u l a t i o n s p r e s e n t the same degree of v a r i a t i o n i n t h e i r m o r p h o l o g i c a l p r o f i l e f o r the, t o t a l p o p u l a t i o n as t h e y do f o r each i n d i v i d u a l sample l o c a t i o n . From t h i s I have assumed t h a t each of the s m a l l ranges t r a p p e d d u r i n g the s a m p l i n g of the c o n t i n e n t a l p o p u l a t i o n i s s t i l l an o u t - b r e d u n i t and t h e r e f o r e t h e a r e a of even the s m a l l e s t i s l a n d i s indeed a \" u n i v e r s e \" . T h i s c o n c l u s i o n g a i n s w e i g ht from s t u d i e s u n d e r t a k e n by B e r r y (1964) which show t h a t i n b r e d s t r a i n s of i s l a n d mice, o r i g i n a l l y t a k e n from the same p o p u l a t i o n , have a h i g h e r degree of v a r i a n c e t h a n d i d the o r i g i n a l p o p u l a t i o n . H i s s u g g e s t i o n i s t h a t i s l a n d p o p u l a t i o n s are n o t i n b r e d u n i t s . N i g e i , Hope, T r i a n g l e and Texada I s l a n d s were t r a p p e d i n more t h a n one l o c a t i o n and i n a r e a s where I have assumed a l l o p a t r i c p o p u l a t i o n s e x i s t . No s i g n i f i c a n t c r a n i a l d i f f e r e n c e s occur w i t h i n t h e s e samples w i t h the one e x c e p t i o n : on Texada I s l a n d the c r a n i a l w i d t h of the beach mice i s l a r g e r t h a n t h a t of the mice i n h a b i t i n g the i n t e r i o r of the i s l a n d . The body measurements show a l a r g e r degree of i n t r a - p o p u l a t i o n v a r i a t i o n but t h i s does not seem to be a d v e r s e l y i n f l u e n c e d by the sample s i z e s i n c e t h e v a r i a n c e between samples i s comparable. That i s t o say, the c r i t i c a l minimum sample s i z e has been exceeded i n most of the cases a n a l y s e d . On the b a s i s of body l e n g t h t h e i s l a n d samples are grouped i n t o two c l a s s e s : a) the s o u t h e r n group, c o m p r i s i n g Bowen, Thormanby, Texada and Savary I s l a n d s , and b) the n o r t h e r n group, made up of the r e m a i n i n g n i n e i s l a n d s . S e c t i o n Bt The S o u t h e r n I s l a n d s D i s t i n g u i s h e d by a r e p o r t e d l y s i n g l e phenotype, t h e Peromyscus from Texada, Savary, Thormanby and Bowen I s l a n d s o f f e r a unique o p p o r t u n i t y f o r the s t u d y of v a r i a t i o n i n a l l o p a t r i c p o p u l a t i o n s . The mean average o c c i p i t o n a s a l l e n g t h f l u c t u a t e s -0.4 mm. and comparably low l e v e l s of v a r i a t i o n e x i s t i n each of t h e o t h e r c r a n i a l measurements, ( t a b l e 5A, appendix l ) . Such v a r i a t i o n s are w e l l w i t h i n the e s t i m a t e d t o l e r a n c e of a c o n t i n e n t a l s u b s p e c i e s . H a l l (1938) i n h i s s t u d y of the 1936 R.A. Cummings c o l l e c t i o n e s t a b l i s h e d a c l i n a l i n v e r s e r e l a t i o n s h i p between the degree of i s l a n d i s o l a t i o n from the m a i n l a n d and t h e t a i l l e n g t h . T a i l and body measurements ( t a b l e 3) are d i f f e r e n t f o r each of t h e i s l a n d p o p u l a t i o n s y e t t h e b o d y / t a i l r a t i o ( f i g s . 29A-32A, appendix 2) has a modal v a l u e of 1.0-1.1 f o r a l l i s l a n d s i n t h i s group The m o r p h o l o g i c a l c r i t e r i a upon which the o r i g i n a l taxonomic e v a l u a t i o n vas made i s not r e p r e s e n t a t i v e of the p o p u l a t i o n of Peromyscus upon these i s l a n d s today. The sample used i n t h i s s t u d y i s g e n e r a l l y l a r g e r i n body measurements t h a n t h a t used i n the 1938 study ( t a b l e 3, f i g s . 5,6,7). ISLAND Thormanby Savary Bowen Texada DISTANCE OFF SHORE 3/4 1 2 1/2 2 3/4 m i l e s BODY LENGTH (HALL,1938) 83.0(4) 82.6(14) 78.0(24) 69.2(25) BODY LENGTH (1960-1970) 87.0(22) 81.0(28) 81.9(10) 85.1(37) AVERAGE 86.4(26) 81.7(32) 79.1(34) 78.7(62) (Sample s i z e i n brackets') Table 3 Body l e n g t h s f o r Peromyscus of the G e o r g i a S t r a i t Region. E i g h t specimens t a k e n from Texada I s l a n d i n 1945, when compared w i t h the 1936 and 1968 c o l l e c t i o n s , a r e i n t e r m e d i a t e i n o c c i p i t o n a s a l l e n g t h b u t l a r g e r i n many of the o t h e r s k u l l measurements. The Savary I s l a n d sample has a s l i g h t l y d i f f e r e n t e v o l u t i o n a r y p a t t e r n i n m o r p h o l o g i c a l change and t o g e t h e r these d a t a i n d i c a t e t h a t the p o t e n t i a l f o r s i g n i f i c a n t m o r p h o l o g i c a l f l u c t u a t i o n e x i s t s over a r e l a t i v e l y s h o r t p e r i o d of t i m e . I have o b t a i n e d s k u l l measurements of t h e 1936 c o l l e c t i o n t h a t I o b t a i n e d on l o a n from the Museum of V e r t e b r a t e Zoology, The U n i v e r s i t y of C a l i f o r n i a a t B e r k e l e y . No c l i n e can be e s t a b l i s h e d f o r any of the s k u l l measurements. Indeed, i f changes as l a r g e as those r e c o r d e d i s l a n d d i s t a n c e (mi) t o t a l Pre 1950 1968-1970 88 _ 84 80 '76 72 68 I-THORMANBY 2 4 86.4 83.0 87.0 SAVARY 1 81.7 82.2 81.0 BOWEN <£ 2 TEXADA 21 79.1 78.7 77.7 69.3 81.9 85.1 PRE 1950 I i 2 2\\ 2\\ d i s t a n c e from mainland i n m i l e s . F i g . 5 Changes i n body l e n g t h of P. m. g e o r g i e n s i s , i s l a n d d i s t a n c e (mi ) t o t a l Pre 1950 1968-1970 100 96 92 88 THORMANBY 3. 4 92.3 87. 3 93.2 SAVARY 1 BOWEN TEXADA 2\\ 2} 93.4 94.0 97.8 89.6 92.9 97.5 96.3 96.0 98.0 2* 11 . 2 d i s t a n c e from the mainland i n m i l e s 21 F i g . 6 Changes i n t a i l l e n g t h of P. m. g e o r g i e n s i s , F i g . 7 Changes i n o c c i p i t o n a s a l l e n g t h of Peromyscus m a n i c u l a t u s g e o r g i e n s i s . ( i . e . 16mm. i n body l e n g t h , 7mm. i n t o t a l s k u l l l e n g t h ) can be expected w i t h i n any 32 y e a r p e r i o d i t i s d o u b t f u l i f any c l i n a l r e l a t i o n s h i p c o u l d be e s t a b l i s h e d to r e f l e c t the t r u e b i o l o g i c a l s t a t u s of the group. D i f f e r e n c e s i n m o r p h o l o g i c a l measurements are of the magnitude i n d i c a t i v e of s p e c i e s s e p a r a t i o n and y e t t h e r e i s every p o s s i b i l i t y t h a t i n the nex t decade a r e v e r s a l of the s i t u a t i o n may a r i s e . J u s t how t h i s phenomenon can be i n c o r p o r a t e d i n t o a w o r k i n g f o r m u l a f o r naming i n s u l a r p o p u l a t i o n s remains t o be de t e r m i n e d . S i n c e 1936 t h e r e have been major e c o l o g i c a l changes on the s o u t h e r n i s l a n d s t h a t may c o r r e l a t e w i t h the m o r p h o l o g i c a l changes t h a t have t a k e n p l a c e i n s i t u . Houses and s u p p o r t i n g f a c i l i t i e s have been b u i l t i n c o n s i d e r a b l e numbers upon these s o u t h e r n i s l a n d s i n r e c e n t y e a r s . I f t r a p p i n g success f o r the n o r t h e r n u n i n h a b i t e d i s l a n d s i s i n d i c a t i v e of the o p t i m a l h a b i t a t f o r Peromyscus th e n the l a n d a r e a most h e a v i l y u t i l i z e d by Peromyscus has a l s o been the f a v o r e d type of commercial development. I n the so u t h e r n i s l a n d s the s h a l l o w sandy bays s u i t a b l e f o r dense p o p u l a t i o n s of Peromyscus have l o n g s i n c e been c l e a r e d of s u r r o u n d i n g v e g e t a t i o n and ho u s i n g has been s u b s t i t u t e d i n i t s p l a c e . The o n c e - r e s i d e n t Peromyscus have s u b s e q u e n t l y been d i s p l a c e d from t h i s h a b i t a t and now occur o n l y i n the s u r r o u n d i n g r o c k y h i l l s i d e s . Under these c o n d i t i o n s the change i n e n v i r o n m e n t a l p r e s s u r e s would perhaps have f a v o r e d a change i n gene and phenotype f r e q u e n c i e s . F o s t e r (1965) s p e c u l a t e d t h a t a r o c k y s u b s t r a t e , because i t n e c e s s i t a t e d more c l i m b i n g , f a v o r e d a l o n g e r t a i l f o r b a l a n c e . Horner (1954) h y p o t h e s i z e d t h a t l a r g e r h i n d f e e t and l o n g e r t a i l s are an advantage i n an a r b o r e a l h a b i t a t . A r o c k y s u b s t r a t e l i k e the a rea t h a t the d i s p l a c e d Peromyscus have been f o r c e d t o i n h a b i t c o u l d be c o n s i d e r e d analogous to the a r b o r e a l h a b i t a t r e f e r r e d to by Horner. The samples t a k e n d u r i n g my s t u d y can be a p p l i e d as a t e s t of the t h e o r i e s o f F o s t e r and Horner. The Peromyscus from th e e c o l o g i c a l l y d i s t u r b e d i s l a n d s , Thormanby, Bowen, and Savary, s h o u l d have l o n g e r t a i l s and l a r g e r h i n d f e e t t h a n those Peromyscus from the r e l a t i v e l y untouched Texada I s l a n d p o p u l a t i o n s . The d a t a ( f i g . 6; t a b l e s 6A, 7A, appendix l ) i n d i c a t e a d i s t i n c t i n c r e a s e i n t a i l l e n g t h f o r t h o s e Peromyscus i n h a b i t i n g the d i s t u r b e d i s l a n d s . The f o o t measurement, however, seems to have remained r e l a t i v e l y unchanged. These da t a tends t o s u b s t a n t i a t e the i d e a t h a t increment i n the t a i l , an organ used f o r b a l a n c e , i s an advantage, and t h e r e f o r e f a v o r e d , under c e r t a i n c i r c u m s t a n c e s . As a f u r t h e r means of t e s t i n g t h i s h y p o t h e s i s , the Texada p o p u l a t i o n s were sampled i n two l o c a t i o n s . I have assumed t h a t the f i r s t l o c a t i o n , a beach h a b i t a t w i t h a r o c k y s u b s t r a t e , would show a s e l e c t i v e e f f e c t on appendage l e n g t h i f the F o s t e r and Horner hypotheses are v a l i d i n t h i s c o n t e x t . Comparison of s k u l l measurements ( f i g . 7; t a b l e 8A, appendix l ) show a r e v e r s a l of the g e n e r a l t r e n d of increment i n body d i m e n s i o n s , f o r the s k u l l s i z e s are s m a l l e r i n the beach-d w e l l i n g mice than those of the Peromyscus t r a p p e d i n t h e i n t e r i o r of the i s l a n d . The b o d y - t a i l r a t i o s ( f i g s . 30A-33A, appendix 2) are the same f o r b o t h o f the groups measured. The mean average measurements are l a r g e r f o r most of t h e c h a r a c t e r s measured and i f there i s s e l e c t i o n t h e n i t i s f o r a l a r g e r phenotype and not f o r a s p e c i f i c appendage. Hence, the a d a p t a t i o n hypotheses put f o r t h by Horner and F o s t e r cannot be f u l l y s u b s t a n t i a t e d by my d a t a . Any attempt a t r e d e f i n i n g the s y s t e m a t i c r e l a t i o n s h i p s Of these i n s u l a r r o d e n t s must u t i l i z e d a t a t a k e n from the same l o c a t i o n o v er a p e r i o d of y e a r s , o t h e r w i s e s h o r t term f l u c t u a t i o n s i n p o p u l a t i o n means o f those m o r p h o l o g i c a l measurements used i n t h e taxonomic e v a l u a t i o n w i l l t e n d t o negate a l l attempts a t d e r i v i n g a m e a n i n g f u l p h y l o g e n i c comparison. Should such a study be i m p o s s i b l e then the i n v e s t i g a t o r has no a l t e r n a t i v e t o c r e a t i n g a taxonomic c a t e g o r y broad enough t o a l l o w f o r the i n h e r e n t f l u c t u a t i o n i n p o p u l a t i o n c h a r a c t e r s . 1936 1968 ISLAND N TAIL FOOT N TAIL FOOT* SAVARY 14 90 22.3 18 96 21.0 BOWEN 24 93 21.6 10 96 21.6 THORMANBY 4 87 22.4 26 93 20.9 TEXADA . 25 98 22.3 37 98 21.8 * d i f f e r e n c e i n measurement t e c h n i q u e , does n o t i n c l u d e claw l e n g t h . Table 4 Average t a i l and f o o t measurement f o r 1936 and 1968-1970 c o l l e c t i o n s . S e c t i o n C: The N o r t h e r n I s l a n d s I n t r a - i s l a n d v a r i a t i o n i n the n o r t h e r n i s l a n d s i s comparable t o t h a t o b t a i n e d i n t h e s o u t h e r n sample. I n t r a -i s l a n d v a r i a t i o n s ( t a b l e s 9A, 10A, appendix l ) o f the body dimensions are i n many cases l e s s t h a n the degree of v a r i a t i o n s noted i n the s o u t h e r n p o p u l a t i o n s , y e t the s e d i f f e r e n c e s have been s u f f i c i e n t f o r McCabe and Cowan (1945) and Guiguet (1955) to d e s i g n a t e new s u b s p e c i e s on the n o r t h e r n i s l a n d s . A d i s c r i m i n a n t a n a l y s i s , u s i n g f o u r t e e n c h a r a c t e r s , has been employed t o determine the i n t e r - r e l a t i o n s h i p s o f these i n s u l a r p o p u l a t i o n s . I n employing the computed d i s c r i m i n a n t f u n c t i o n s (appendix 3) I c a t e g o r i z e d each i n d i v i d u a l specimen as t o p r o b a b l e i s l a n d of o r i g i n . The d e v i a t i o n s f r o m t h e known p l a c e of o r i g i n are assumed t o r e f l e c t the a l t e r n a t e i s l a n d p o p u l a t i o n w h i c h i s c l o s e s t t a x o n o m i c a l l y . The degree of i n t e r - i s l a n d r e l a t i o n s h i p i s shown g r a p h i c a l l y i n f i g u r e 8 w i t h the magnitude o f the r e l a t i o n s h i p approximated as a percentage of the t o t a l sample s i z e showing a f f i n i t y t o the a l t e r n a t e i s l a n d l o c a t i o n . I t i s obvious t h a t the s m a l l mice show a c l o s e a f f i n i t y f o r one another w h i l e members of the l a r g e phenotype group a r e a l s o s eemingly r e l a t e d . The d i r e c t i o n of e v o l u t i o n i s not the same f o r a l l i s l a n d s ( t a b l e 5 ) . I t i s not s p e c i f i c i n d i r e c t i o n , such as a g e n e r a l i n c r e a s e i n body s i z e f o r the l a r g e or s m a l l mouse phenotypes, o r f o r the i s l a n d group. The T r i a n g l e I s l a n d sample emphasizes t h i s l a c k o f d i r e c t i o n i n the mode of e v o l u t i o n f o r t h e i r s k u l l dimensions a r e a p p a r e n t l y i n c r e a s i n g i n s i z e a t t h e same time t h a t t h e i r body p r o p o r t i o n s are d i m i n i s h i n g ( t a b l e 5, t a b l e s 11A, 12A, appendix l ) . ISLAND BODY LENGTH SKULL LENGTH DOYLE 1930 • 1970 6. Omm 1930 = 1970 .QOmm HURST 6.0 .06 BALACLAVA 10.0 .04 NIGEI 1.0 .01 HOPE 6.0 .02 COX 1940 >- 1970 11.0 1940 1970 .03 LANZ 7.5 .02 TRIANGLE 4.5 .03 Table 5 Degree and ti m e . : d i r e c t i o n o f m o r p h o l o g i c a l change w i t h Sumner (1918) d e s c r i b e d i n Peromyscus p o l i o n o t u s a c o n d i t i o n where the females were l a r g e r t h a n t h e males i n t o t a l body l e n g t h but s m a l l e r i n f o o t s i z e . The male Peromyscus from D o y l e , H u r s t , B a l a c l a v a , N i g e i , and Hope I s l a n d s are l a r g e r than the females i n t o t a l body l e n g t h but a l l , e x c e p t i n g Doyle I s l a n d p o p u l a t i o n , have a l a r g e r f o o t s i z e . V a n s i t t a r t and T r i a n g l e p o p u l a t i o n s have l a r g e r females both i n body s i z e and f o o t l e n g t h and i t i s o n l y the Cox and Lanz p o p u l a t i o n s t h a t f o l l o w the p a t t e r n d e s c r i b e d by Sumne r . B o d y - t a i l r a t i o s ( f i g s . 21A-33A, appendix 2) i n d i c a t e a co n t i n u o u s n o r t h - s o u t h c l i n e i n modal means from a 0.8 t o a maximum of 1.1. S p e c i f i c modal v a l u e s can be c o r r e l a t e d w i t h 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 of t h e i s l a n d s sampled. I n t e r m e d i a t e b o d y - t a i l r a t i o ' groups are found on Hope and B a l a c l a v a I s l a n d s . These two p o p u l a t i o n s are d e s e r v i n g of d e t a i l e d a n a l y s i s i n the f i n a l e v a l u a t i o n of i n s u l a r e v o l u t i o n i n t h i s a r e a . Peromyscus from B a l a c l a v a , V a n s i t t a r t , Hope, Bowen, Thormanby, Texada, and Savary a r e , i n a l l c h a r a c t e r s measured, w e l l w i t h i n the range of v a r i a t i o n e s t a b l i s h e d f o r a c o n t i n e n t a l s u b s p e c i e s . There i s a s t r o n g r e l a t i o n s h i p between each of the seven i s l a n d s w i t h the e x c e p t i o n o f V a n s i t t a r t , w h i c h l i k e B o y l e , i s m o r p h o l o g i c a l l y d i s t i n c t . The a f f i n i t i e s among the t h i r t e e n i s l a n d s are such as to suggest t h a t c o l o n i z a t i o n of these i s l a n d s was undertaken by two d i s t i n c t m o r p h o l o g i c a l s t o c k s , one a s m a l l - b o d i e d and the o t h e r a l a r g e - b o d i e d form ( f i g . 