Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Activity measures of free-ranging grizzly bears (Ursus arctos) in the Flathead drainage 1991

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata

Download

Media
UBC_1991_A6_7 M32.pdf
UBC_1991_A6_7 M32.pdf [ 6.01MB ]
UBC_1991_A6_7 M32.pdf
Metadata