9 ) . I f the d a t a p r o v i d e d by Sheppe ( l 9 6 l ) and McCabe and Cowan (1945) h o l d t rue f o r the n o r t h e r n c o a s t of B r i t i s h Columbia, t h e n i t i s p o s s i b l e t h a t the numerous l a n d s l i d e s are l a u n c h i n g two phenotypes i n t o the ocean. Ocean c u r r e n t s are such t h a t , a t c e r t a i n times o f the y e a r , any r a f t s e t a d r i f t i n the n o r t h e r n r e g i o n w o u l d move s o u t h and s t a n d a good chance o f b e i n g washed up on one of the i s l a n d s i n my study a r e a . Sheppe e s t a b l i s h e d the 500 f t . l e v e l as the e l e v a t i o n where Peromyscus m a n i c u l a t u s i s r e p l a c e d by P. o r e a s . I have p e r s o n a l l y w i t n e s s e d the r e s u l t s of many l a n d s l i d e s a l o n g the steep f j o r d s of B r i t i s h Columbia t h a t have denuded v e r t i c a l d i s t a n c e s i n excess of 500 f t . McCabe and Cowan r e p o r t t h a t P. oreas and P. a u s t e r u s occur a t sea l e v e l a t Loughborough I n l e t , a f j o r d a p p r o x i m a t e l y 170 m i l e s n o r t h of Vancouver. T h e r e f o r e i n both s t u d i e s i t i s apparent t h a t the two m o r p h o l o g i c a l l y d i s t i n c t i v e forms ( t a b l e 6) c o u l d be r e s p o n s i b l e f o r the f o u n d i n g of the observed d i m o r p h i c i s l a n d p o p u l a t i o n s . Peromyscus s i t k e n s i s Merriam, another v e r y l a r g e form of i s l a n d mouse, i n h a b i t s the S i t k a , A l a s k a , r e g i o n . The P. s i t k e n s i s morphotype, known b o t h as P. s i t k e n s i s p r o v e s t e n s i s ( H a l l and K e l s o n , 1959) and P. m a n i c u l a t u s p r o v e s t e n s i s (Cowan and Gu i g u e t , 1965), i n h a b i t s the g e o g r a p h i c a l l y i n t e r m e d i a t e r e g i o n between A l a s k a and the n o r t h e r n s t u d y i s l a n d s . This l a r g e morphotype i s another p o s s i b l e l i n k . i n the d i s p e r s a l o f the d i m o r p h i c a n c e s t r a l s t o c k t h a t I b e l i e v e t o be r e s p o n s i b l e f o r the s t u d y - i s l a n d c o l o n i z a t i o n . BODY TAIL FOOT ' PEROMYSCUS SITKENSIS 219 mm 104 mm 26 mm H a l l and K e l s o n PEROMYSCUS OREAS 204 mm 109 mm 23 mm Cowan and Guiguet P.M. AUSTERUS 176 89 21 Cowan and Guiguet LARGE MORPHOTYPE(A) 213 104 25 SMALL MORPHOTYPE(B) 183 95 21 Table 6 Mean body measurements f o r Peromyscus o f the c o a s t a l r e g i o n of B r i t i s h Columbia. 128 126 124 BRITISH COLUMBIA F i g . 9 D i s p e r s a l r o u t e o f a n c e s t r a l P e r o m y s c u s Two c o h o r t s would p r o v i d e a b i o l o g i c a l l y m e a n i n g f u l arrangement t h a t i n d i c a t e s the e v o l u t i o n a r y p a t t e r n of these i s l a n d groups. T h i s d i v i s i o n c r e a t e s a problem as t o the proper taxonomic d e s i g n a t i o n a p p l i c a b l e to t h e two c o h o r t s , and t h e r e i s a need f o r a d d i t i o n a l d a t a b e f o r e t h i s h y p o t h e s i s can be d e v e l o p e d f u r t h e r . C r y p t i c c h a r a c t e r s , such as the b a c u l a and k a r y o t y p e , have proven t o be o f taxonomic h e l p , and I now have evidence t o p r e s e n t t h a t the b r e e d i n g i n t e r a c t i o n s w i t h i n and between t h e s e two forms are s i g n i f i c a n t f a c t o r s p e r t a i n i n g to t h e r e - e v a l u a t i o n of the s y s t e m a t i c s of these i s l a n d mice. BREEDING TESTS AND COMPARATIVE POSTNATAL DEVELOPMENT OP INSULAR AND INTER-ISLAND HYBRID PEROMYSCUS L a b o r a t o r y h y b r i d i z a t i o n between i s l a n d s t o c k s was undertaken to a s c e r t a i n the c h a r a c t e r i s t i c s of s i z e i n h e r i t a n and the degree of s t e r i l i t y between the v a r i o u s Peromyscus morphotypes found upon the S c o t t , Gordon and G o l e t a s , and G e o r g i a S t r a i t i s l a n d groups. Dice (1940) found t h a t a complete range i n f e r t i l i t y e x i s t s w i t h i n t h e genus Peromyscus. S p e c i e s groups (Osgood, 1909) e x h i b i t i n t e r g r o u p s t e r i l i t y whereas s u b s p e c i e s are i n most cases c o m p l e t e l y f e r t i l e . This s t u d y has extended the i n v e s t i g a t i o n o f i n t e r p o p u l a t i o n f e r t i l i t y by a t t e m p t i n g to c r o s s b r e e d Peromyscus t a k e n from a l l o p a t r i c , and i n many cases m o r p h o l o g i c a l l y d i s t i n c t i v e , p o p u l a t i o n s . G i v e n the c h o i c e , Peromyscus m a n i c u l a t u s have a s t r o n g s e x u a l p r e f e r e n c e f o r members of t h e i r own s p e c i e s ( B l a i r and Howard, 1944). Moore (1965) found evidence s u g g e s t i n g t h a t o l f a c t o r y cues were r e s p o n s i b l e f o r the i s o l a t i o n o f P. m a n i c u l a t u s from P. p o l i o n o t u s . I f . the two i n s u l a r forms i n h a b i t i n g the c o a s t a l i s l a n d s of B r i t i s h Columbia show p r e -f e r e n t i a l mating or i n t e r g r o u p s t e r i l i t y t h e n the case f o r taxonomic r e v i s i o n w i l l be s t r e n g t h e n e d . MATERIALS AND METHODS Peromyscus were o b t a i n e d from the i s l a n d s (see c h a p t e r 1 8 • 2 TRIANGLE COX LANZ HOPE NIGEI VANSITTART BALACLAVA HURST DOYLE TEXADA THORMANBY P.m.austerus HH S3 M H o PH EH >H PH S3 O in EH 4 4 1 fH CD -P m ej ,PH*L EH O o CM 1 2 1 ^ Texada 91%° V a n s i t t a r t 48% 52% Mate p r e f e r e n c e s . FEMALE Cox MALE Cox T r i a n g l e •Cox 7% 93% 44% 56% 16% I s l a n d females show a s t r o n g p r e f e r e n c e f o r a male t a k e n from the same i s l a n d ( t a b l e 10, cases nos. 1, 2, 3, 4, 5.) and i f one i s not a v a i l a b l e t h e n the c h o i c e i s made i n f a v o r of a male from the n e a r e s t geographic l o c a t i o n ( t a b l e 10, nos. 4, 6) Whether an o l f a c t o r y or an a u d i t o r y cue i s r e s p o n s i b l e f o r t h i s s e l e c t i v i t y has not been determined. However, i t i s obvious t h a t a d e f i n i t e p a t t e r n of s e l e c t i v i t y e x i s t s and t h i s c o u l d have a s t r o n g i n f l u e n c e upon the c r o s s b r e e d i n g performances i n my l a b o r a t o r y e x p e r i m e n t s . , The low l e v e l of h y b r i d i z a t i o n , the d e l a y e d development of the h y b r i d young, and the s e l e c t i v e b r e e d i n g groups are i n d i c a t i v e of s t r o n g i s o l a t i n g b a r r i e r s t h a t e x i s t w i t h i n the i s l a n d complex. This r e i n f o r c e s my v i e w , a l s o s t a t e d i n o t h e r c h a p t e r s , t h a t the c u r r e n t taxonomic arrangements are q u e s t i o n -a b l e and t h a t e v o l u t i o n beyond the s u b s p e c i e s l e v e l i s perhaps a r e a l i t y i n t h i s c ase. THE PHALLUS AND ITS BEARING UPON THE CLASSIFICATION OF THE INSULAR PEROMYSCUS OF BRITISH COLUMBIA W i t h i n the genus Peromyscus p h a l l i c morphology has taxonomic importance a t the s p e c i e s l e v e l (Hooper, 1958, 1959). E i g h t e e n s p e c i e s i n v e s t i g a t e d by Hooper (1958) showed v a r i a t i o n i n a b s o l u t e or r e l a t i v e s i z e i n p a r t s of the p h a l l u s . C l o s e l y r e l a t e d s p e c i e s had the most m o r p h o l o g i c a l l y s i m i l a r p h a l l i . I n t e r s p e c i f i c v a r i a t i o n has been d e s c r i b e d as b e i n g absent or v e r y s u b t l e , r e q u i r i n g a l a r g e sample and more r e f i n e d p r o cedures i n orde r t o f i n d s t a t i s t i c a l l y v a l i d c o r r e l a t i o n s between p h a l l i c v a r i a t i o n and the s u b s p e c i f i c t a x a . P h a l l i c d i f f e r e n c e s between s p e c i e s has been the b a s i s of the c r i t i c i s m of the Osgood (1909) c l a s s i f i c a t i o n o f the genus Peromyscus (Hooper and Musser, 1964). Hooper (1958, p. 2 2 ) , u t i l i z i n g the p h a l l u s c h a r a c t e r i s t i c s of P. c r i n i t u s , p l a c e s i t i n the subgenus Peromyscus and not i n the subgenus Haplomylomys as d i d Osgood. He a l s o c l a i m s t h a t h y l o c e t e s s h o u l d p r o b a b l y be removed from the Peromyscus subgenus and p l a c e d i n the Haplomylomys group. I f the degree o f v a r i a t i o n d e s c r i b e d i n p h a l l u s morphology i s a c c e p t e d as s p e c i e s s p e c i f i c w i t h i n the subgenus Peromyscus t h e n comparable v a r i a t i o n s between p o p u l a t i o n s , such as the i n t e r - i s l a n d s i t u a t i o n examined i n my s t u d y , would j u s t i f y taxonomic r e - e v a l u a t i o n o f those groups. MATERIALS AND METHODS Specimens used i n t h i s s t u d y were o b t a i n e d from t r a p and b r e e d i n g c o l o n y deaths of a d u l t males. The d i s t a l p a r t of the p e n i s was removed and s t o r e d i n 70 p e r c e n t e t h a n o l . The p e n i s was c l e a r e d by s o a k i n g i t i n a 2 p e r c e n t s o l u t i o n of p o t a s s i u m h y d r o x i d e f o r t h r e e days. F u r t h e r c l e a r i n g was o b t a i n e d by p l a c i n g i t i n 50 p e r c e n t aqueous g l y c e r i n e s o l u t i o n f o r two days p r i o r to t r a n s f e r r i n g f o r s t o r a g e i n 100 p e r c e n t g l y c e r i n e . The p h a l l u s w a s . s t a i n e d on the t h i r d day of the KOH t r e a t m e n t by the a d d i t i o n of a few drops of A l k a l i n e A l i z e r i n Red s t a i n to the KOH s o l u t i o n . The o u t e r t i s s u e l a y e r , p o s s e s s i n g the s p i n e s c h a r a c t e r i s t i c of Peromyscus p h a l l i , i s e a s i l y l o s t d u r i n g t h i s c l e a r i n g p r o c e s s and I now c o n s i d e r t h a t a p r e t r e a t m e n t i n f o r m a l i n f o r the day p r i o r to a l c o h o l p r e s e r v a t i o n would a l l e v i a t e t h i s problem. The degree of p h a l l i c d i s t o r t i o n was not c a l i b r a t e d s i n c e the i n v e s t i g a t i o n i s i n t e n d e d to be comparative i n n a t u r e and I assumed t h a t each p h a l l u s would d i s t o r t i n a q u a n t i t a t i v e l y s i m i l a r manner. The f o l l o w i n g measurements were made on each of the p r e p a r e d specimens: D i s t a l t r a c t l e n g t h - the l e n g t h from the t i p to the p r o x i m a l p o i n t of f l e x u r e . Glans l e n g t h - the d i s t a n c e from the t i p to the p o i n t where the prepuce a t t a c h e s to the p h a l l u s . Glans d i a m e t e r - the w i d t h of the g l a n s a t the w i d e s t p o i n t . I n the specimens examined t h i s was the r e g i o n around the. meatus u r i n a r i u s . Baculum length-- the g r e a t e s t s t r a i g h t l i n e l e n g t h of the baculum. C a r t i l a g e t i p l e n g t h - the t r a n s l u c e n t c a r t i l a g e n o u s t i p on t h e d i s t a l end o f the baculum was measured to the n e a r e s t .01 but due to i t s s m a l l s i z e and the r e s u l t i n g l a r g e s t a n d a r d e r r o r t h i s measurement i s b e l i e v e d to be of q u e s t i o n a b l e v a l u e . The p r o x i m a l end of the baculum was c a t e g o r i z e d as to one of two t y p e s , e i t h e r t h a t of a diamond (type A) or of a knob (type B, f i g . 12). Three v e n t r a l l a p p e t t y p e s are r e c o g n i z e d i n the sample ( f i g . 12, C, D, E) as w e l l as two d o r s a l l a p p e t v a r i a t i o n s ( f i g . 12, F, G). The d i s t a l t i p o f the g l a n s appears i n two forms: the smooth and the bulbous types ( f i g . 10, H, I ) . I n o r d e r t o determine the presence of s p i n e s i t was n e c e s s a r y to observe f r e s h m a t e r i a l and F i g . 11 The p h a l l u s of Peromyscus m a n i c u l a t u s 2. VENTRAL LAPPETS 3. DORSAL LAPPETS B u l b o u s 4. DISTAL PORTION OF GLANS F i g . 1 2 PHALLIC CHARACTERS c o n s e q u e n t l y no p r e s e r v e d specimens are on d e p o s i t . The p r o c e s s e d p h a l l i are on d e p o s i t i n The V e r t e b r a t e Museum c the U n i v e r s i t y of B r i t i s h Columbia. ISLAND Doyle H u r s t B a l a c l a v a N i g e i V a n s i t t a r t Hope Cox Lanz T r i a n g l e Texada PEROMYSCUS MANICULATUS LOCATION SUBSPECIES* N.W. d o y l e i saxamans b a l a c l a v a i s o l a t u s ** b a l a c l a v a c a r l i c a r l i t r i a n g u l a r i s g e o r g i e n s i s g e o r g i e n s i s 50°127 50°127 50°127 50°127 50°127 50°127 50°128 50°128 50°129 49°124 49°123 Thormanby * Cowan and G u i g e t , 1965 Peromyscus from t h i s i s l a n d have not been d e s c r i b e d or named a t t h i s t i m e . Table 11 P h a l l i c specimens examined. RESULTS AND CONCLUSIONS The g e n e r a l morphology of the p h a l l u s of the i n s u l a r Peromyscus s t u d i e d does not d i f f e r s i g n i f i c a n t l y from the d e s c r i p t i o n g i v e n f o r the c o n t i n e n t a l forms of t h i s genus (Hooper, 1958). The g l a n s i s bulbous around the meatus u r i n a r i u s and t a p e r s to a smooth p r o t u s i b l e t i p w h i c h may or may not t e r m i n a t e i n a s l i g h t s w e l l i n g . S p i n e s , r e s e m b l i n g minute rose t h o r n s , cover t h e p h a l l u s p r o x i m a l to the f l u t e d edge of the meatus u r i n a r i u s . The baculum i s a s l e n d e r osseous rod w i t h a b l u n t d i s t a l t i p and t e r m i n a t e s p r o x i m a l l y i n e i t h e r a diamond or knob shaped s w e l l i n g . Hooper ( p e r s o n a l communication) c o n s i d e r s t h a t t h i s v a r i a t i o n i n the t e r m i n a l p o r t i o n of the baculum i s a f u n c t i o n of age. My r e s u l t s d6 not s u pport t h i s v i e w . The v a r i a t i o n i n the t e r m i n a l p o r t i o n o f the baculum was found i n a l l age groups and i s not a f u n c t i o n o f age. A l l specimens d i s c u s s e d i n t h i s s t u d y were e i t h e r of known a d u l t age c a t e g o r y or had a d u l t pelage and s u f f i c i e n t t o o t h wear ro r e g i s t e r as c l a s s t h r e e , a d u l t , i n the F o s t e r s c a l e f o r age d e t e r m i n a t i o n ( F o s t e r , 1965, p. 6 9 ) . D e s c r i p t i o n of p h a l l i Doyle I s l a n d The p h a l l u s i s one of the l a r g e s t p r e s e n t i n t h i s i s l a n d s u r v e y . Two t h i r d s of the sample d i d not have the s w o l l e n p r o t r u s i b l e t i p to the g l a n s . The v e n t r a l l a p p e t s are m e d i a l l y d i v i d e d . Both types of d o r s a l l a p p e t s , the cone and r i d g e v a r i a t i o n s , o c c u r , but i n a l l cases the organ i s b i l a t e r a l l y s y m m e t r i c a l . The baculum i s not c u r v e d and t e r m i n a t e s a t the p r o x i m a l end w i t h e i t h e r the diamond (type A, f i g . 12) or the b l u n t ( t y p e B , f i g . 12) v a r i a t i o n . H u r s t I s l a n d The p h a l l i are the same as those from Doyle i n o v e r a l l s i z e y e t the v e n t r a l l a p p e t s are of the n o n - d i v i d e d v a r i e t y , g i v i n g the p h a l l u s a d i s t i n c t i v e t r a i t . The d o r s a l l a p p e t s are of the r i d g e type and the organ i s s y m m e t r i c a l . The baculum i s s t r a i g h t and t e r m i n a t e s w i t h the diamond c o n f i g u r a t i o n . B a l a c l a v a I s l a n d A s m a l l p h a l l u s of u n i f o r m diameter a l o n g i t s t o t a l l e n g t h i m p a r t s a unique c h a r a c t e r to t h i s i s l a n d Peromyscus. I n a l l b u t one of the samples the p r o t r u s i b l e p a r t of the g l a n s t e r m i n a t e s w i t h o u t any s w e l l i n g . U n l i k e the o t h e r i s l a n d groups s t u d i e d a l l t h r e e v a r i a t i o n s of the v e n t r a l l a p p e t s o c c u r , whereas the d o r s a l l a p p e t s were a l l of the cone t y p e . I n many cases t h r e e or more cone l a p p e t s occur per p h a l l u s and i n a l l cases the p h a l l u s i s n o n - s y m m e t r i c a l . The baculum i s s t r a i g h t and t h r e e q u a r t e r s of the sample have the b l u n t baculum t e r m i n u s . N i g e i I s l a n d Peromyscus from N i g e i have a l a r g e p h a l l u s w i t h a r e l a t i v e l y l o n g e r g l a n s s e c t i o n t h a n those from e i t h e r Doyle or Hurst I s l a n d s . The g l a n s tends t o be bulbous over the c e n t r a l s e c t i o n p r o x i m a l t o the meatus u r i n a r i u s . I n c r o s s s e c t i o n the g l a n s appears square, i . e . the d o r s a l and v e n t r a l s u r f a c e s of the gl a n s are f l a t . The p r o t r u s i b l e t i p of the g l a n s i s l o n g e r t h a n t h a t found i n any o t h e r i s l a n d sample. The mean d i s t a n c e from the meatus u r i n a r i u s t o the d i s t a l t i p of the g l a n s i s 0.34 cm and averages 0.08 cm l o n g e r than t h a t found i n any o t h e r group. The d i s t a l t i p s are bulbous i n a l l c a s e s . The v e n t r a l l a p p e t s i n two t h i r d s of the sample are u n d i v i d e d and the r e s t are of the p a r t i a l l y d i v i d e d t y p e . The d o r s a l l a p p e t s are i n the r a t i o of 7:1,ridge t o cone. B i l a t e r a l symmetry occu r s i n a l l c a s e s . The baculum i s of the type p r e v i o u s l y d e s c r i b e d f o r H u r s t I s l a n d . V a n s i t t a r t I s l a n d T h i s i s the s m a l l e s t of a l l the p h a l l i groups measured. Most of the p h a l l i p ossess the nonbulbous g l a n s t i p and v e n t r a l l a p p e t s are s e p a r a b l e i n t o a l l t h r e e d i v i s i o n s . The d o r s a l l a p p e t s are of the cone and r i d g e t y p e s . I n those w i t h the cone morphology the symmetry i s b i l a t e r a l . Hope I s l a n d The pronounced decrease i n the p h a l l u s d iameter p r o x i m a l l y to the meatus u r i n a r i u s produces a c o n d i t i o n o p p o s i t e t o t h a t d e s c r i b e d f o r N i g e i I s l a n d . I n a l l c a s e s , the p h a l l u s t e r m i n a t e s a t the d i s t a l t i p w i t h a s l i g h t s w e l l i n g . The l a p p e t s on the v e n t r a l s u r f a c e are n e a r l y a l l of the non-d i v i d e d t y p e , o n l y f o u r of the n i n e t e e n - a p p e a r e d p a r t i a l l y d i v i d e d . A p p r o x i m a t e l y t h r e e q u a r t e r s of the d o r s a l l a p p e t s are of the r i d g e t y p e . The baculum i s s t r a i g h t and t e r m i n a t e s w i t h the diamond shaped head. Cox I s l a n d T h i s l a r g e p h a l l u s type tends to be l a t e r a l l y compressed and appears v e r y t h i n . The non-bulbous terminus to the g l a n s predominates i n the sample. The v e n t r a l l a p p e t s are s p l i t i n t o the n o n - a n d - p a r t i a l l y d i v i d e d c a t e g o r i e s and the d o r s a l l a p p e t s a r e , w i t h hut one e x c e p t i o n , of the r i d g e v a r i e t y . One of the b a c u l a appeared cur v e d . A l l b a c u l a had the diamond shaped t e r m i n u s . Lanz I s l a n d The p h a l l u s i s i n the same s i z e c l a s s as t h a t of Cox I s l a n d but i n t h i s case the tendency f o r l a t e r a l compression i s g r e a t e r . N o n - d i v i d e d v e n t r a l l a p p e t s predominate and one t h i r d of the d o r s a l l a p p e t s are of the cone t y p e . The cone l a p p e t s g i v e a n o n-symmetrical appearance t o the p h a l l u s . The baculum has a s l i g h t curve w i t h the b o t h ends v e n t r a d t o the p h a l l u s c e n t e r l i n e . T r i a n g l e I s l a n d Peromyscus from T r i a n g l e I s l a n d have the l a r g e s t p h a l l i . T h i s s y m m e t r i c a l organ t e r m i n a t e s w i t h a bulbous t i p t o the g l a n s . A l l v e n t r a l l a p p e t s , w i t h but one e x c e p t i o n , are d e e p l y m e d i a l l y d i v i d e d . The e x c e p t i o n , a type D ( f i g . 1 2 ) , i s d i v i d e d b u t t o a f a r l e s s e r degree. The baculum i s s t r a i g h t w i t h the b l u n t v a r i e t y of t e r m i n a l s w e l l i n g . The s o u t h e r n i s l a n d group i s r e p r e s e n t e d i n t h i s s t u d y by specimens t a k e n from Texada and Thormanby I s l a n d s . The p h a l l u s i s e s s e n t i a l l y the same f o r b o t h p o p u l a t i o n samples. I t i s a s m a l l p h a l l u s but l a r g e r t h a n t h a t of the Hope, B a l a c l a v a and V a n s i t t a r t p o p u l a t i o n s t h a t a r e , i n o t h e r c h a r a c t e r s , q u i t e s i m i l a r . The ter m i n u s of the g l a n s i s e i t h e r bulbous or p l a i n , w i t h e q u a l f r e q u e n c y . The v e n t r a l i l a p p e t s are n e a r l y a l l u n d i v i d e d and the d o r s a l l a p p e t s are m o s t l y of the diamond c o n f i g u r a t i o n . Among the 95 p h a l l i examined i n t h i s s t u d y 66 p e r c e n t have a bulbous t e r m i n u s to the g l a n s , 66 p e r c e n t have r i d g e type d o r s a l l a p p e t s , 56 p e r c e n t have u n d i v i d e d v e n t r a l l a p p e t s and 82 p e r c e n t have a baculum t e r m i n a t i n g w i t h the diamond c o n f i g u r a t i o n . The preponderance of u n d i v i d e d v e n t r a l l a p p e t s c o n t r a s t s w i t h the statement by Hooper (1958) t h a t i n P. m a n i c u l a t u s the m e d i a l l y c l e f t v e n t r a l l a p p e t c o n d i t i o n i s uncommon. The p h a l l i c measurements are c o n t r a s t e d w i t h those made by Hooper (1958); they are s i g n i f i c a n t l y d i f f e r e n t . HIND CARTILAGE Hooper 1958 N FOOT GLANS BACULA TIP A B C P.maniculatus 3 20 7.4 8.3 0.8 37 16 41 P.leucopus 5 21 7.8 9.0 0.8 37 24 43 P . p o l i o n o t u s 3 17 6.1 6.6 0.5 36 18 39 I s l a n d samples P.maniculatus 95 22. 5 8.5 9.7 1.25 37.8 22.4 43 V a n s i t t a r t I s . 11 20 7.4 8.4 1.3 37 24.4 42 Legend A g l a n s / f o o t r a t i o B diameter of g l a n s / g l a n s l e n g t h r a t i o C baculum/foot r a t i o Table 12 P h a l l i c measurements f o r s e v e r a l s p e c i e s of Peromyscus. Texada Thormanby T r i a n g l e N i g e i H u r s t Doyle Cox Lanz B a l a c l a v a Hope Vans i t t a r i j P i g 13 COMPARATIVE GLANS LENGTHS 6.5 7.0 7.5 8.0 8.5 9.0 9.5 1.00 1.05 Thormanby Texada Hope B a l a c l a v a 72 T r i a n g l e H u r s t 1.17 Doyle I 1 „ 1.29 # N i g e i r Lanz -7?~ 1.28 Cox j 1 V a n s i t t a r t F i g 14 COMPARATIVE BACULAR LENGTHS 7.5 8.0 3. 5 9-0 9. 5 1.00 1.05 1 .10 1 . 1 5 mean 2 s t a n d a r d f ^ j \" e r r o r s range 1 ^ A f t e r D i c e and Ler.aas, 1 936. The p h a l l u s i s s i g n i f i c a n t l y l a r g e r ( < . 0 l ) than the mean f o r P. m a n i c u l a t u s (Hooper 1958). However, the d i s t a l t r a c t l e n g t h and the baculum l e n g t h show a d i r e c t c o r r e l a t i o n to the s i z e of the a n i m a l . The apparent s i z e d i f f e r e n c e s ( f i g s . 13, 14) are a f u n c t i o n o f t o t a l a n i m a l s i z e and cannot be c o n s i d e r e d as an independent v a r i a b l e i n d i c a t i v e of phylogeny or taxonomy. R e g r e s s i o n a n a l y s i s o f the i n s u l a r d a t a i n d i c a t e s a 91 p e r c e n t c o r r e l a t i o n • b e t w e e n the b a s a l s k u l l l e n g t h , (used i n t h i s s tudy as an i n d i c a t o r o f t o t a l a n i m al s i z e ) and the l e n g t h of the baculum. T h i s r e l a t i o n s h i p i s e x p r e s s e d as f o l l o w s : B a s a l s k u l l length=0.763 x baculum l e n g t h + (-0.658). P. p o l i o n o t u s , b e l i e v e d to be a r e c e n t d e r i v a t i v e of the P. m a n i c u l a t u s complex (Hooper 1958) shows a c l o s e r r e l a t i o n -s h i p to c o n t i n e n t a l P. m a n i c u l a t u s than i s shown by the i s l a n d samples. T h i s p r e s e n t s two p o s s i b l e hypotheses, e i t h e r (a) the sample s i z e (n=3) used by Hooper i s inadequate and not r e p r e s e n t a t i v e of the s p e c i e s m a n i c u l a t u s , or (b) the i n s u l a r Peromyscus of B r i t i s h Columbia are not of the s p e c i e s m a n i c u l a t u s . The former h y p o t h e s i s seems the more p l a u s i b l e i f i t were not t h a t the V a n s i t t a r t mice, a l t h o u g h a p p r o x i m a t i n g the c o n t i n e n t a l Peromyscus m a n i c u l a t u s i n s i z e , d i f f e r c o n s i d e r a b l y from the p h a l l i c dimensions l i s t e d by Hooper. I f t h e observed d i f f e r e n c e s i n t h e g l a n s d i a m e t e r i s a r e a l d i f f e r e n c e and not an a r t i f a c t of the s m a l l sample s i z e t h e n the v a r i a t i o n spans the range of t e n of the s p e c i e s c a t e g o r i z e d by Hooper. Not a b l e e x c e p t i o n s to the g e n e r a l morphology of the p h a l l u s from my i n s u l a r sample are as f o l l o w s : Doyle I s l a n d mice have m e d i a l l y c l e f t v e n t r a l l a p p e t s i n a l l p h a l l i examined. The p h a l l i o f the mice from B a l a c l a v a , b e s i d e s b e i n g s h o r t and t h i c k e r t h r o u g h the g l a n s , have cone type l a p p e t s on the d o r s a l s u r f a c e , and a l l t h r e e t y p e s o f v e n t r a l l a p p e t s are p r e s e n t . E i g h t y - s i x p e r c e n t o f the T r i a n g l e sample have b a c u l a r t e r m i n a t i n g p r o x i m a l l y w i t h the b l u n t end t y p e , and a l l p ossess d i s t i n c t cleavage of the v e n t r a l l a p p e t s . The p h a l l i of T r i a n g l e , Texada, and B a l a c l a v a mice show a h i g h percentage of the supposedly j u v e n i l e t r a i t , the b l u n t baculum t e r m i n u s . R e s u l t s of a T - t e s t a n a l y s i s of the baculum and d i s t a l t r a c t measurements ( f i g s . 19A, 20A, appendix l ) p r o v i d e a n o t h e r method by wh i c h t o e v a l u a t e p h a l l i c r e l a t i o n s h i p s . The i n t e r -i s l a n d samples are ranked i n the degree of d i v e r g e n c e i n baculum and d i s t a l t r a c t l e n g t h s . The d i v e r g e n c e v a l u e s are o b t a i n e d by t a l l y i n g the number of a l t e r n a t i v e i s l a n d samples t h a t are s i g n i f i c a n t l y d i f f e r e n t a t the 5 p e r c e n t l e v e l i n the baculum and d i s t a l t r a c t mean v a l u e s . For example i f sample A i s s i g n i f i c a n t l y d i f f e r e n t i n baculum l e n g t h from samples B, C, and i n d i s t a l t r a c t l e n g t h from samples x and z then sample A would have a d i v e r g e n c e v a l u e of 4. The p h a l l i of the s m a l l mice are the most d i v e r g e n t and, c o n v e r s e l y , the p h a l l i of l a r g e mouse phenotypes are somewhat l e s s v a r i a b l e i n morphology. The h y b r i d o f f s p r i n g are t r u l y i n t e r m e d i a t e i n p h a l l i c measurements. There i s , however, no break i n the c l i n e o f d i v e r g e n c e v a l u e s t h a t d i f f e r e n t i a t e the s m a l l from the l a r g e phenotypes. The h y b r i d p h a l l u s appears to be a b l e n d i n g of a l l c h a r a c t e r s found among the t e n i s l a n d samples. T h i s i s perhaps i n d i c a t i v e of a c l o s e p h y l o g e n e t i c r e l a t i o n s h i p e x i s t i n g w i t h i n t h i s group o f r o d e n t s . Hence t h i s study demonstrates t h a t e x t e n s i v e v a r i a t i o n i n p h a l l i c morphology e x i s t s among the i s l a n d Peromyscus. I f the c r i t e r i a e s t a b l i s h e d by Hooper were to be a p p l i e d i n t h i s s i t u a t i o n each of the i n s u l a r p o p u l a t i o n s would be d e s i g n a t e d a f u l l s p e c i e s . The c l i n e i n some of the c h a r a c t e r i s t i c s tends to r e f u t e p h a l l i c taxonomy as b e i n g a p p l i c a b l e t o t h i s s i t u a t i o n . No d i s t i n c t groups can be d i f f e r e n t i a t e d and no c o r r e l a t i o n between p h a l l i c c h a r a c t e r s and morphology are apparent e x c e p t , as n o t e d , where the c l i n e s i n p h a l l i c c h a r a c t e r s are p o l a r i z e d between the l a r g e and s m a l l mouse phenotypes. DIVERGENCE ISLAND SAMPLE SIZE VALUE Hope and V a n s i t t a r t 30 19 Thormanby and Texada 17 17 B a l a c l a v a 8 16 Cox - 7 14 Doyle 9 13 N i g e i and T r i a n g l e 16 12 Lanz 6 11 H y b r i d ( T r i a n g l e / C o x ) 3 5 Table 13 Divergence between i s l a n d samples u t i l i z i n g the combined baculum and d i s t a l t r a c t l e n g t h measurements. KARYOTYPIC VARIATION IN INSULAR PEROMYSCUS K a r y o l o g y can be i n s t r u m e n t a l i n the a n a l y s i s of many taxonomic problems. T h i s t e c h n i q u e i s , however, o n l y one of many c h a r a c t e r s t o be c o n s i d e r e d i n the o v e r a l l taxonomic e v a l u a t i o n of any group. To make a g e n e r a l i z a t i o n , such as t h a t made by O r l o v (1970), t h a t f i v e m u t a t i o n s i n chromosome s t r u c t u r e i s s i g n i f i c a n t i n s p e c i e s d i f f e r e n t i a t i o n i s i n my o p i n i o n u n j u s t i f i a b l e . I n the non - R o b e r t s o n i a n system of chromosome e v o l u t i o n t h a t o c c u r s i n a l l Peromyscus, one mu t a t i o n can t h e o r e t i c a l l y p r e s e n t major problems to the m e i o t i c p r o c e s s . An example of the uses of k a r y o l o g y i s the a n a l y s i s of the Peromyscus oreas complex which i s composed of two d i s t i n c t k a r y o t y p e groups (N. Bradshaw, p e r s o n a l communication). The c o a s t a l P. oreas are k a r y o t y p i c a l l y i d e n t i c a l t o the P. mani-c u l a t u s , h a v i n g a low number of somatic chromosome arms (F.N.), y e t are supposedly m o r p h o l o g i c a l l y and b e h a v i o r a l l y d i s t i n c t i v e . The second oreas group, found i n l a n d , i s a member of the h i g h F.N. s e r i e s and i s perhaps c l o s e l y r e l a t e d to the l a r g e morph i n s u l a r r a c e s t h a t have been c h a r a c t e r i z e d i n t h i s study. The study r e s p o n s i b l e f o r the e l e v a t i o n of oreas t o f u l l s p e c i e s (Sheppe, 1961) has a p p a r e n t l y not gone f a r enough, s i n c e the m o r p h o l o g i c a l and b e h a v i o r a l v a r i a t i o n does not r e f l e c t the k a r y o t y p i c s i t u a t i o n . L a w l o r (1971) has shown c o n s i d e r a b l e k a r y o t y p i c v a r i a t i o n among the Peromyscus i n h a b i t i n g the i s l a n d s of the G u l f of C a l i f o r n i a . These v a r i a t i o n s . a r e s p e c i e s s p e c i f i c and l i t t l e i n f o r m a t i o n r e g a r d i n g s u b s p e c i f i c and i n t r a p o p u l a t i o n v a r i a -t i o n i s r e c o r d e d . My study seeks t o answer the f o l l o w i n g t h r e e q u e s t i o n s u s i n g a l l o p a t r i c p o p u l a t i o n s of a p p a r e n t l y c l o s e l y r e l a t e d Peromyscus. 1) What i s the e x t e n t of k a r y o t y p e v a r i a t i o n t h a t e x i s t s w i t h i n these i n s u l a r p o p u l a t i o n s of Peromyscus and what elements are the most f r e q u e n t l y i n v o l v e d i n the e v o l u t i o n of the k a r y o t y p e ? 2) Can the k a r y o t y p e be c o r r e l a t e d w i t h or be i n s t r u m e n t a l i n d e t e r m i n i n g the s p e c i e s and s u b - s p e c i e s r e l a t i o n s h i p s ? That i s to say, can s t a s i p a t r i c s p e c i a t i o n account f o r the i n t e r i s l a n d v a r i a t i o n ? 3) Can d a t a from i s l a n d groups, such as those s t u d i e d , p r o -v i d e f u r t h e r i n s i g h t i n t o the r e l a t i o n s h i p s of c o n t i n e n t a l p o p u l a t i o n s ? Such c h a l l e n g i n g q u e s t i o n s as the p o s s i b i l i t y of i n t r a -i s l a n d deme r e l a t i o n s h i p s and the p o p u l a t i o n d e n s i t y - g e n e t i c r e l a t i o n s h i p s cannot as y e t be a s c e r t a i n e d . To undertake such a study would r e q u i r e e x t e n s i v e study upon each i s l a n d . My hope of f i n d i n g a g e n e t i c pathway l e f t by e m i g r a t i n g f o u n d i n g s t o c k s has been abandoned. The c o m p l e x i t y of the c o a s t l i n e , the a l l o p a t r i c n a t u r e of the Peromyscus, and the number of i s l a n d t r a i l s l e a v e s such a study t o the realm of team i n v e s t i g a t i o n on a l o n g term b a s i s . MATERIALS AND METHODS A l l Peromyscus (n=326) were t r a p p e d u s i n g 8\" Sherman l i v e t r a p s and r e t u r n e d to the l a b o r a t o r y a l i v e f o r a n a l y s i s . K a r y o t y p e s were o b t a i n e d from bone marrow c e l l s and from t i s s u e c u l t u r e s of ear e p i d e r m a l c e l l s . The bone marrow method n e c e s s i t a t e s the s a c r i f i c e of the specimen but i n t u r n i s f a s t e r and i s of equal or b e t t e r q u a l i t y than the t i s s u e c u l t u r e t e c h n i q u e . However, b r e e d i n g s t u d i e s r e q u i r e d the use of the ear c u l t u r e t e c h n i q u e so t h a t the a n i m a l s of known k a r y o t y p e s c o u l d be s e l e c t e d f o r mating c r o s s e s a t a l a t e r d a t e . Bone marrow method. T h i s i s a m o d i f i e d v e r s i o n of the F o r d and Hamerton (1956) C o l c h i c i n e - h y p o t o n i c c i t r a t e t e c h n i q u e . \" V e l b e , \" E l i L i l l y and Co., was s u b s t i t u t e d f o r the c o l c h i c i n e . I n t e r -p e r i t o n e a l i n j e c t i o n s of a 0.125% Velbe s o l u t i o n , 0.01 ml/g body w e i g h t , were made one hour b e f o r e the animal was t o be s a c r i f i c e d . The bone marrow c e l l s were f l u s h e d out and a s p i r a t e d i n - the manner o u t l i n e d by Hsu and P a t t o n ( B e n i r s h k e , 1969). Then the c e l l s u s p e n s i o n was i n c u b a t e d f o r e i g h t minutes i n a water b a t h a t 38° F. F a i l u r e t o i n c u b a t e i n the water b a t h r e s u l t e d i n inadequate c e l l u l a r s w e l l i n g and l a c k of metaphaseplates. I n t h i s r e s p e c t the n o r t h e r n Peromyscus seem t o possess a c e l l l i n e more r e s i s t a n t t o the s t a n d a r d procedures than does the s o u t h e r n c o n t i n e n t a l Peromyscus fauna. Such r e s i s t a n c e to the t e c h n i q u e o c c u r r e d i n l a b o r a t o r y p o p u l a t i o n s of P. m a n i c u l a t u s s o n o r i e n s i s a f t e r t h e y had been m a i n t a i n e d on a l a b o r a t o r y d i e t f o r s e v e r a l months (Thomas, 1968). No such change was noted i n the i s l a n d c a p t i v e s t o c k s m a i n t a i n e d i n the l a b o r a t o r y f o r over two y e a r s . Bone marrow c e l l s t a k e n from b o t h the o l d , l a b o r a t o r y r a i s e d animals and from the newly caught mice r e q u i r e d the warm b a t h t r e a t m e n t . I b e l i e v e t h a t t h i s c o n d i t i o n i s a f u n c t i o n of the metabolism and t h a t the d i e t a f f e c t s the osmotic and o t h e r p h y s i c a l p r o p e r t i e s of the c e l l . T i s s u e c u l t u r e method. The' b a s i c t e c h n i q u e f o r t h i s p r o c e s s has been o u t l i n e d by Hsu (Hsu, 1969). A m o d i f i e d v e r s i o n of t h e Hsu t e c h n i q u e was u t i l i z e d i n t h i s study i n o r d e r t o t a k e advantage of the f a c i l i t i e s made a v a i l a b l e to me by the Canadian Cancer S o c i e t y and the L a b o r a t o r y of Dr. H. S t i c h . A b r i e f o u t l i n e of the m o d i f i e d procedure i s as f o l l o w s ; 1) Wash the l e f t ear of the a n i m a l w i t h 10% a l c o h o l p r i o r t o 2 removing a 10-15 mm t e r m i n a l p o r t i o n of the organ. 2) Cut the ear t i s s u e i n t o s m a l l fragments and suspend i t i n 4 ml. of 0.25$ T r y p s i n f o r 1 hour. 3) Decant the t r y p s i n and wash the ear fragments i n 2 ml. of growth media. C e n t r i f u g e the sample f o r 5 minutes a t 800 r.p.m. Decant the wash s o l u t i o n . 4) Resuspend the ear fragments i n 4 ml. of f r e s h media and u s i n g a P a s t e u r p i p e t t e p l a c e 1 ml. i n t o each of 4 L e i g h t o n c u l t u r e tubes c o n t a i n i n g p r e c l e a n e d c o v e r s l i p s . 5) C u l t u r e i n an i n c u b a t o r s e t a t 36 C. changing the media every o t h e r day. 6) I n 7-10 days a monolayer of c e l l s s h o u l d form over the cover s l i p . A t t h i s time remove the c o v e r s l i p and submerse i n a h y p o t o n i c s o l u t i o n of one p a r t growth media and t h r e e p a r t s d i s t i l l e d water. 7) A f t e r 8 minutes of p r e t r e a t m e n t remove the c o v e r s l i p and, a f t e r d r a i n i n g , p l a c e i t g e n t l y i n Carnoy's f i x a t i v e . Remove the c o v e r s l i p a f t e r 10 minutes and a l l o w t o d r y t h o r o u g h l y . 8) . S t a i n f o r 6 minutes u s i n g Aceto O r c e i n s t a i n . 9) C l e a r the c o v e r s l i p w i t h a b s o l u t e a l c o h o l baths b e f o r e mounting upon the s l i d e . CLASSIFICATION ARM RATIO NOTES METACENTRIC 4/8-5/8 biarmed SUBMETACENTRIC (SM) 5/8-6/8 biarmed SUBTELOCENTRIC (ST) 6/8-7/8 problem group TELOCENTRIC OR ACROCENTRIC 7/8-8/8 no v i s i b l e arms (A or T) \" r a b b i t e a r s \" m e t a c e n t r i c s u b t e l o c e n t r i c a c r o c e n t r i c (problem group) Table 14 Nomenclature f o r chromosome t y p e s . RESULTS AND DISCUSSION W i t h i n the i s l a n d sample t h e r e e x i s t two d i s t i n c t k a r y o -type groups. The sample from the s o u t h e r n i s l a n d s of the Ge o r g i a S t r a i t group have a low number of biarmed chromosomes and c o n s e q u e n t l y a low fundamental number. The sample from the n o r t h e r n S c o t t I s l a n d s have a h i g h number of biarmed chromosomes and a c o r r e s p o n d i n g l y h i g h fundamental number. The fundamental number (F.N.) i s the number of chromosomal arms possessed by the somatic chromosome complement. The i n t e r m e d i a t e i s l a n d group, the Gordon and G o l e t a s i s l a n d s , are r e p r e s e n t e d by i n t e r m e d i a t e k a r y o t y p e s , i n d i c a t i v e perhaps of a complex g e n e t i c h e r i t a g e . The d a t a p r e s e n t e d ( t a b l e 16) show t h a t some k a r y o t y p i c v a r i a t i o n e x i s t s w i t h i n the s o u t h e r n group even though these mice are so s i m i l a r p h e n o t y p i c a l l y t h a t they are c o n s i d e r e d one s u b s p e c i e s ( H a l l , 1938). The major d i f f e r e n c e occurs i n the Texada p o p u l a t i o n where a r e d u c t i o n i n the number of biarmed chromosomes has taken p l a c e . One p a i r of biarmed chromosomes i n the s m a l l s i z e c a t e g o r y has undergone a p e r i -c e n t r i c i n v e r s i o n f o r m i n g an a c r o c e n t r i c chromosome p a i r . T h i s k a r y o t y p e was expressed i n 74 per cent of the sample. I n the r e m a i n i n g 26 per cent the k a r y o t y p e , t y p i c a l of the P. m. g e o r g i e n s i s i n h a b i t i n g the o t h e r i s l a n d s , was expressed. The gonosomes a r e a l s o s i t e s of chromosome polymorphism w i t h i n t h i s s u b s p e c i e s . Savary I s l a n d possesses two Y chromosome t y p e s . Three of the f i v e a n i m a l s k a r y o t y p e d ISLAND NUMBER OF NUMBER OF ISLAND GROUP CELLS ANIMALS COUNTED EXAMINED BOWEN 14 4 THORMANBY 44 12 TEXADA 54 13 SAVARY 19 5 DOYLE 5 3 HURST 4 1 BALACLAVA 5 2 NIGEI 81 18 VANSITTART 68 13 HOPE 85 20 COX 13 6 LANZ 20 5 TRIANGLE 44 9 T o t a l 464 112 Table 15 C o l l e c t i o n . and s ka r y o t y p e s tudy. G e o r g i a S t r a i t s group Gordon and G o l e t a s group S c o t t I s l a n d group iple s i z e d a t a f o r the ISLAND CHROMOSOME . SOMATIC CHROMOSOMES F.N. NUMBER BIARMED ACROCENTRIC A* B* BOWEN 48 28 0 18 74 THORMANBY 48 28 0 18 74 TEXADA 48 26 0 20 72 SAVARY 48 28 0 18 74 DOYLE 48 36 4 6 86 HURST 48 32 0 14 78 BALACLAVA 48 30 0 1 6 76 NIGEI 48 32 6-8 8-6 84-86 VANSITTART 48 24 4 18 74 HOPE 48 28 0 18 74 COX 48 36 4 6 86 LANZ 48 36 4 6 86 TRIANGLE . 48 36 4 6 86 P.m.austerus 48 28 _ 18 74 P.oreas (coas t ) 48 28 — 18 74 P . s i t k e n s i s 48 40 - 6 86 A* s u b m e t a c e n t r i c s B* s u b t e l o c e n t r i c s , s u b j e c t t o m i s i d e n t i f i c a t i o n . Table 16 Karyotype c h a r a c t e r i s t i c s f o r the Peromyscus of the B.C. r e g i o n . P. s i t k e n s i s (20) S c o t t I s . (20) P. oreas (13) P. m. r u b i d u s \" 0 3,14,15) See i n s e t map P. oreas (14) . m. g e o r g i e n s i s 7 j 3 and 14) P. oreas (18 and 20) P.m. a u s t e r u s (14) P. m. gambeli I 13,14,15,16,17) Hope (14) Vans i t t a r t (14) N i g e i (20) k 5 A K B a l a c l a v a (15) s t 6') Doyle °.. (20) W ). Hur F i g . 15 Somatic m e t a c e n t r i c chromosome numbers f o r some west c o a s t p o p u l a t i o n s of Peromyscus. e x h i b i t e d a Y chromosome t y p i c a l of the Texada and Thormamby p o p u l a t i o n s , a s m a l l a c r o c e n t r i c , w h i l e the o t h e r two s p e c i -mens were i d e n t i c a l to the Bowen type i n h a v i n g a s m a l l sub-t e l o c e n t r i c Y chromosome. T h i s polymorphic c o n d i t i o n can h a r d l y be c o n s i d e r e d t o be due t o t h e i n f l u e n c e of a d j a c e n t mainland p o p u l a t i o n s . P. m. a u s t e r u s of the S e c h e l t P e n i n s u l a r e g i o n of B r i t i s h Columbia, 50 m i l e s n o r t h of Vancouver, has a l a r g e s u b t e l o c e n t r i c chromosome (Thomas, 1970). The P. oreas p o p u l a t i o n s are a l s o t o be d i s c o u n t e d f o r b r i n g i n g about t h i s polymorphism f o r they, t o o , have a Y chromosome t h a t i s u n l i k e e i t h e r of the two found i n the Savary 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 the complex c o a s t l i n e of B r i t i s h Columbia, h a r b o r s numerous k a r y o t y p i c l i n e s of Peromyscus not y e t r e c o g n i z e d as d i f f e r e n t and most l i k e l y not even seen by a t a x o n o m i s t . The i s l a n d p o p u l a t i o n s c o u l d have been t h e r e s u l t of f o u n d i n g c o l o n i e s t h a t are k a r y o l o g i c a l l y v a r i e d y e t from the same g e n e r a l a r e a . I t i s p o s s i b l e , f o r example, t h a t Savary I s l a n d was invaded by two such r a c e s and the r e m a i n i n g i s l a n d s i n the group were invaded by one or the o t h e r but not both. A f u r t h e r c o m p l i c a t i o n of the k a r y o t y p i c a n a l y s i s a rose when I found t h a t i n some animals v a r i a t i o n i n the k a r y o t y p e o c c u r r e d w i t h i n the same t i s s u e c e l l l i n e . The o c c u r r e n c e of c e l l u l a r mosaicism i s f u r t h e r c o m p l i c a t e d by a n o t i c e a b l e f r e q u e n c y of heteromorphic chromosome p a i r i n g . The most s e r i o u s problem i n the a n a l y s i s a rose from the d i s c o v e r y t h a t s i g n i f i c a n t v a r i a t i o n i n the b i a r m e d / a c r o c e n t r i c r a t i o s e x i s t i n every sample. I n t e r c e l l u l a r and i n d i v i d u a l k a r y o -t y p i c v a r i a t i o n has been noted i n o t h e r Peromyscus p o p u l a -t i o n s (Ohno et a l , 1966; A r a k a k i and Sparkes, 1966) y e t i t i s o n l y i n the work of K r e i z i n g e r and Shaw (1970) t h a t any i n d i c a t i o n of the e x t e n t of the polymorphisms i n Peromyscus i s brought t o l i g h t . K r e i z i n g e r found one specimen of P. m. r u f i n u s w i t h t h r e e d i f f e r e n t k a r y o t y p e s . The v a r i a t i o n i n t h i s case was due t o the mis-matching of one or two chromosome p a i r s . The v a r i a t i o n noted i n my study i s of a much g r e a t e r magnitude and n e c e s s i t a t e s the f o l l o w i n g s t a t i s t i c a l maneuver i n o r d e r to a l l e v i a t e the problem. A l l r a t i o s f o r these i s l a n d Peromyscus are based upon the modal average r a t i o of biarmed to a c r o c e n t r i c chromosomes found i n the p o p u l a t i o n sampled. The d i s c r e p a n c i e s i n the k a r y o t y p e a r i s e from the d u a l phenotype of one p a r t i c u l a r group of chromosomes. These chromosomes (group B, t a b l e 32) appear as both biarmed and as a c r o c e n t r i c t y p e s , depending upon the time a t which the DNA r e p l i c a t i o n c y c l e was a r r e s t e d . The s u b t e l o c e n t r i c chromosomes are a p p a r e n t l y time s e n s i t i v e t o the m i t o t i c a r r e s t i n g agent and the \" r a b b i t e a r s \" ( t a b l e 14) undergo d r a s t i c c o n t r a c t i o n s . Consequently, o p t i c a l a n a l y s i s of gross chromosome morphology i s rendered d i f f i c u l t and r e s u l t s i n the mis i d e n t i f i c a t i o n of many of these extreme s u b t e l o -c e n t r i c p a i r s of chromosomes. N i g e i I s l a n d has 8 p a i r s of these s u b t e l o c e n t r i c chromosomes and the modal average of the morphotype r a t i o s i s i n d e c i s i v e , the r a t i o s 38-8 and 40-6 occur w i t h equal frequ ency. The s u b t e l o c e n t r i c chromosomes (group B, t a b l e 32 and f i g . 2 9 ) , are s p e c i f i c t o the l a r g e mouse phenotype of t h i s study a r e a . However, P. s i t k e n s i s , a l a r g e mouse v e r y c l o s e l y a l l i e d i n h a b i t a t and s i z e to those of the S c o t t i s l a n d s , a p p a r e n t l y does not have t h i s group of B chromosomes (Hsu, 1970). The b i a r m e d / a c r o c e n t r i c r a t i o f o r P. s i t k e n s i s i s 40:6 and t h i s i s the same as the s i m i l a r morph s t u d i e d upon the S c o t t and G o l e t a s i s l a n d s ( t a b l e 16 and appendix 5 ) . I b e l i e v e t h a t t h i s s i m i l a r i t y may have taxonomic s i g n i f i c a n c e worthy of f u r t h e r i n v e s t i g a t i o n . I t seems t h a t a k a r y o t y p e / morphotype r e l a t i o n s h i p c o u l d be i n f e r r e d f o r these n o r t h e r n Peromyscus s i n c e the h i g h P.N. v a l u e s c o r r e s p o n d t o the l a r g e morphotype and v i c e v e r s a . This i s not the case f o r some of the c o n t i n e n t a l forms. Peromyscus c a l i f o r n i c u s , one of the l a r g e s t phenotypes i n the genus Peromyscus, has 19 p a i r s of a c r o c e n t r i c chromosomes (Thomas, 1968). T h i s r e p r e s e n t s a near r e v e r s a l of the chromosome morphotypes found i n the B r i t i s h Columbia p o p u l a t i o n s . C e l l u l a r mosaicism, i n the form of heteromorphic chromo-some p a i r i n g , i n c r e a s e s w i t h the i n c r e a s e i n F.N. v a l u e . The S c o t t I s l a n d Peromyscus [F.N.-86 ( t a b l e 16 and appendix 5)] had a f r e q u e n c y of mismatched* chromosomes a p p r o a c h i n g 12 per cent of the sample. The low F.N. groups tend t o be more c o n s t a n t l y s t a b l e k a r y o l o g i c a l l y . Can i t be t h a t the biarmed chromosome i s the more u n s t a b l e c o n f i g u r a t i o n and i s under-g o i n g f r e q u e n t i n v e r s i o n s ? I f t h i s i s the case, then i t would i n f e r t h a t the h i g h fundamental number group i s the most r e c e n t form of Peromyscus t o have e v o l v e d w i t h i n t h i s i s l a n d complex. T h i s i s not c o n s i s t e n t w i t h the g l a c i a l r e f u g i a t h e o r i e s put f o r t h by McCabe and Cowan (1945) and F o s t e r (1965). I n b o t h of the s e s t u d i e s P. s i t k e n s i s , a member of the h i g h F.N. group, i s a r e f u g i a l r e l i c t h a v i n g s u r v i v e d the Vashon g l a c i a t i o n i n the nunataks of the Queen C h a r l o t t e I s l a n d s . The k a r y o l o g i c a l evidence suggests t h a t T r i a n g l e , Cox, Lanz, N i g e i and Doyle Peromyscus s h o u l d be c o n s i d e r e d one c o h o r t , d i s t i n c t from the r e m a i n i n g i s l a n d s t h a t I have s t u d i e d . The r e m a i n i n g i s l a n d s are g e o g r a p h i c a l l y widespread. Hope, V a n s i t t a r t , B a l a c l a v a and H u r s t are a p p r o x i m a t e l y 170 m i l e s n o r t h of the G e o r g i a S t r a i t i s l a n d group, y e t P e r o -myscus from b o t h s e t s of i s l a n d s a re c h a r a c t e r i z e d by a low fundamental number ( t a b l e 16). B a l a c l a v a and H u r s t I s l a n d p o p u l a t i o n s of Peromyscus have undergone some e v o l u t i o n i n k a r y o t y p e ; perhaps due t o g e n e t i c i m m i g r a t i o n of the h i g h F.N. s t o c k . T h i s lat t e r p o i n t i s not s u b s t a n t i a t e d by the b r e e d i n g s t u d i e s , f o r i t was found t h a t the two k a r y o l o g i c a l s t o c k s (F.N.=86 and F.N.=74) do not i n t e r b r e e d i n the l a b o r a t o r y . Consequently any i n f l u x of the a l t e r n a t i v e gene p o o l would not i n f l u e n c e the r e s i d e n t p o p u l a t i o n . T h i s l e a v e s me w i t h o n l y one a l t e r n a t i v e , t h a t m u t a t i o n of the a n c e s t r a l forms has t a k e n p l a c e upon B a l a c l a v a and H u r s t I s l a n d s , and t h a t they are b oth i n c i p i e n t s p e c i e s . R e l y i n g upon these k a r y o l o g i c a l d a t a the T r i a n g l e , Cox, Lanz, N i g e i and Doyle I s l a n d Peromyscus s h o u l d be c o n s i d e r e d c l o s e l y r e l a t e d t o and i n a c o h o r t w i t h Peromyscus s i t k e n s i s , whereas the Hope, V a n s i t t a r t , B a l a c l a v a , H u r s t , Texada, Savary, Thormanby and Bowen I s l a n d Peromyscus s h o u l d be grouped w i t h Peromyscus m a n i c u l a t u s . I t would appear t h a t these two c o h o r t s would be m u t u a l l y i n c o m p a t i b l e g e n e t i c a l l y , s i n c e the m e i o t i c problems would seem to be i n s u r m o u n t a b l e , i n d i c a t i n g t h a t s t a s i p a t r i c s p e c i a t i o n has t h e r e f o r e t a k e n p l a c e . N a d l e r (1968) i n h i s study of the k a r y o t y p e s of Spermophilus townsendi has d i f f e r -e n t i a t e d a l l o p a t r i c p o p u l a t i o n s i n t o s p e c i e s groups based s o l e l y on v a r i a t i o n of chromosome numbers. As p r e v i o u s l y noted i t i s p r o b a b l y e a s i e r f o r m e i o s i s t o proceed under a R o b e r t s o n i a n than a n o n - R o b e r t s o n i a n system of chromosome e v o l u t i o n , and t h e r e f o r e the v a r i a t i o n i n the i s l a n d samples i s i n d i c a t i v e of a v e r y p l a s t i c a n i mal group t h a t i s e v o l v i n g r a p i d l y . CONCLUSIONS: A SYSTEMATIC REVIEW OF SOME INSULAR PEROMYSCUS Th i s study has shown t h a t t h e r e are two d i s t i n c t s p e c i e s of Peromyscus i n h a b i t i n g the o u t e r i s l a n d s a l o n g the B r i t i s h Columbia c o a s t . The p r e f e r r e d h a b i t a t f o r i n s u l a r Peromyscus i s the d r y , s t o n y beaches and the a d j a c e n t f o r e s t edge. These mice are l i t t o r a l s c a vengers, s u b s i s t i n g upon, or a t l e a s t r e l y i n g h e a v i l y upon, beach amphipods and i n s e c t l a r v a e . D u r i n g the summer months t h e r e i s v e r y l i t t l e d i e t a r y i n t a k e of v e g e t a b l e m a t e r i a l . No i s l a n d - s p e c i f i c h a b i t a t or d i e t a r y c h a r a c t e r i s t i c can be found to c o r r e l a t e w i t h the s p e c i e s or s u b s p e c i e s d e s i g n a t i o n s . E c o l o g i c a l and e t h o l o g i c a l p e c u l i a r i t i e s draw a t t e n t i o n to the T r i a n g l e I s l a n d p o p u l a t i o n of Peromyscus. The l a r g e s i z e , a m i c a b i l i t y , and s e m i - f o s s o r i a l way of l i f e are a t y p i c a l f o r c o a s t a l m a n i c u l a t u s . T a x o n o m i c a l l y the s e m i - f o s s o r i a l mode c o u l d be i m p o r t a n t but i n t e r - i s l a n d b r e e d i n g s t u d i e s have shown t h a t t h i s c h a r a c t e r i s t i c i s not i n h e r i t e d as a dominant t r a i t and I am of the o p i n i o n t h a t i t i s the l a c k of a l t e r n a t i v e h a b i t a t t h a t b r i n g s t h i s way of l i f e and i s a l e a r n i n g b e h a v i o u r and not a t r u e e v o l u t i o n a r y a d a p t a t i o n . E x t e n s i v e m o r p h o l o g i c a l v a r i a t i o n e x i s t s between some i s l a n d p o p u l a t i o n s . D i s c r i m i n a n t a n a l y s i s of the c r a n i a l and o t h e r m o r p h o l o g i c a l d a t a d i f f e r e n t i a t e s two n e a r l y e x c l u -s i v e groups w i t h i n the Peromyscus samples. B r e e d i n g s t u d i e s and mate s e l e c t i o n c h o i c e s s u b s t a n t i a t e ISLAND T r i a n g l e CURRENT NOMENCLATURE Peromyscus m a n i c u l a t u s t r i a n g u l a r i s PROPOSED REVISION Peromyscus s i t k e n s i s i s o l a t u s Lanz c a r l i i s o l a t u s Cox c a r l i i s o l a t u s N i g e i i s o l a t u s i s o l a t u s Doyle d o y l e i d o y l e i H u r s t saxamans saxamans Hope Peromyscus m a n i c u l a t u s b a l a c l a v a Peromyscus m a n i c u l a t u s e e o r f f i e n s i s * Vans i t t a r t N.A. g e o r g i e n s i s * B a l a c l a v a b a l a c l a v a b a l a c l a v a Texada g e o r g i e n s i s g e o r g i e n s i s Thormanby g e o r g i e n s i s g e o r g i e n s i s Savary g e o r g i e n s i s g e o r g i e n s i s Bowen g e o r g i e n s i s g e o r g i e n s i s * s u b j e c t t o comparison w i t h P. m. a u s t e r u s and P. m. i n t e r d i c t u s s u b s p e c i es Table 17 Proposed r e v i s i o n of the s y s t e m a t i c s of some i s l a n d Peromyscus. the e x i s t e n c e of the two c o h o r t s . The l a r g e and s m a l l pheno-type groups, c o h o r t s A and B ( t a b l e 1 7 ) , show d i s t i n c t p r e f e r -ence f o r the companionship of a s i m i l a r morph p a r t n e r . The h y b r i d l i t t e r s were the r e s u l t of l i k e morph c r o s s e s . M o r p h o l o g i c a l a f f i n i t i e s a re s t r o n g w i t h i n each c o h o r t w i t h the e x c e p t i o n of the V a n s i t t a r t and Doyle p o p u l a t i o n s . These two p o p u l a t i o n s are i n b oth cases d i s t i n c t . E x t e n s i v e p h a l l i c v a r i a t i o n e x i s t s w i t h i n and between i s l a n d p o p u l a t i o n s . The B a l a c l a v a Peromyscus are a t y p i c a l and unique i n h a v i n g a p h a l l u s of u n i f o r m t h i c k n e s s a l o n g i t s t o t a l g l a n d u l a r l e n g t h . The Doyle sample i s unique i n h a v i n g a l l v e n t r a l l a p p e t s c l e f t m e d i a l l y . The p h a l l i c v a r i a t i o n w i t h i n t h e samples p r e c l u d e s any d i f f e r e n t i a t i o n of the i s l a n d p o p u l a t i o n s i n t o any b i o l o g i c a l groups. 4 Karyotaxonomy f u r t h e r enhances the two group t h e o r y . The l a r g e morph has a d i s t i n c t k a r y o t y p e u n l i k e t h a t of any c o a s t a l P. oreas or P. m a n i c u l a t u s ( f i g . 15), but i t i s the same as t h a t possessed by the m o r p h o l o g i c a l l y s i m i l a r s p e c i e s , P. s i t -k e n s i s . The s m a l l morph i s k a r y o t y p i c a l l y a l l i e d t o t h e main-l a n d c o a s t a l P. m a n i c u l a t u s . Cowan (1935) c l a s s i f i e d the l a r g e morphotype as Peromyscus s i t k e n s i s i s o l a t u s and subse-q u e n t l y changed i t to P. m a n i c u l a t u s i s o l a t u s (McCabe and Cowan, 1945). I t i s my o p i n i o n t h a t the f i r s t c l a s s i f i c a t i o n i s more r e p r e s e n t a t i v e of the l a r g e morph group and t h a t a taxonomic r e v i s i o n of these i s l a n d Peromyscus i s n e c e s s a r y . Peromyscus s i t k e n s i s i s p h e n o t y p i c a l l y s i m i l a r to the l a r g e morph group. Peromyscus s i t k e n s i s i s a l s o i d e n t i c a l i n k a r y o -type to t h a t found i n the l a r g e morph c o h o r t . G e o g r a p h i c a l l y , P. s i t k e n s i s i s found upon i s l a n d s t o t h e n o r t h of the study groups. L a n d s l i d e s o r i g i n a t i n g i n the n o r t h e r n r e g i o n would stand an e x c e l l e n t chance of d e p o s i t i n g f o u n d i n g c o l o n i e s upon the study i s l a n d s . C o a s t a l P. o r e a s , a l t h o u g h pheno-t y p i c a l l y s i m i l a r t o the l a r g e morph group, i s k a r y o l o g i c a l l y i d e n t i c a l t o the c o a s t a l P. m a n i c u l a t u s . The map ( f i g . 9) demonstrates the d i s p e r s a l p a t t e r n s a l o n g the we s t e r n N o r t h American c o n t i n e n t . I propose t h a t the Peromyscus found upon T r i a n g l e , Lanz, Cox, N i g e i , Doyle, and H u r s t I s l a n d s s h o u l d be c o n s i d e r e d the s p e c i e s P. s i t k e n s i s , and t h a t the Peromyscus of Hope, Van-s i t t a r t , B a l a c l a v a , Savary, Texada, Thormanby, and Bowen remain as P. m a n i c u l a t u s . V a r i a t i o n e x i s t s w i t h i n each of the two c o h o r t s . The degree of v a r i a t i o n w i t h i n the c o n t i n e n t a l p o p u l a t i o n s of P. m. r u b i d u s and P. m. gam b e l i , t o g e t h e r w i t h the v a r i a t i o n t h a t e x i s t s between samples t a k e n one or two decades a p a r t , makes i t mandatory t h a t s u b s p e c i e s d e s i g n a t i o n s be made broad enough to encompass such n a t u r a l l y o c c u r r i n g m o r p h o l o g i c a l f l u c t u a t i o n s . S u b s p e c i f i c d e s i g n a t i o n s are somewhat a r b i t r a r y and are made w i t h the i n t e n t i o n of d i s t i n g u i s h i n g m o r p h o l o g i c a l l y s i m i l a r groups of animals t h a t are u s u a l l y g e o g r a p h i c a l l y d e f i n a b l e . The i n s u l a r s i t u a t i o n adds another d i m e n s i o n t o the problem of s u b s p e c i f i c nomenclature f o r i n t h i s case a l l p o p u l a t i o n s are a l l o p a t r i c and the chances of i n t e r b r e e d i n g are v i r t u a l l y n o n - e x i s t e n t . I s i t p r a c t i c a l t h e r e f o r e t o have s u b s p e c i f i c t i t l e s f o r i n s u l a r p o p u l a t i o n s ? I n my study the i n t e r - i s l a n d v a r i a t i o n i s i n some cases l e s s than the v a r i a t i o n found w i t h i n the i s l a n d sample, e s p e c i a l l y when the changes over a twenty-year p e r i o d are c o n s i d e r e d . These p o p u l a t i o n s s h o u l d be c o n s i d e r e d as con-s u b s p e c i f i c i n most cases. D i s t i n c t i v e m o r p h o l o g i c a l t r a i t s , such as i n the Doyle I s l a n d Peromyscus, s h o u l d be c o n s i d e r e d i n t he f i n a l e v a l u a t i o n . I have i n d i c a t e d i n t a b l e 17 the s u b s p e c i f i c t a x a t h a t are suggested by my study. However the a d j a c e n t mainland p o p u l a t i o n s (P. m. a u s t e r u s ) and the n o r t h e r n Vancouver I s l a n d Peromyscus (P. m. i n t e r d i c t u s ) , have not been c o n s i d e r e d i n the e v a l u a t i o n and t h e r e f o r e the s u b s p e c i f i c d e s i g n a t i o n s are to be c o n s i d e r e d as o n l y r e l a t i v e t o the i s l a n d sample u t i l -i z e d i n t h i s study. V a n s i t t a r t I s l a n d Peromyscus are i n a l l c h a r a c t e r i s t i c s v e r y s i m i l a r t o the g e o r g i e n s i s s u b s p e c i e s found 170 m i l e s t o t h e so u t h . T i d a l f l o w c o u l d have accounted f o r t h i s d i s t r i b u t i o n and i n or d e r t o convey the s i m i l a r i t i e s e x i s t i n g among the i s l a n d forms I c o n s i d e r t h a t the con-sub-s p e c i f i c t i t l e i s j u s t i f i e d . Doyle I s l a n d Peromyscus are m o r p h o l o g i c a l l y d i s t i n c t i v e ( f i g . 8 ) . Th i s i s l a n d form i s c h a r a c t e r i z e d by a l a r g e lambdoidal r i d g e , which i s unique among the i s l a n d Peromyscus, and cone shaped v e n t r a l l a p p e t s on the p h a l l u s . Together these c h a r a c t e r s e s t a b l i s h d o y l e i as a b i o l o g i c a l l y sound s u b s p e c i f i c t a x o n . H u r s t I s l a n d Peromyscus are c l o s e r t o Cox I s l a n d P e r o -myscus i n m o r p h o l o g i c a l dimensions ( f i g . 8) than to d o y l e i (Cowan and G u i g e t , 1965). D e s p i t e the s i m i l a r i t y to the o t h e r member of the c o h o r t A ( t a b l e 17, f i g . 8) I c o n s i d e r the k a r y o t y p i c v a r i a t i o n ( t a b l e 16) to be s i g n i f i c a n t enough to h i n d e r i n t e r - i s l a n d c r o s s e s . The f o u r chromosomal changes are a severe i m p o s i t i o n upon the m e i o t i c p r o c e s s e s of any h y b r i d s . I n t h i s i n s t a n c e I b e l i e v e s t a s t i p a t r i c s p e c i a t i o n has t a k e n p l a c e . The s m a l l morph c o h o r t i s m o r p h o l o g i c a l l y one form. The k a r y o t y p i c v a r i a t i o n s are minor and are encompassed w i t h i n the n a t u r a l v a r i a t i o n found w i t h i n the n e i g h b o r i n g p o p u l a t i o n s . The B a l a c l a v a I s l a n d v a r i a t i o n i s , however, s i g n i f i c a n t a t the s u b s p e c i f i c l e v e l . The k a r y o t y p e v a r i a t i o n ( t a b l e 16) and the t h i c k d i s t i n c t i v e p h a l l u s g i v e t h i s group a unique c h a r a c t e r among t h i s o t h e r w i s e mono-phenotype c o h o r t . Texada I s l a n d Peromyscus d i s p l a y an a t y p i c a l k a r y o t y p e i n t h a t they have o n l y 26 m e t a c e n t r i c chromosomes, but the o t h e r c h a r a c t e r s measured are s t i l l w e l l w i t h i n the range e x h i b i t e d by the o t h e r P. m. g e o r g i e n s i s . I t appears t h a t a t h r e s h o l d of s u b s p e c i a t i o n must be e s t a b l i s h e d a t such a l e v e l as t o a l l o w f o r n a t u r a l morphol-o g i c a l v a r i a t i o n . T h i s r e q u i r e s the r e c o g n i t i o n of broad t a x a . I n the case of the i n s u l a r Peromyscus i t appears t h a t c r a n i a l morphology, s p e c i f i c a l l y the l a m b d o i d a l r i d g e , the o v e r a l l p h a l l i c morphology (but not any one s p e c i f i c p h a l l i c f e a t u r e ) , and the k a r y o t y p e , are s e n s i t i v e a t the s u b s p e c i f i c l e v e l . The s p e c i e s s h o u l d be d e f i n e d by a n a l y s i s of gross c r a n i a l and o t h e r m o r p h o l o g i c a l measurements t a k e n from samples o b t a i n e d over many y e a r s , as v e i l as by c o n s i d e r a t i o n of the b r e e d i n g p r e f e r e n c e s of the a n i m a l s s t u d i e d . D i f f e r -e n t i a t i o n of i n s u l a r p o p u l a t i o n s of Peromyscus must be done w i t h the awareness t h a t n a t u r a l a n i m a l p o p u l a t i o n s are dynamic and c o n s t a n t l y changing e n t i t i e s . The i d e a of geo-g r a p h i c v e r n a c u l a r ( W i l s o n and Brown, 1953) b e i n g a p p l i e d to i n s u l a r p o p u l a t i o n s i s not s c i e n t i f i c a l l y a p p r o p r i a t e . Such a system of i s l a n d p o p u l a t i o n nomenclature i s o n l y \" p r e c i s e \" i n the d e s i g n a t i o n of the c o l l e c t i o n l o c a l i t y , i t does not convey any i d e a of the e v o l u t i o n a r y r e l a t i o n s h i p between any of the n e i g h b o r i n g r a c e s . I have found i n t h i s s t udy t h a t the S c o t t I s l a n d Peromyscus are d i s t i n c t from the G e o r g i a S t r a i t Peromyscus, a t what I c o n s i d e r t o be the s p e c i e s l e v e l , but w i t h i n the S c o t t group the Peromyscus are m o r p h o l o g i c a l l y and k a r y o t y p i c a l l y v e r y c l o s e . To d e s i g n a t e each of the S c o t t I s l a n d p o p u l a t i o n s as s e p a r a t e e n t i t i e s would convey n o t h i n g t o the t a x o n o m i s t and the n e c e s s a r y r e v i e w of the l i t e r a t u r e t o a s c e r t a i n any d e s c r i p t i o n would be a t e d i o u s t a s k r e m i n i s c e n t of the p r e - L i n n e a n e r a . The types of i n f o r m a t i o n I have u t i l i z e d i n t h i s s tudy l e a d me to the f o l l o w i n g r e v i s i o n as b e i n g the most meaningful e v a l u a t i o n of the Peromyscus on these i s l a n d s . Two s p e c i e s of Peromyscus can be found upon the i s l a n d s o f f the c o a s t of B r i t -i s h Columbia. Peromyscus s i t k e n s i s occurs on N i g e i , Doyle, H u r s t , T r i a n g l e , Cox, and Lanz I s l a n d s . The s m a l l e r morph, found on Hope, V a n s i t t a r t , B a l a c l a v a , and the G e o r g i a S t r a i t I s l a n d s , i s of the s p e c i e s Peromyscus m a n i c u l a t u s . The sub-s p e c i e s P. _s. i s o l a t u s i n h a b i t s T r i a n g l e , Cox, Lanz, and N i g e i I s l a n d s . Doyle I s l a n d Peromyscus, due t o a major d i f f -erence i n c r a n i a l morphology, must be c o n s i d e r e d a s e p a r a t e s u b s p e c i e s , P. s r. d o y l e i . H u r s t I s l a n d Peromyscus, a l t h o u g h p o s s e s s i n g no o s t e o l o g i c a l p e c u l i a r i t i e s , are p h e n o t y p i c a l l y and k a r y o t y p i c a l l y d i s t i n c t i v e ; thus t h e y are d e s e r v i n g of the s u b s p e c i f i c t a xon P. £. saxamans. Among the s m a l l morph group, P. m a n i c u l a t u s , so l i t t l e m o r p h o l o g i c a l and k a r y o l o g -i c a l v a r i a t i o n e x i s t s t h a t a l l p o p u l a t i o n s , except f o r those of B a l a c l a v a I s l a n d , s h o u l d be c o n s i d e r e d c o n - s u b s p e c i f i c . I have p l a c e d them as P. m. g e o r g i e n s i s , s u b j e c t t o comparison t o mainland P. m. a u s t e r u s and P. m. i n t e r d i c t u s from Vancouver I s l a n d . APPENDIX 1 MEASUREMENT DATA FOR INSULAR PEROMYSCUS MAXILLARY CM o CM O CM O 10 10 CM O r - l O CM o T00THR0W + l\" + 1 • + 1 * + 1 • + 1 + l\" +i + 1 • + 1 Ti- Th\" Th Ti- Th cn Th cn cn en cn cn en cn cn cn m cn cn cn cn cn cn cn cn cn cn POSTPALATAL O O O O • O O • O- O o • LENGTH + 1 + 1* + f + 1 + r + 1 + r + r + 1 00 oo 00 00 ON 00 m ON t-00 00 CO CO 00 00 00 00 00 cn cn Th cn CM cn CM cn CM DIASTEMA o O o O o O O o o • • • • • • WIDTH + ! Th +*! Th +\"l + 1 N 0 +\"l NO + 1 CM + 1 o + 1 cn + 1 r H NO vo vO NO vO vo vD cn cn cn cn CM cn cn Th cn PALATINE o O O O • o . o • o O • O FORAMEN -H o +*l ON +\"l o + 1 o -H O + i 00 +\"l t-+ 1 r H +\"l 00 i n Ti- i n m i n Tf Th i n Th cn en cn m CM CM Th cn cn O o o O O o O O o SHELF OF + \\ +] • + 1 +i +i +i +'\\ +i • + 1 BONY PALATE i n i n N£> t~ t> Tt- cn cn Th • cn cn cn cn cn cn cn cn cn i n m i n Th T)- i n i n Th LENGTH OF o O O O • O * o • O O • o NASALS + 1 00 +i oo + i + l ON + 1 r H + 1 i n +i i n + 1 i n + 1 i n ON ON O ON ON ON ON • • • • r H • • • * CM CM CM CM r H r H CM r H r H o o o o O O o O O INTERORBITAL + i + i + i + 1 * + 1 • + 1 + 1 + i + '\\ CONSTRICTION 00 i n NO NO i n m cn cn cn cn cn • cn • cn • cn « m cn cn cn TP r H O O O O O O O o O BREADTH + \"l - f ' l + i +i +i +i +i +i +i OF SKULL cn r H CM i—1 TI-i—i cn r H Th r H r H r H cn r H r H r H CM r H i—1 r H r H r H r H r H r H r H r H i n i n i n i n i n Th kO O O o O O o O O o BASILAR + 1 + 1 + 1 • + 1 * + 1 • + 1 + 1 tr! LENGTH r-t ON 00 r H ON cn ON cn ON 00 00 cn 00 ON 00 OO r H r H r H r H r H r H r H r H r H t~ c- OO i n h - oo VD t— O o O O O o o O o OCCIPITONASAL + l\" + \\ + 1* + r • + 1 • + 1 • +1 +' l + ' l LENGTH ON Th Tt- 00 Th CM i n cn i n m Th CM Th i n Th Th Th CM CM CM CM CM CM CM CM CM SAMPLE SIZE i n o i n r H O 00 00 PH r H 00 vO CO i n cn Th r H r H CM • o < o • O • PH o CO o Jz; co CxJ co I—i CO 1—1 w . O CO CO & r H r H < • • • < PQ PH

-P cu Pi e n3 0) r l rH ca T3 Pi ca ca -p e r H ca Pl •H o Pi ca + 1 u Oi M ca r t d) < f> r H ca PI CD ca r H a> S ca EH MAXILLARY TOOTHROW DIASTEMA WIDTH PALATINE FORAMEN SHELF OF BONY PALATE LENGTH OF NASALS INTERORBITAL CONSTRICTION BREADTH OF SKULL BASILAR LENGTH OCCIPITONASAL LENGTH SAMPLE SIZE + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + o CM i n i n i n > > > > > > > > > > o i—i i—i r H CM CM CM + + + + + + + + -p X CD -p Pi •H CD U ' Pi bo •H PH ci B PI o •H -P P) r& •H ?H -P co •H ^ CD 0 CO W W > t> H W m r-H EH EH EH EH ' r l I—I I—I & S W 02 ^J- pi cd + ri W ) + + + + + + + + SI PHI PI •H CO -p PI CD e CD rl PI CO d CD e PI o PI CD PI CD CD t* -P CD PI O •rl -P c6 • r H U (A > H H . O CD O PI ct? O •rl «H •H P! 60 •rl W CM EH CM rH rH rH CM CM rH CM MAXILLARY O o O O O o o O o TOOTHROW +1* + 1 + l' + 1 +1 +1* + f + f h i co vO i n CO CO * CO +o • co CO co • co co POSTPALATAL -si-O CO o LPi o CO o CO O CO o co o O . O LENGTH + 1 • + 1 • + 1 • + 1 + 1 * + 1 + i + 1 CM rH co rH o o rH O ON ON ON ON ON ON ON ON • • « » « « i n co CO CO CM DIASTEMA o o • O • o • o o O O o WIDTH +i +1 + 1 + 1 +'l +i +i + i +} t - vO 0 0 0 0 rH CO i n i n m vo • vO • vO • vO • • vO • • vO • vO • CO co co CM CO CM O O O O O o o o O PALATINE • • • • • • • • • + I + 1 + 1 + 1 + 1 + 1 +1 + 1 + 1 FORAMEN rH rH CM o CO ON o CO rH LfN. i n • i n i n • i n • xr i n i n i n CM CM CM rH rH ro CM co co SHELF OF O • o O • o « O • O • o O O BONY PALATE + 1 vO + f vO + 1 > vO + 1 vO + 1 i n + 1 vO + f i n + f + f VO CO CO • CO • CO • ro « ro • CO • co • co i n vO i n vO O o o O O O O o i n LENGTH OF • + 1 • + 1 * + 1 • + 1 + r + l \" + \\ + r O NASALS O o rH rH CM 0 0 o o + 1 o o o o o ON o o ON • • • • • • • • ON rH rH rH rH rH rH rH • CM CM CM CM CM CM CM CNJ CM INTERORBITAL o o O o O o o o O • • CONSTRICTION + f + f + 1 0 0 + f + 1 ON + f t - + f + r + f co CO ro CO ' ro co co co co • • • « • * • • BREADTH OF SKULL BASILAR LENGTH CO O + r vO CO o « + 1 i n ro O • + 1 vO CO O + 1 i n O + 1 co O • + 1 i n O + l\" vO ON VO O + 1 i n ON O N o + f oo ON i n O + 1 i n ON \\o o + f 0 0 o + 1 CM O ON • « CM rH CO O + 1 i n co O + 1 vO vO O + l\" CM ON 0 0 o + r o o CM C O o + i i n oo o i n ON oo o vO VO t - vO O N O N o o rH o O o O o o OCCIPITONASAL + 1 + r • + 1 • + 1 + r + f + r + r • + 1 LENGTH 0 0 i n 0 0 i n rH VO O vO i n vO co i n i n m co VO i n CM CM CM CM CM CM CM CM CM SAMPLE SIZE 0 0 O N VO m CM ON rH iz; o O CM o CM ON rH O O N < < CM i n & W • rH O 1—1 1—i o O Pi O Jz; iz; iz; iz; iz; SAMPLE GE C 3 o o Pi o. M Pi o o T T OR i—i o LT CO H iz; PH I—1 PH O PH iz; rH o < o CO rH M P H l—l PH l—i M P « .J w • o < < W -4 < -< P3 < s PH iz; o S o O s 'A o •H -P d •H t> CD rrH H cti PI cd -p 02 CD PI O + 1 CD on a rH CD !> a PI 0j CD P H E cr3 m Pi ^ •H 43 Pi U m pi -p d rH Pi O •H Pi m pi t> w !> S o 5H CD PH CD -P fH O =H CQ -P PI CD e 0 rH Pi m «3 CD B ce •H Pi o CO CD rH MAXILLARY TOOTHROW + POSTPALATAL LENGTH + + + + + + + + + + + + + DIASTEMA WIDTH + + + + + + + + + + + + + + PALATINE FORAMEN + + + + + + + + + + + SHELF OF BONY PALATE LENGTH OF NASALS + + + + + INTERORBITAL CONSTRICTION BREADTH OF SKULL + + + + + + + + BASILAR LENGTH + + + + + + + + + + + + + OCCIPITONASAL LENGTH + + + + + + + + + + + + + + SAMPLE SIZE SAMPLE * O f C N J r n T j - t r N r n T h i P v T f i n t n > > > > > > > > . -p x -P Pl •H CD rH 0 bD •H «h PH ca E Pl o •H -P & •H U -P V) •H o 0> W CM CM CM cn cn Tt-P W > W EH « ' ^ E H EH S g i i M M CO + + + pl •H u El Pnl Pl •H VI -P Pl CO E CD PS CO ca CD ca •H Pl ca u o Pl ca E Pi CD CD > -P CD 42 Pl o •H -P ca SH c3 !> o o Pi ca o •H <+H •H Pl bD •H CO Tt\" CD rH ca EH MAXILLARY TOOTHROW r H r H r H r H r H r H O O O O O O • • • • • • + 1 + 1 + 1 + 1 + 1 + 1 vfj vO \\ 0 ' TJ- N O in en cn en cn cn cn • • • • • • POSTPALATAL LENGTH cn cn cn cn cn cn o o o o o o + i +i +i +i +1 +i H - - r t r H CM H - m O N O N O N O N O N O N • • • • • • DIASTEMA WIDTH cn cn CM CM cn CM o o o o o o + \\ -H +i +i +i +i r - l 0 0 O N O O CM t— vO vO t- t— 't-• • • • • • PALATINE FORAMEN CM CM CM CM CM CM O O O O O O • • • • • • + | + | + 1 + 1 + 1 + 1 CM O r H CM CM cn in in in in in in • • • • • • SHELF OF BONY PALATE CM CM r H CM CM CM o o o o o o • • • • • • • +i +i +i +i +i -n r-- t~ t~ t- t- oo cn cn cn cn cn en • • • • • • LENGTH OF NASALS m T t rf- en m T T O O O - O O O + i +1 +i +i +1 +i O in -si- in O N CM r H O O O . O r H • • • • • * r H r H r H r H r H r H INTERORBITAL CONSTRICTION r-t r-i r-t r-i r H r H O O O O O , O + { + { + { + { + 1 + 1 t — 0 0 \\D 0 0 CO h -en en cn en cn cn • • • • • • BREADTH OF SKULL O oo O N en t~ en r H O O O O O • • • • • * + 1 + 1 + 1 + 1 + 1 + 1 i—i in cn ^ O T T CM CM CM r H en r H • . • • « • r H r H r H r H r H r H BASILAR LENGTH CM t~- in in t-— m r H O O O O O + 1 + 1 + 1 + 1 + 1 + 1 NO o O o cn oo o o o o o o • • • • * • CM CM CM CM CM CM OCCIPITONASAL LENGTH r— t— m . H- t— si ) o o o. o o o +1* +1* +1* +f \"• - • + 1 + 1 00 Tt\" O r H t— r H vO \\D NO V£> MD t>-• • • • * * CM CM CM CM CM CM SAMPLE SIZE SAMPLE TEXADA 76 SAVARY 22 THORMANBY 19 TEXADA 20 BEACH TEXADA 30 INTERIOR o •H -P ee •rrl > CD T i u a fl ca -P • ui CD a o + 1 , CD crj r l CD % fl ci CD B w fl CD •H W r l O CD W SI M r H CM CM rH CM CM CM CM PALATINE o . O • o • O O • o o • O • FORAMEN + f + 1 +1 + f + 1 + f + 1 + 1 CM o rH LfN o o CM rH C O in in LfN in in in in in in CM CM CM CM rH i H ' rH CM o o O o o O O o SHELF OF • • • • • • • • + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 BONY PALATE t- t> co t> t- t- c-ro C O C O C O co C O co C O co LT\\ co C O co O O o o o o o o LENGTH OF + l\" + f • +1 + 1* + l\" • + 1 + l\" + 1 NASALS l> o LT\\ O o VO O o r-T vO o co o o rH rH rH rH rH r H rH rH rH rH rH INTERORBITAL CONSTRICTION ro CM rH rH C O O N o O o O O O o o BREADTH • + i • + 1 • + 1 + r + l\" • + 1 • + 1 + 1 OF SKULL vO vO vO 0 0 CM in •<* o rH rH rH rH co co co rH CM rH rH rH rH rH r H rH rH rH CO C O in VO 0 0 VO O o O O o o O o BASILAR +1 + f + 1* + f + i\" + f + r + f LENGTH CM o rH O o o C O O N in rH o o o o CM O vO O CM CM CM rH CM CM CM CM CM 0 0 0 0 -<* co vO vO O o o o o O o o vO in 0 0 OCCIPITONASAL + l\" + f + r • + 1 + r • + 1 • + 1 • + 1 C O O N O N VO O N LENGTH ^ vO vO VO vO 0 0 in vO vO co vO o vO rH VO O N vO rH rH rH CM CM CM CM CM CM CM CM CM £ •H Pi •H •H SAMPLE SIZE CO i—1 O N 0 0 rH rH 0 0 C O rH rH rH CO rH O in ed ed ed < « < X > w < o to m * *' * PH FH * + pq < RM AD o X O K PQ EH EH + + + -p -p -p o o o a> a> 0 o o o o o o Pi o •H -P •H r> 0 r l crj Pi -p co 0 PI o + 1 0 bo cd r l 0) ' > Pi 0 E 0 0 vO ON PI in N t ON VO co ON PI •H a> -P o 0 o o CO •H CO PI 0 •H &4 r l o 0 bd r H r H r H r H r H CM i H r H O O O o o o O o El + f + l\" + 1 + 1 + 1 + f + 1* + 1* m t - 1-- VO ON t - ON in 0 0 PHI co C O co C O C O C O C O ro C O r l o . r H ON r H ON ON in CM TT O CM O ON r H o CM 0 0 CM CM CM CM r H CM CM CM CM CM CM CM in in in TT 0 0 ON O r H O O O o o o o o O C C I P I T O N A S A L + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + ! L E N G T H vD CO r H r H in TI- TT in in I> t - 0 0 VO ON vO NO 0 0 CO ON ON CM CM CM CM CM CM CM CM CM CM ON t>H o PH TT CM EH CO rt i n < r J o < pq oo CM EH VO cn < EH EH 1—1 rH CO w' C±3 rg PH 1—i o o t> P3 o cn to CM VO CJ3 I—I EH o o rt bo pq Pl >H r l P3 EH P! o •rl -P ce •H t> CD ^ r l c6 T3 Pl ca -p to CD Pl O + 1 CD bo a r l CD > ca PI ca CD E to rd Pl CS r H CO •rl Pl r l CD 43 -P u o P! CD 43 -P E o r l Pl CD 44 ca -p CO Pl o •rl - P O CD i—I r H O CJ r l o m -P Pl CD E CD r l fl CO ca CD E ca •H P! ca r l C_> ON 42 ca EH Mean - s t a n d a r d d e v i a t i o n minimum and maximum ISLAND TOTAL LENGTH BODY LENGTH TAIL LENGTH HIND FOOT LENGTH N DOYLE 213-9 -177-235 11 -8 110-6 ± 7. 95-123 0 103.2 ± 6.1 82-112 23.0 ± 22-24 •7 21 HURST 210-3 ± 165-228 13 -0 105.6 ± 8-73-114 0 104.3 i 6.8 84-118 23.7 ±1 20-24 .2 25 BALACLAVA 187-1 -165-206 8 -2 91 -3 ± 5-81-106 9 97-5 ± 5.3 83-108 21.4 ± 20-23 -8 47 NIGEI- 212.9 ± 194-280 13 .3 108.4 ± 6. 99-125 0 104.4 ±12.4 87-108 24.8 ± 23-26 .8 59 VANSITTART 197-0 ± 186-270 7-9 101.2 - 2. 96-106 5 95-8 ± 7.1 85-110 22.0 ± 21-23 -4 15 HOPE 189-9 ± 165-225 9.8 92 •9 ± 8. 76-121 4 97.1 ± 4.9 79-116 21.6 ± 20-24 -9 78 COX 209.3 ± 125-234 17.6 108.7 ± 7.3 90-125 103.0 ± 5 . 9 88-112 25 .0 ±1 21-27 .3 43 LANZ 208. 9 ± 189-239 10.2 106. 8 ± 7. 94-128 7 102.1 ± 5.3 93-116 25 .4 ± 23-27 .9 56 TRIANGLE 224.8 ± 187-250 10.9 116. 4 ± 9. 89-130 1 104.9 ±12.4 93-116 26.5 % 24.5-29 -1 67 BOWEN 173.0 + 154-200 8.5 79. 1 ± 4. 75-98 6 94.0 ± 6.6 80-116 19.6 -21-23 .6 34 THORMANBY 178.6 ± 153-194 9.5 8 678- 49l 4- 5 92.3 ± 6.7 72-100 21 .1 £ 19.5-23 -9 26 TEXADA 176.7 ± 156-201 11.3 7861-V3 9\" 6 97.8 ± 4.3 90-108 22.0 ± 20.5-23 -7 62 SAVARY 175.1 ± 160-197 8.0 M 4- 1 93.4 ± 5.6 85-110 21 .6 ± 20-23 -9 32 MAXILLARY TOOTHROW o o o o r H r H r H r H O r H • • o O o O o O + 1 +1 • + 1 • • 0 0 ON + i + 1 + i +1 + 1 co co vO ON LfN ON ON ON • • CO CO CO CO CO co BREADTH OP SKULL CO CM ro CO CM CM co CM POSTPALATAL O • o o o o o O o LENGTH + 1 + 1 + 1 + ? + ? + i + i \"TO r H 0 0 CM O CO 0 0 o Q ON ON • ON ON ON • r H • • r H • • • r H co r H CM CM CO r H CO CM DIASTEMA O o O O o o o O +\"l +\"l + i + i + i + i • + 1 • + 1 WIDTH o ON ON CO o o o 0 0 t - vO 0 0 t - 0 0 0 0 0 0 r H r H CM CM CM CM CM r H O o o O O o o o PALATINE +'l +\"l + i + \\ + i • + 1 +i • + 1 FORAMEN vO CM vO CM LfN o vO r H LfN o vO r H VO o VO o O . o o o O O O r H r H r H CM r H r H CO r H o O O O O o o o SHELF OF +1 +l\" +1 +1 • + 1 +1 +i +1 BONY PALATE l> o t~ LfN 0 0 CM co CO f^\" CO •vt CNJ CO co o O o o o o O o LENGTH OF + r + 1* + 1* + l\" + 1* + l\" • + 1 + l\" NASALS CNJ r H LfN CM vO o ON r H r H r H ON r H vO r H CM r H r H r H r H r H r H r H r H o r H r H r H r H r H r H r-t O o O O o O o o INTERORBITAL + f • + 1 * + 1 + l' • + 1 + |\" + l\" + 1 CONSTRICTION CN] o ON co o ON CO o •<* r H •<* o d o d o o o d o CM o + 1 H/ CM CM o + 1 LfN CM CM O + 1* C— CM o CM co O + 1 LfN O + 1 r H CM CO o + l\" co CM r H o + 1 CM r H r H r H r-A r H r H LfN vO LfN LfN vO o o o o o O o o BASILAR + 1 + 1 + 1 + 1 + 1 + 1 + ] + 1 LENGTH 0 0 r H ON r H 0 0 ON CM o o o CM o CM 0 0 CM CM CM r H CM CM CM CM CM LfN LfN LfN LfN LfN 0 0 • * p q SAMPLE * * LA * c i pq EH o r H * * r J CO P3 pq * < >H PS 03 r H S3 r H o < r H o o ai o K o i-q EH r H CD P n r H S- PH ce B m cZ Vi vO CO CM ON LfN r H ON CD r £ -P u o w - p PI CD B CD SH Pi w cZ CD e r H CCJ •H Pi i—i EH rt < EH EH I—i CO CD T3 r d H ca Pl ca -p to + 1. CD W> ca u CD > ca PI ca CD E rH PI o r H en r H r H r H CM r H en r H Pl O O o O o o O O O o .p-l + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 -p CO in Tl- l > 0 0 r H en in CJ cn cn en Tt- en en Ti- TT TT CD r H o CJ o t-O N rH I 0 0 VO O N CD - P U o <*H to - P Pl CD E CD rf fl to ca CD S ca •H Pl ca u o < CM rH 42 ca rH MAXILLARY TOOTHROW r H ' O r H l H O O r H r H r H O O O O O O O O O O O +i +\"l +\"l +*l +\"l +\"l +\"l -M - t j +*l r ^ O N m O N c o m o o O N C N O N c o c o c o c o c o c o c o c o c o c o C M C M C M C M c o c o c o m co o o o o o o o o o o + d v ti ti v P v +^ O O N O N O C N O N O N O N Q O N f-^ • • rl • • • ' M * CO CM CNJ CM CNJ CO CO Xt\" CO H / o o o o o o o o o o + \"l HH +1 + 1 + 1 +1 + 1 + 1 + 1 +i CO O O Ti\" rH rH rH rH ^ t \" ^ t r ^ o o t — c o t - - o o o o o o C O C O CM rH rH CM CM CM CO CO CM rH O O O O O O O O O O + 1 +i +i +i +1 +i +i +i +i +i C M C M C O r H C M r H r H O O O v O v O L n v O m m v O v O v O v O O r H i — I C M r H C M C M c O r H C M O O O O O O O O O O + 1 + 1 +*l +\"l +\"l + 1 +*l +*l +\"l +*l t - O t ^ m l ^ - O O r H - H - m v O CO - t rO H / f O | (sr>, ^ ^- . ^j. \" 1 5 3 3 S co in L7N in O O O O O O O O O O ,_ + i +i +i +f +f +i + ; + j + j + ; g rH in oo O N CNJ o o T o i n T - - , H r H CM O r H O r H ^ ,_, fs j CN, -P • • • • * . . . . ro rH rH rH rH rH rH __, i—| rH rH'r1 , > - ON CM oo ™ O O O O O O O O O ^ + 1 J 00 + 1 +l + 1 + 1 +l + 1 + 1 + 1 + 1 ' % r - i r H O t — H / C M r H r H r H t - ™ C M O C M O O C M C M C M C M ^ . . . . . . . . . a CM CM CM CM CM CM CM CM CM ™ • C M C M C M C M C M C M C M C M C M C M O NO m l ^ r d ^ ~ t— co oo i—! i—I CM CO CO i—I CM CM H^ |> < l l z ; M f q p ! O p - a j M - a i O O - a J C t i r H M o m p q ! z ; > > W O H J E H in EH P0STPALATAL LENGTH DIASTEMA WIDTH PALATINE FORAMEN SHELF OF BONY PALATE LENGTH OF NASALS INTERORBITAL CONSTRICTION BREADTH OF SKULL BASILAR LENGTH 0CCIPIT0NASAL LENGTH SAMPLE SIZE SAMPLE MAXILLARY TOOTHROW POSTPALATAL LENGTH DIASTEMA WIDTH PALATINE FORAMEN SHELF OF BONY PALATE LENGTH OF NASALS INTERORBITAL CONSTRICTION BREADTH OF SKULL rH rH rH rH O O o o • • • • + 1 + 1 + 1 + 1 OO OO m 0 0 co co C O co +4 co rH o rH o O o O o « • • • + 1 + 1 + 1 + 1 i n O N 0 0 O N co co C O C O - L f\\ -O < 9 + 1 o o co' Th Th rH C O Tt\" C O O o O o O Q._ O +1* • + 1 + f +f + \\ +f +1* 0 0 CN] O N VO Th t - t -O N O N O N O N O N O N O N Th o i n O CO O CN] o +1 O N +1 t - O N vO + 1 CM C O o +1 rH d C O o Th o C O o + 1 o + 1 O N + 1 O 0 0 CM o • +! CO vO Th o +i ON m co O +'\\ C O i n CM O +i o vO + 1 CM i n CM O +i CM i n co O + 1 O VO CM o • + 1 o vO +1 t -co co O +l\" 0 0 co + 1 vO C O + 1 co Th o O + f 0 0 C O CM o + 1 0 0 CO CM o + 1 Th d CM O + 1 co Th o co O oo O Th o co o o o i n O in O m O +1 CM + 1 O N + 1 VO O + 1 0 0 + 1 CM O + 1 O + 1 O N + 1 h -O + 1 rH Th O rH o +f o Th O O + 1 O N co + 1 O N co + 1 O N C O + 1 CO co +1 O Th + 1 Th d CM O + 1 C O CM Th O CM O Th O co O CM o co O + 1 CM CM + 1 + 1 rH CM + 1 h -O +1 i n +1 O N + 1 C O CM 0 0 o co o o m O h -o O N o oo O m O + 1 CM o C O o + 1 Th oo CM o +'\\ CD vO CM o • +1 Th Th i n O + 1 Th CM + 1 CM Th CM O + 1 Th CM 0 0 o BASILAR +i + 1 + 1 +i + 1 +i +i + 1 + 1 LENGTH vO Th CO CM Th CM t- ON O N rH rH ON CM O o rH rH CM CM CM rH CM CM CM CM CM CM m i n VO h - i n 0 0 CO 0 0 0 0 O rH o O O o o o o 0CCIPIT0NASAL + 1 + i + i +i + 1 + i +1 +1 +! LENGTH vO h - CM 0 0 o vO ON 0 0 i n vO Th vO CM 0 0 co 0 0 Th ON CM CM CM CM CM CM CM CM CM SAMPLE SIZE o CM OO C O O i n Th Th 0 0 rH EH co rH rH co < rt < pq SAMPLE < EH EH W EH o M l—l S3 co < CO pq X SI rt rJ Ci3 rt i—1 O £> < 1—1 < o O < rt Q pq |2i > sn o EH Pl o •H - P crj •H > rH H CS r d Pl cd -P m + I . 0) tuO cr3 U 0) > crj Pl ca s w Pl o •H - P o CD O O Pl o m CD rH Cd a CD m - P Pl CD S CD u pi m ca CD E ca •H Pi ca O n 0 1 I I 1 I I I 70 20-04-T A I L L E N G T H I l l I l I i 126 15-0. 10-0.. 5-0.. 0-0. 4 70 AO -O-i B O D Y / T A I L R A T I O 12G 30 <0.. 20 .0 . . 10 «0-0-0. 0»5 1-5 15»0._ iO-0. . 5.0. 70 E0-0 .L. -ft ft T A I L L E N G T H IEB 15 .0 . l O C L . 5*0. 0-0. ft 70 40*0+ ft4 r B O G Y / T A I L R A T I O I E 3C iO-0_. 0«5 1«5 15-OJ .SAVARY ISLAND 10 -OJ 5-0j 0-0J 4 70 T A I L L E N G T H - f l - I 1 I 1 I 1 I 12G 15-OJ 10-OJ 5-01 0-OJ 70 4 0 - O J B O D Y / T A I L R A T I D 1EG 30 .01 20 .01 10'Oj O - O J B O D Y L E N G T H 10»0J 5-01 O ' O J 70 ?0*0J T A I L L E N G T H M M 1E6 15 \"OJ 10 .01 5-0j 0«0J - H -70 40 \"Oj B O D Y / T A I L R A T I O 1ES 30« OJ 3>0J 10 -0. 1 5 » 0 _ . 1 0 - 0 . . i-0._ O'O. 7 0 2 0 - 0 + T A I L L E N G T H 1 5 G 1 5 - 0 . 1 0 . 0 . . 5 » 0 . 0 - 0 . 7 0 - H -4 0 . O J B G G Y / T A I L R A T I O 1 2 6 3 0 * 0 . . E?0«0.. 1 0 . 0 . . 0 * 0 -B Q D Y L E N G T H 1 5 - O J 10'OJ 5 - O J 0 - O J 7 0 2 0 - O J T A I L L E N G T H 1 2 G 1 5 - 0 1 1 0 - O J 5 - O J 0 - O J ++ I I I f l I I I I I I I I I I I | | | 7 0 4 0 - OJ. B O D Y / T A I L R A T I O 1 2 G 30-Ol 2 0 - 0 1 1 0 - 0 . APPENDIX 3 DISCRIMINANT ANALYSIS DATA APPENDIX 3 DISCRIMINANT FUNCTIONS c o e f f i c i e n t s legend s k u l l l e n g t h s k u l l b r e a d t h l e n g t h of n a s a l s p a l a t i n e s l i t P o s t p f a l a t i n e s l i t b a s i l a r l e n g t h i n t e r o r b i t a l c o n s t r i c t i o n s h e l f o f bony p a l a t e diastema m a x i l l a r y toothrow l e n g t h of a n i m a l body l e n g t h t a i l l e n g t h h i n d f o o t l e n g t h Doyle I s l a n d c o n s t a n t ; -1125.14136 c o e f f i c i e n t -10.95095 -41.16622 115.58285 -226.40087 8.93644 388.15087 0.63262 -0.65659 0.27753 1393.79638 242.75891 16.12768 135.38287 1466.40918 H u r s t I s l a n d c o n s t a n t ; -1155.21997 c o e f f i c i e n t ' 8.15174 -83.03508 112.45332 -212.10366 9.56216 406.14080 0.76581 -0.91500 0.22558 1293.95312 206.02777 214.87585 1553.04370 16.49320 B a l a c l a v a I s l a n d c o n s t a n t ; -979.97265 c o e f f i c i e n t 0.95112 -62.83573 -169.53933 7.32085 0.68174 -0.91393 99.29972 1321.77954 161.97552 305.24835 258.00543 1345.94604 0.23036 15.21731 N i g e i I s l a n d c o n s t a n t ; 1159.56103 c o e f f i c i e n t -8.98146 _54.98657 100.85078 1279.41699 165.33013 -114.14604 5.09999 429.90661 228.24316 1490.66235 V a n s i t t a r t I s l a n d c o n s t a n t ; -97.68335 c o e f f i e i e n t 16.83068 -61.70179 64.80624 -148.75589 5.71217 279.70916 0.49978 -0.56468 0.27029 1399.22436 113.95394 290.26428 1228.05469 16.36004 Hope I s l a n d c o n s t a n t ; -984.45080 c o e f f i e i e n t -1.24584 -64.11415 -133.79235 6.17992 0.61364 -0.88389 97.19392 1281.33203 175.89895 303.12951 273.11566 1341.25610 0.23543 15.30642 Cox I s l a n d c o n s t a n t ; -1154.35473 c o e f f i c i e n t -0.98899 -62.37367 101.25082 -159.94216 7.01263 409.82568 0.61067 -0.73399 0.29151 1325.34765 174.05728 200.53790 1492.62720 18.19372 Lanz I s l a n d c o n s t a n t ; -1170.90210 c o e f f i c i e n t -12.63926 -48.35587 102.98414 -119.78697 5.24048 417.34265 0.61158 -0.82431 0.26982 1347.10400 160.96511 196.18627 1482.98535 19.0298 T r i a n g l e I s l a n d c o n s t a n t ; -1238.74145 c o e f f i c i e n t -6.99522 -62.34459 104.68608 -121.41917 5.63358 389.93750 0.58385 -0.65399 0.35650 1348.99634 185.62478 232.68136 1455.26855 19.99827 Bowen I s l a n d c o n s t a n t ; -941.91906 c o e f f i c i e n t -34.08764 -28.06115 129.70477 -145.81207 . 6.45590 349.13821 0.55917 -1.09760 0.23716 1124.55566 253.90820 15.67136 163.08029 1382.68359 Thormanby I s l a n d constant; -939.92675 c o e f f i c i e n t -5.44735 -46.25228 92.12721 , 1292.68823 144.65267 -145.16732 6.13494 313.63641 268.43298 1300.15503 0.52232 -0.89130 0.25322 15.17016 Texada I s l a n d constant; -996.96435 c o e f f i c i e n t -12.39646 -52.04350 111.96975 1196.63550 177.41284 -153.53219 6.93321 341.904066 284.60461 1398.46069 0.60903 -1.26903 0.24885 15.61571 Savary I s l a n d constant; -981.61413 c o e f f i c i e n t -15.51098 -49.00769 115.29104 1262.45849 168.59378 . -154.90383 6.84798 288.40869 305.41015 1350.46411 0.50345 -0.98707 0.23160 15.83843 I s l a n d N D i s c r i m i n a n t a n a l y s i s d e v i a t i o n s from expected. Doyle Hurst N i g e i Hope Cox Lanz T r i a n g l e Bowen Texada Savary 20 24 B a l a c l a v a 42 54 V a n s i t t a r t 14 75 31 37 61 14 Thormanby 19 73 19 Hurst (1) Cox (2) Hope ( l l ) , Thormanby (5) Texada ( l ) V a n s i t t a r t (2) Lanz (10), Cox (2), Hurst (2) T r i a n g l e (2) none B a l a c l a v a (12), Cox (4), Bowen (3), Thormanby (8), Savary (2) Hurst (4), N i g e i (2), Lanz ( 7 ), T r i a n g l e (4) Cox (8), N i g e i (2), T r i a n g l e (7), Hope (1), Hurst ( l ) N i g e i (2), Lanz ( 6), Cox (5) Texada ( 3), Thormanby (2), Savary ( l ) , B a l a c l a v a ( l ) Savary (2), Hope (2), B a l a c l a v a ( l ) Savary (6), Bowen (12), Thormanby (3), Hope ( l ) , Bowen ( l ) , B a l a c l a v a (2) Table 22A T n e d e v i a t i o n s from the c o l l e c t i o n l o c a l i t y based upon d i s c r i m i n a n t a n a l y s i s . Sample s i z e s i n d i c a t e d by the bracketed v a l u e . APPENDIX 4 KARYOTYPES OP INSULAR PEROMYSCUS A A A A A * A A * KX X ft I fl H *»« j ^ /)(! fi A I Y O A ; x Y f\\ A A A A A A *» A c » Peromyscus m a n i c u l a t u s g e o r g i e n s i s Bowen I s l a n d (-32C/62 11') A t y p i c a l , s m a l l b o d i e d , low P.N. ( 7 4 ) , c o a s t a l m a n i c u l a t u s . T h i s k a r y o t y p e i s r e p r e s e n t a t i v e of the Thormanby, Savary, V a n s i t t a r t , and Hope I s l a n d p o p u l a t i o n s of Peromyscus. iuixi'utxtiiiu' Unih | M « Cox I s l a n d (148) Peromyscus s i t k e n s i s i s o l a t u s * This karyotype i s t y p i c a l f o r the l a r g e morph i n s u l a r Peromyscus Mllixitxitt*** j f J N i g e i I s l a n d ( E l ) Peromyscus s i t k e n s i s i s o l a t u s * Doyle I s l a n d ( l l ) Peromyscus s i t k e n s i s d o y l e i * x r e v i s e d nomenclature *% M ft * H A A » » « Jf # H mm mm #• A /% m) Texada I s l a n d (229) Peromyscus m a n i c u l a t u s g e o r g i e n s i s t i l l I M A l I S I I I fli Hope I s l a n d (174D) Peromyscus m a n i c u l a t u s g e o r g i e n s i s H u r s t I s l a n d (E19) Pe romyscus s i t k e n s i s saxamans APPENDIX 5 SPECIMENS EXAMINED APPENDIX 5 SPECIMENS EXAMINED U.B.C. The U n i v e r s i t y of B r i t i s h Columbia V.P.M. The B.C. P r o v i n c i a l Museum, V i c t o r i a M.V.Z. The Museum of V e r t e b r a t e Zoology, B e r k e l e y M male,P female UbC ubC UBC UBC VP I'M VPM VPM 013M 2 3 5M 016M 1196M 379 0M 378 7M 37 8 4M UBC UBC UBC VPM VPM VPM 012M 2 34M 015M 37 9 3. , 37 8 9M 37 8 6M UBC UBC UBC VPM VPM VPM 2 3 6M 2 7bM 1 19 5M 3 79 1M 376bM 3 76 5 i-'i DOYLE ISLAND UBC U18M UBC 022M VPM 3674M VPM 36 71M VPM 3663M VPM 366 5 M VPM 3662M VPM 3659M HURST ISLAND UBC 12 06M UBC . O20M VPM 36 73M VPM 36 7 0M VPM 36 6 7M VPM 36 64M VPM 36 61M VPM 36 5 8M UBC 019M UBC 120 7M VPM 3 67 2M VPM 3 66 9M VPM 3 66 6M VPM 3 66 3M VPM 3 66 0M VPM 3657M VPM 3 3 Z 6 M VPM 38 3 2M VPM 3833M VPM 38 3 3M V P M 38 3 9M VPM 38 4 5M VPM 3846M VPM 38 48M VP. . 3850M VPM 38 5 iM VPM 38 2 9M VPM 3 82 7M VPM 38 6 6M VPM 38 64M VP.-i 38 6 3M VPM 38 62M V P M 38 6 1M VPM 38 6 0M VPM 38 5 9M V P M . 38 5 4M 'VPM 3 3 49M VPM 364 7M UBC 1202M UBC 1 2 0 3M VPM 384 1M V P M 3 86 5 M VP I-I 38 5 8M VPM 38 57M ' VPM 3 8 56 M VPM, 3 8 5 5 M VPM 38 5 3M V P M 38 5 2 M UuC 0 3 0M UBC 02 6M UBC 023.-. UBC 2 4 9M UBC 2 7 5M UBC 274M UBC 0 2 9 M UBC 02 4M UBC 0 3 1M UBC 2 5 0M UBC 2 7 6M UbC 01 OM UBC 0 2 7M BALACLAVA ISLAND UBC 1 4 6 M U B C 13 8 M U B C L 1 2 M UBC L 0 5M U B C E 0 3M UuC IH -GM U B C 1 3 9M U B C 1 3 7 M UBC 1 4 4 M UBC U B C 1 3 6 M U B C L 1 6 M UBC U B C B U M UBC L C 2 f-UBC E 0 1 M N U B C VPM 3 69'nM VP,- , 3 6 9 7M V P M 3 7 0 8 M VPM 3 7 1 Ci-; VPw 3 7 1 8 M V P M 3 7 1 9 M VPM 3 7 2 1 M V P M 3 7.2 a M V P M 3 7 2 9M VPM 3 8 4 4 M VPFi 3 7 2 2M V P M 3 6 9 6M VPM 3 6 9 5M V P i-i 3 6 9 3 M V P M 36 9 2 M VPM 3 6 9 IM V P M 3 6 9 9M V P M 3 7 0 IM VPM • 3 7 0 3 M V P M 37 0'nM V P M 37.0 5 M V P M 3 7 C 6 M VPM 3 7 U 7 M V P M 3 7 0 9M VPM 3 7 in-; VP;- , 3 7 1 2 M V P M 3 7 1 3 M . VPM 3 7 14-M V P M 3 7 1 5M V P M 3 7 1 7 M VPM 3 7 2 0 M VPf-i 3 7 2 3M V P M 37 2 4 M VPM 3 7 2 5M V P M 37 2 6M V P M 37 2 7 M U B C E 1 5 M UBC E 0 8M NIGEI ISLAND UBC 1 7 0M U B C 13 4M UBC 17 5M U B C 12 8M UBC 1 3 I M U B C 1 6 9M U B C 1 3 0 M U B C 1 3 5 M U B C 1 2 5 M U B C 12 7M U B C 17 8M U D C 1 2 4 M ULSC 1 3 2 M U B C 12 9M U B C U0 9M VANSITTART ISLAND U B C 0 0 7 M U B C 0 0 6 M U B C OOH-M U B C 0 0 2 M U B C 0 0 I M U B C 12 3M U B C 12 1 M U B C 2 3 7M U B C 2 7 2M U B C 2 7 1 M U B C 1 7 4 M U B C 2 5 5M U B C 2 5 2M U B C 2 5 3M U B C 2 5 4M U B C 0 0 3M U D C 0 0 5M U B C 2 7 0M U B C 2 5 8M U B C 2 4 8M U B C 17 3M U B C 2 5 7M U B C 28 6M U B C 2 6 9M U B C U B C 2 4-7M U B C 2 5 I M U B C 2 7 9M U B C 2 ' f 6 M V P M 3 7 7 7M HOPE ISLAND VPM 3738M VPM 3746M VPM 3752M VPM 375 9M VPM 3764M VPM 3772M VPM 37 3 6M VPM 37 5 5M VPM 375 8M VPM 377 0M VPM 3773M UBC 2 5 6M HOPE ISLAND VPM 37 39M VPM 3748M VPM '3753M VPM 3760M VPM 376 5M VPM 377 5M VPM 37 3 7M VPM 37 56M VPM 37 61M VPM 37 6 9M VPM 37 6 8M UBC 245M VPM 3741M VPM 3 75 1M VPM 37 5 4M VPM 3 76 3M VPM 3767M VPM 3 776M VPM 3 7 40M VPM 3 757M VPM 3 762M VPM 3 771M UBC 277M VPM 37 4 5M UBC 162M VPM 5606M VPM 5609M VPM 5613M VPM 5605M VPM 5621M VPM 5626M UBC 105M UBC 147M UBC 055M UBC 15 9M COX ISLAND UBC 105M VPM 5607M VPM 5610M VPM 5615M VPM 5619M VPM 5623M VPM 5627M UBC 102M UBC 14 8M UBC 165M VPM 5 604M VPM 5 60 8M VPM 5611M VPM 5 6 16M VPM 5 620M VPM 5 62 5M UBC 10 9M UBC 10 3M UBC 162M UBC 15 7M UBC 117M UBC 112M UBC 12 0M UBC 04 2 M UBC 0 50M UBC 0 5 3M UBC 113M UBC 119M UBC 0 5 2M UBC 051M UBC 118M UBC 04 1M VPM 55 8 0M VPM 558 1M VPM 5 58 3M VPM 5585M VPM 5589M VPM 5 59 0M VPM 5591M VPM 5600M VPM 5 60 1M VPM 5602M VPM 5 57 7M VPM 5 57 8M VPM 5582M VPM 5 5 84M VPM 5 58 6M VPM 5587M VPM 5 5 92M VPM 5 59 3M VPM 5594M VPM 5595M VPM 5 59 6M VPM 559 7M VPM 5 59 8M VPM 5 60 3M LANZ ISLAND UBC 9222M UBC 9221M UBC 92 17M UBC 9216M UBC 9 2 29M UBC 9233M UBC 9232M UBC 92 2 3M UBC 9 23 IM UBC 92 3 0M UBC 92 27M UBC 9 2 26M UBC 9225M UBC 92 24M UBC 921AM UBC 9215M UBC 9218M UBC 9219M UBC 9220M UBC 50 9M UBC 50 3M UBC S06M UBC 508M UBC 18 0M UBC 063M UBC 06 AM UBC 0 6 5M UBC 069M UBC 18 8M UBC 19 IM UBC 19 7M UBC 189M UBC 18 3M UBC 16 5M UBC 192M UBC 19 8M UBC 17 9M UBC 181M UBC 18 6M UBC 066M UBC 0 6 8M UBC 0 7 0M VPM 545AM VPM 54 5 7M VPM 5 A5 2M VPM 5AA9M VPM 5AA8M VPM 5 AA3M VPM 5442 M VPM 5441M VPM 5AA0M VPM 5AA AM VPM 5AA5M VPM 5 A A 6 M VPM 5447M VPM 54 5 0M VPM 5 A5 IM VPM 545 3M VPM 5A5 5M VPM 5 A5 6M VPM 54 5 8M UBC 190M rRIANGLE ISLAND VPM 68820M VPM 68819M VPM 688 18M VPM 6 594 6M VPM 6 5947M VPM 65952M VPM 65972M VPM 6 595AM VPM 65948M VPM 6 595 3M VPM 6 59 73M VPM 6 5 97AM VPM 33 8 3M VPM 33 8 AM VPM 3A5 IM UBC 875 IM UBC 67 5 2M UBC 87 5 5M UBC 8753M UBC 033M. UBC 0 3 5M UBC 034M UBC 87 5 AM UBC 03 IM UBC ODJM UBC 0 3 2M VPM 68 816M VPM 68815M VPM 68 817M LANZ ISLAND UBC 262 M UBC 2 59M UBC 2 6 0M UBC 218M UBC 219M UBC 2 2 0M UBC 222M UBC 216M UBC 2 2 1M THORMANBY ISLAND UBC 263M UBC UBC 261M UBC UBC 2A2M. UBC VPM 7042 AM UBC THORMANBY ISLAND UBC 012M UBC UBC DOBM UBC UBC DOEM UBC UBC DOHM UBC UBC 213M UBC UBC DOIM UBC UBC 1783M UBC UBC 1769M UBC UBC 22AM UBC UBC 267M UBC UBC 210M UBC UBC 2 0 7M UBC UBC 2 8 0M UBC UBC 2 3 1M UBC UBC 2 2 5M UBC UBC 266M. UBC UBC 213M UBC UBC 202M VPM VPM 70398M VPM VPM 70A01M VPM VPM . 70399M VPM VPM 70A16M VPM VPM 70A06M VPM VPM 70A22M UBC UBC 26 5M UBC TEXADA ISLAND VPM 70378M VPM VPM 70388M VPM VPM 70385M VPM UBC 00 9M UBC UBC 002M UBC UBC 00 8M UBC UBC D0 5M UBC UBC M 26 AM UBC 2A IM 15 2M UBC 2A0M 2A3M VPM 70A2bM 15 3M 01AM UBC DO AM DO CM UBC DO DM DOFM UBC DOGM 015M UBC 013M 016M UBC 0 0 3M 1781M UBC 178 2M 17 8 5M UBC 1 78 6M 215M UBC 28 3M 2 2 8M UBC 2 3 0M 2 68M UBC 2 8 2M 2 11M UBC 20 9M 2 06M UBC 2 0 AM 2 33M UBC 23 2M 2 29M UBC 2 2 7M 2 3 8M UBC 2 8 AM 2 81M . UBC 2 1AM 2 12M UBC 20 5M 70A08M VPM 70A11M 70A15M VPM 70A 1AM 70A0AM VPM 7 0A0 7M 70A12M VPM 7OA13M 70A03M VPM 70A0 5M 70A21M VPM 70A0 2M 2 39M UBC 2 2 6M 178 8M 703 8 3M VPM 70 3 8AM 7039 IM VPM 70 3 8 9M 7038IM VPM 70 3 8 7M D0 6M UBC D0 7M 00 5M UBC G0 6M 0 1OM UdC D0 3M M UBC M M V Z 5 4 0 1 9 M M V Z 5 4 0 2 0 M M V Z 5 4 0 2 1 M M V Z 5 4 0 2 2 M M V Z 5 4 0 2 3 M •MVZ 5 4 U 2 4 M M V Z 5 4 0 2 5 M M V Z 5 4 0 2 6 M M V Z 9 5 9 8 7 M M V Z 9 5 9 8 8 M M V Z 9 5 9 8 9 M M V Z 9 5 9 9 0 M i - IVZ 8 8 8 9 0 M M V Z 9 4 3 6 3 M M V Z 9 4 3 6 4 M M V Z 9 4 3 6 7 M M V Z 9 4 3 6 6 M M V Z 5 4 0 1 7 M M V z 5 4 0 1 8 M M V Z 5 4 0 2 8 M M V Z , 5 4 0 2 9 M M V Z 5 4 0 3 0 M M V Z 5 4 0 3 1 M M V Z ' 5 4 0 3 2 M M V Z 5 4 0 3 3 M M V Z 5 4 0 3 4 M M V Z 5 4 0 3 5 M M V Z 1 2 0 5 8 0 M M V Z 1 2 0 5 8 1 M M V Z 1 2 0 5 3 2 M M V Z 1 2 0 5 8 3 M M V Z 1 2 0 5 8 4 M M V Z 1 2 0 5 8 5 M M V Z 1 2 0 5 8 6 M M V Z 1 2 0 5 8 7 M M V Z 1 2 0 5 8 8 M M V Z 1 2 0 5 6 9 M M V Z 1 2 0 5 9 0 M M V Z 1 2 0 5 9 1 M M V Z 9 9 7 5 3 M M V Z 9 9 7 5 4 M M V Z 9 9 7 5 5 M M V Z 1 0 1 6 4 6 M M V Z 1 0 1 6 4 7 M M V Z 1 0 1 6 4 8 M M V Z 1 0 1 6 4 9 M M V Z 1 0 1 6 5 0 M M V Z 1 0 1 6 5 1 M M V Z 1 0 1 6 5 2 M M V Z 9 6 2 6 0 M M V Z 9 6 2 6 1 M M V Z 9 6 2 6 2 M , M V Z 9 6 2 6 3 M M V Z 6 7 1 9 0 M M V Z 6 7 1 9 1 M M V Z 6 7 1 9 2 M M V Z 9 6 2 5 8 M M V Z 9 6 2 5 9 M M V Z 1 3 5 4 4 0 M M V Z 9 5 6 7 2 M M V Z 9 5 6 7 3 M M V Z 9 5 6 7 4 M M V Z 9 5 6 7 5 M M V Z 9 5 6 7 6 M • M V Z 9 5 6 7 7 M M V Z 9 5 6 7 8 M M V Z 9 5 6 7 9 M M V Z 9 5 6 8 0 M M V Z 9 5 6 8 1 M M V Z 9 5 6 6 2 M M V Z 9 5 6 8 4 M M V Z 9 5 6 8 3 M M V Z 9 5 6 8 6 M M V Z . 9 5 6 8 7 M M V Z 9 5 6 8 8 M M V Z 9 5 6 8 9 M M V Z 9 5 6 9 0 M M V Z 9 5 6 9 1 M M V Z 9 9 5 7 9 M M V Z 9 9 5 8 0 M M V Z 9 9 5 8 1 M M V Z 9 9 5 8 2 M M V Z 9 9 5 8 3 M M V Z 9 9 5 8 4 M M V Z 9 9 5 8 5 M M V Z 9 9 5 6 6 M M V Z . 9 9 5 8 7 M M V Z 9 9 5 6 8 M M V Z 9 9 5 9 0 M M V Z 9 9 5 9 1 M M V Z 9 9 5 9 2 M M V Z 1 1 3 1 4 7 M M V Z 1 1 3 1 4 8 M M V Z 1 1 3 1 4 9 M M V Z 1 1 3 1 5 0 M M V Z 1 1 3 1 5 1 M M V Z 1 1 3 1 5 2 M M V Z 1 1 3 1 5 3 M Peromyscus m a n i c u l a t u s gambeli M V Z M V Z M V Z M V Z M V Z M V Z M V Z 9 4 3 9 3 M 8 3 8 3 0 M 8 3 6 3 3 M 8 3 3 3 5 M 8 3 8 4 0 M 6 3 8 1 4 M 8 3 8 1 7 M M V Z M V Z M V Z M V Z M V Z M V Z M V Z 8 36 2 8M 8 36 31M 6 3b 34M 8 38 36M 8 38 4 3M 8 38 15M 8 3818M MVZ MVZ MVZ MVZ MVZ MVZ MVZ 63 6 2 9M 83 6 3 2M 3158 5M 83 6 39M 8 3 o 4 4M 6 3 0 i b M 83 819M Peromyscus m a n i c u l a t u s r u b i d u s MVZ 8 38 2 0M HVZ 03823M MVZ 8 38 2 6M MVZ 87651M MVZ 8 7613 3M MVZ 87656M MVZ 8 76 59M iMVZ 68 963 M MVZ 81517M MVZ 13335M MVZ 8 3A8 7M f iV Z 138850M iMVZ 3676M MVZ 9 7.996M MVZ A7726M MVZ 9 9A7 0M MVZ 125833M MVZ 128680M MVZ 28833M MVZ 136189M MVZ 136193M MVZ 136197M MVZ 8 382IM MVZ 8 38 2AM MVZ 8 38 2 7M MVZ 8 76A9M MVZ 8 76 5AM MVZ 8 76 5 7M MVZ 8 7660M MVZ 6 8 96AM MVZ 81518M MVZ 6 8 95AM MVZ 8 3A8 8M MVZ 138B51M MVZ 367 7M MVZ 9 799 7M MVZ 68 7 7 7M MVZ 99A71M MVZ 12583AM MVZ 28 8 3IM M V Z 2 88 38M MVZ 136191M MVZ 13619AM MVZ 83 82 2M MVZ 83 8 2 5M MVZ 87650M MVZ 8 7 65 2M MVZ 87 6 5 5M MVZ 8 76 5 8M MVZ 68 96 2M MVZ 81516M MVZ 13 33AM MVZ 68 9 5 3M MVZ 83A89M M,VZ 13U852M MVZ 3 86 3 2M MVZ 99A6 7M MVZ 9 9A6 9M MVZ 99A7 2M MVZ 128679M MVZ 28 83 2M MVZ 1361 88,-i MVZ 13 619 2 M MVZ 13 6196M P e r o m y s c u s m a n i c u l a t u s r u b i d u s ACKNOWLEDGMENTS I am p l e a s e d t o l i s t here the many persons who have a s s i s t e d me i n some way i n c a r r y i n g out t h i s s t u d y . My g r a t i t u d e goes t o the f o l l o w i n g v o l u n t e e r s who f o r the sake of adventure j o i n e d me on one or more of my e x p e d i t i o n s : F a b i a n Anderson, B r a d l e y Ven H u i z e n , Bruce Hepburn, W a l t e r Wogee, L a r r y Evans, and Dr. H. S t i c h and f a m i l y . I am sure a l l of those l i s t e d would j o i n me i n t h a n k i n g N. B r e a r l e y f o r t h e l o a n of h i s e x c e l l e n t t e n t . I am a l s o p l e a s e d t o thank Don Cookshank and the p r o p r i e t o r o f the P o r t Hardy B u i l d i n g Supply Company, b o t h of whom were of g r e a t h e l p t o me d u r i n g my s t a y s i n P o r t Hardy. I am i n debt t o Dr. M i l l e r f o r h e l i c o p t e r t r a n s p o r t a t i o n t o T r i a n g l e I s l a n d , as w e l l as the \" R o s a l i e 1\", \"Quest 2\", and the \" M a b r i s a \" a l l f i s h b o a t s t h a t have towed my b o a t t o the f u r t h e r p o i n t s of my range. The \" I s l a n d E x p r e s s \" t u g des e r v e s thanks f o r unknowingly t o w i n g our load e d boat 30 m i l e s one c o l d and foggy n i g h t , much t o t h e d i s c o m f o r t of my a s s i s t a n t Walt Wogee. Mr. T u l l y , Tony H o l l a n d , \"Zac the R u s s i a n \" , L a r r y and Annette K i l l e e n ; the crew of the \" M a b r i s a \" , and t h e P o r t Hardy B u i l d i n g Supply Company p r o p r i e t o r and h i s w i f e deserve s p e c i a l p r a i s e f o r the numerous meals t h a t were o f f e r e d and g r a t e f u l l y devoured. There were ti m e s when I c o n s i d e r e d t h a t my companion and I made s e r i o u s i n d e n t a t i o n s i n t o t h e f o o d s u p p l i e s of t h e s e k i n d p e o p l e ; t h e y w i l l never know how d e e p l y g r a t e f u l we were f o r t h e i r f r i e n d s h i p . An a c c i d e n t August 21, 1969, has l e f t me s h a m e f u l l y t h a n k f u l t o two ex-Newfoundland f i s h e r m e n whose names were not o b t a i n e d d u r i n g the c o n f u s i o n . These two men r e s c u e d my a s s i s t a n t at n i g h t d u r i n g a p e r i o d of rough weather and, d e s p i t e t h e i r f i s h i n g commitments, brought us t o the rescue v e s s e l M. V. Ready, where a t m i d n i g h t we were t r a n s f e r r e d f o r the f i n a l t r i p t o A l e r t Bay H o s p i t a l . The n u r s e s a t the h o s p i t a l have t o be commended f o r t h e i r u n d e r s t a n d i n g . The manager at t h e l o c a l bank, however, deserves w a t c h i n g f o r w i t h o u t any i d e n t i f i c a t i o n , I was a b l e to cash a check and i n so d o i n g a v o i d s t a r v i n g f o r the next few days, f o r t h i s I am v e r y much i n d e b t e d to him. My thanks must a l s o go t o Dr. ¥. Z. L i d i c k e r f o r the l o a n o f specimens from the Museum of V e r t e b r a t e Zoology, B e r k e l e y , a l s o t o Dr. J . B r i s t o l P o s t e r and C h a r l e s J . Guiguet f o r the l o a n o f specimens from the B r i t i s h Columbia P r o v i n c i a l Museum, V i c t o r i a . c My s i s t e r s , J a n e t who h e l p e d me w i t h the k a r y o t y p e s , and C a r o l y n who h e l p e d w i t h the m a n u s c r i p t p r e p a r a t i o n , deserve my a p p r e c i a t i o n . Thanks f o r t e c h n i c a l a d v i c e and comments are extended t o Dr. -Ti C. Hsu and Mrs. S t i c h . I am e s p e c i a l l y g r a t e f u l t o Dr. J . Mary T a y l o r , my s u p e r v i s o r , and t o the o t h e r members of my p a n e l ; Dr. I . McT. Cowan, Dr. G. Scudder, and Dr. H. S t i a l l of whom have guided and provided c r i t i c a l comment during t h i s study. F i n a n c i a l support of t h i s p r o j e c t was from an N.R.C. grant (A-3462) awarded to Dr. J . Mary T a y l o r . LITERATURE CITED ARAKAKI, D. T. and SPARKES. 1965a. Cytogenetics of Peromyscus maniculatus (Deer mouse). Mamm. Chromosome Newsletter, 18:150-151. 1965b. The Chromosomes of Peromyscus maniculatus h o l l e s t e r i . Mamm. Chromosome Newsletter 17:79 BANKS, R. C. 1967. The Peromyscus g u a r d i a - i n t e r p a r i e t a l i s comples. J . Mamm., 48:210-218 BENIRSCHKE, K. (Ed). 1969 Comparative Mammalian C y t o g e n e t i c s . S p r i n g e r - V e r l a g New York Inc. BENDELL, J . F. 1959. Food as a c o n t r o l of a p o p u l a t i o n of white - f o o t e d mice P. leucopus novebronacensis ( F i s c h e r ) . Canadian J . Zoo l . 37:173-209 BERRY, R. J . 1964. The E v o l u t i o n of an Is l a n d P o p u l a t i o n of the House mouse.Evolution 18:468-483 BLAIR, ¥. F. 1942. Systematic R e l a t i o n s h i p s of Peromyscus and s e v e r a l other R e l a t e d Genera as Shown by the Bacu l a r . J . Mamm. 23:196-204 1950. E c o l o g i c a l F a c t o r s i n S p e c i a t i o n of Peromyscus. E v o l u t i o n 4 253-275. 1951. P o p u l a t i o n s t r u c t u r e , s o c i a l b ehavior and environmental r e l a t i o n s i n a n a t u r a l p o p u l a t i o n of the Beach mouse (Peromyscus p o l i o n o t u s leucocephalus) C o n t r i b . Lab. V e r t . B i o l . U. of Mich. 48:41-47 BLAIR ¥. F. and ¥. E. HOWARD. 1944. Experimental evidence of sexual i s o l a t i o n between three forms of the cenospecies, Peromyscus maniculatus. C o n t r i b . Lab. V e r t . B i o l . U. of Much. 26:1-19 BOLE, B. P. 1939. The quadrat method of studying small mammal popu l a t i o n s S c i . Publ. Cleveland Mus. Nat. H i s t . 5:15-77 BRADSHAW, N. 1970. S e c t i o n of C e l l B i o l o g y , The U n i v e r s i t y of Texas, M. D. Anderson H o s p i t a l and Tumor I n s t i t u t e , ,... Houston, Texas. BRAND, L. R. and R. E. RYKMAN. 1968. La b o r a t o r y l i f e h i s t o r i e s of Peromyscus eremicus and Peromyscus i n t e r p a r i e t a l i s . V o l . 49 No. 3:495-501 BURT, W. H. 1932. D e s c r i p t i o n s of he r e t o f o r e unknown mammals from i s l a n d s i n the Qulf of C a l i f o r n i a , Mexico. Trans. San Diego Soc. Nat. H i s t . 7:161-182 CARL, C. G., C. J . GUIGUET, G. A. HARDY. 1950. B i o l o g y of the Scott I s l a n d group B r i t i s h Columbia. Report of the P r o v i n c i a l Museum of Natural H i s t o r y and Anthropology, pp.21-63 CHITTY, D. 1952. The n a t u r a l s e l e c t i o n of s e l f r e g u l a t o r y behavious i n animal p o p u l a t i o n s . Proc. E c o l . Soc. A u s t r a l i a 2:51-78 CLARK, P. H. 1941. C o r r e l a t i o n and body p r o p o r t i o n s i n mature mice of the genus Peromyscus. Genetics 26:283-300 COWAN, I . McT. 1935. A d i s t r i b u t i o n a l study of the Peromyscus s i t k e n s i s group of wh i t e - f o o t e d mice. U. C a l . P u b l . Z o o l . 40:429-438 COWAN, I. McT. and C. J . GUIGUET. 1965. The Mammals of B r i t i s h Columbia. B r i t i s h Columbia Prov. Mus. Handbook No. 11 pp.414 DARLINGTON, P. J . 1957. Zoogeography. John Wiley and Sons, Inc. pp 646. DAWSON, W. D. 1965. F e r t i l i t y and s i z e i n h e r i t a n c e i n a Peromyscus s p e c i e s c r o s s . E v o l u t i o n , 19:44-55 DELANY, M. J . 1961. The e c o l o g i c a l d i s t r i b u t i o n of small mammals i n Northwest Sc o t l a n d . Proc. Z o o l . Soc. London 137(1):107-126 DELANY, M. J . and I. R. BISHOP. I960. The syst e m a t i c s , l i f e h i s t o r y and e v o l u t i o n of the Bank vol e (Clethrionomys t i l e s i u s ) i n north-west S c o t l a n d . Proc. Z o o l . Soc. London. 13 5:409-422 DICE, L. R. 1932. V a r i a t i o n i n a geographic race of the deer-mouse, Peromyscus maniculatus b a i r d i i . Papers Mus. Z o o l . Univ. Mich., 239: 1-26 1933. F e r t i l i t y r e l a t i o n s h i p s between some of the species and subspecies of mice i n the genus Peromyscus. J . Mamm. 14:298-305 1939. V a r i a t i o n i n the Deer-mouse (Peromyscus maniculatus) i n the Columbia B a s i n i n southeastern Washington and adjacent Idaho and Oregon. C o n t r i b . Lab. V e r t . B i o l . Univ. Mich., 12: 1-22, 1 map. 1940a. E c o l o g i c and g e n e t i c v a r i a b i l i t y w i t h i n species of Peromyscus. Amer. Nat. V o l . LXXIV No. 752:212-221 1940b. S p e c i a t i o n i n Peromyscus. Amer. Nat. 74:289-298 1941a. V a r i a t i o n i n the Deer-mouse, Peromyscus maniculatus, i n p a r t s of Oregon, C a l i f o r n i a and Baja , C a l i f o r n i a , C o n t r i b . Lab. V e r t . Genetics, 18: 1-11 1941b. Methods f o r e s t i m a t i n g p o p u l a t i o n s of mammals. J . W i l d l i f e Mgt. 5:398-407 1949. V a r i a t i o n of Peromyscus maniculatus i n p a r t s of western Washington and adjacent Oregon. C o n t r i b . Lab. V e r t . B i o l . Univ. Mich. 44:1-34 1968. In KING, J . A. (ed.) B i o l o g y of Peromyscus (Rodentia) S p e c i a l p u b l i c a t i o n No. 2. The American of Mammalogists. pp 75-94 DICE, L. R. and H. J . LERAAS. 1936. A graphic method f o r comparing s e v e r a l sets of measurements. C o n t r i b . Lab. V e r t . Gen. Univ. Mich. 3:1-3 FORD, C. E. and J . L. HAMERTON. 1956. A C o l c h i c i n e , Hypotonic c i t r a t e , Squash Sequence f o r Mammalian Chromosomes. S t a i n Technol. 31:247-254. FOSTER, J . B. 1965. The E v o l u t i o n of The Mammals of the Queen C h a r l o t t e I s l a n d s , B r i t i s h Columbia. Occ. Papers of the B r i t i s h Columbia Prov. Mus. GUIGUET, C. J . 1955. Undescribed mammals from the i s l a n d s of B r i t i s h Columbia. Rept. Prov. Mus. Nat. H i s t , and Anthro., B r i t i s h Columbia, f o r 1954. HALL, E. R. 1938. V a r i a t i o n Among I n s u l a r Mammals of Georgia S t r a i t , B r i t i s h Columbia. Amer. Nat. V o l LXXII No. 742:453-463 HALL, E. R. and K. R. KELSON. 1959. The Mammals of North America. Ronald Press Co., N. Y. Peromyscus, 2: v i i i , 547-1083 HOFFMEISTER, D,. F. 1951. A taxonomic and E v o l u t i o n a r y Study of the Pinon Mouse, Peronyscus t r u e i . I l l i n o i s B i o . Monographs, V o l . XXI, No. 4 HOOPER, E. T. 1958. The male p h a l l u s i n mice of the genus Peromyscus. Misc. Publ. Mus. Z o o l . Univ. Mich. 105:1-24 1959. The glans penis i n f i v e genera of C r i c e t i d rodents. Occ. Pap. Mus. Z o o l . Univ. Mich. 613:1-10 HOOPER, E. T. and G. G. MUSSER. 1964. Notes on c l a s s i f i c a t i o n of the rodent genus Peromyscus. Occ. Pap. Mus. Z o o l . Univ. Mich. 63 5:1-24 HORNER, B. E. 1954. A r b o r e a l adaptations of Peromyscus with s p e c i a l r e f e r e n c e to the use of the t a i l . Contr. Lab. V e r t . B i o l . Univ. Mich. 61:1-85 HORNER, B. E., J . M. TAILOR, and H. PADYKULA. 1965. Pood h a b i t s and g a s t r i c morphology of the grasshopper mouse. J . Mamm. V o l 45, 4:513-535 HSU, T. C. (ed) 1969. Mammalian Chromosome Newsletter. M. D. Anderson H o s p i t a l p u b l i c a t i o n , pp. 65-132 HSU, T. C. and P. E. ARRIGHI. 1966. Chromosomal E v o l u t i o n i n s t h e Genus Peromyscus. Cytogenetics 5(5):355-359 • 1968. Chromosomes of Peromyscus. 1. E v o l u t i o n a r y Trends i n 20' s p e c i e s . Cytogenetics 7:417-446 KING, J . A. (ed). 1968. B i o l o g y of Peromyscus (Rodentia) S p e c i a l P u b l i c a t i o n No. 2. The American S o c i e t y of Mammalogists. 587pp. KREBS, C. 1970. Microtus p o p u l a t i o n b i o l o g y : B e h a v i o r a l changes a s s o c i a t e d w i t h the p o p u l a t i o n c y c l e i n M.ochrogastor and M. pennsylvanicus. Ecology V o l . 51 1:34-52 KREIZINGER, J . and M. ¥. SHAW. 1970. Chromosomes of Peromyscus. I I . The Y Chromosome of Peromyscus maniculatus. Cytogenetics 9:52-72 KRAJINA, V. J . (ed) 1969. Ecology of Western North America. Dept. of Botany, Univ. of B r i t i s h Columbia, pp.146. LAWLOR, T. E. '1971. E v o l u t i o n of Peromyscus on northern i s l a n d s i n the Gulf of C a l i f o r n i a , Mexico. Trans. San Diego Soc. of N a t u r a l H i s t o r y , V o l . 16, 5:91-124 LACK, D. 1947. Darwin's Pinches. Cambridge U n i v e r s i t y P r e s s . 1969. Comments made during Symposium on Adaptive Aspects of I n s u l a r E v o l u t i o n , Mayaguez, Puerto R i c o . LERNER, I. M. 1954. Genetic Homeostasis Edinburgh, O l i v e r and Boyd Press 134pp MAYR, E,, E. G. LINSEY, and R. L. USINGER. 1953. Methods and P r i n c i p l e s of Sytematic Zoology. McGraw H i l l Co., N. Y. 328pp. MACARTHUS, R. H. and E. 0. WILSON. 1967. The Theory of I s l a n d Biogeography, P r i n c e t o n U n i v e r s i t y P r e s s , pp 203 McCABE, T. T. and I. McT. COWAN. 1945. Peromyscus maniculatus Macrorhinus aiid the Problem of I n s u l a r i t y . Trans. Royal Can.- I n s t . , V o l . 25, No. 54:117-212 MOORE, R. E. 1965. O l f a c t o r y d i s c r i m i n a t i o n as an i s o l a t i n g mechanism between Peromyscus maniculatus and Peromyscus p o l i o n o t u s . Amer. Midland Nat. 73:85-100 NADLER, C. R..1968. The Chromosomes pf Spermophilus townsendi and r e p o r t of a new subspecies. Cytogenetics 7:144-157 OHNO, S., C. WEILER; J . POOLE; L. CHRISTIAN and C. STENIUS. 1966.: Autosomal Polymorphism due to P e r i c e n t r i c I n v e r s i o n s i n the Deer mouse (Peromyscus maniculatus) and some Evidence of Somatic Segregation. Chromosoma, 18:177-187 OSGOOD, W. H. 1901. N a t u r a l h i s t o r y of the Queen C h a r l o t t e I s l a n d s , B r i t i s h Columbia. N a t u r a l h i s t o r y of the Cook I n l e t r e g i o n , A l a s k a . North Amer. Fauna 21:1-87 1909. R e v i s i o n of the mice of the American genus Peromyscus. North American Fauna 28:1-285 ORLOV, V. N. 1970. E v o l u t i o n a r y aspects of chromosomal d i f f e r e n t i a t i o n i n mammals. Z o o l . Zhurn. 49:813-830 RICKETTS, E. F. and J . CALVIN. 1948. Between P a c i f i c T i d e s . S t a n f o r d Univ. P r e s s , S t a n f o r d , C a l i f . 365pp. ROOD, J . P. 1.966. Observations on the r e p r o d u c t i o n of Peromyscus oreas and P. maniculatus. Proc. Am. P h i l . Soc. 105:421-426 SINGH, R. P. and D. B. McMILLAN. 1966. Karyotypes of Three Subspecies of Peromyscus. J . Mamm.. 47:261-265 SUMNER, F. B.. 1918. Continuous and di s c o n t i n u o u s v a r i a t i o n s and t h e i r i n h e r i t a n c e i n Peromyscus. American Nat. 177-208, 290-301 and 439-454. ' 1926. Continuous and discontinuous v a r i a t i o n i n mice of the Peromyscus pOlionotus group from F l o r i d a and Alabama. J . Mamm., 7:149-184 SMITH, J . D. 1970. Personal communication. C a l i f . State C o l l e g e , F u l l e r t o n , C a l i f . TAYLOR, J . M. The U n i v e r s i t y of B r i t i s h Columbia, Dept. of Zoology THOMAS, B. 1968. Karyotypes of Some Western Species of Peromyscus. M. A. Thesis C a l . State College at F u l l e r t o n . pp.41 1970. Chromosome Polymorphism i n an I s l a n d P o p u l a t i o n of Peromyscus maniculatus. Mammalian Chromosome Newsletter, V o l . 11 No. 1:24-25, 2 p l a t e s V0R0NTS0V, N. N. 1957. S t r u c t u r e of the stomach and r e l a t i v e development of p a r t s of the i n t e s t i n e i n C r i c e t i n a e (Rodentia, Mammalia) of the P a l e a r c t i c and the New World. A t r a n s l a t i o n of Doklady Akad. Nauk 117:526-529 WILSON, E. 0. and W. L. BROWN, J r . 1953. The subspecies concept and i t s taxonomic a p p l i c a t i o n . Syst. Z o o l . 2:97-111 WHITE, M. J . D., R. E. BLACKITH; R. M. BLACKITH; and J . CHENEY. 1967. Cytogenetics of the V i a t i c a group of Morabine. Grasshoppers. I. The C o a s t a l Species. A u s t r a l i a n J . Zool. 15:263-302. "@en ; edm:hasType "Thesis/Dissertation"@en ; edm:isShownAt "10.14288/1.0101826"@en ; dcterms:language "eng"@en ; ns0:degreeDiscipline "Zoology"@en ; edm:provider "Vancouver : University of British Columbia Library"@en ; dcterms:publisher "University of British Columbia"@en ; dcterms:rights "For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use."@en ; ns0:scholarLevel "Graduate"@en ; dcterms:title "Evolutionary relationships among Peromyscus from the Georgia Strait, Gordon, Goletas, and Scott Islands of British Columbia, Canada"@en ; dcterms:type "Text"@en ; ns0:identifierURI "http://hdl.handle.net/2429/33965"@en .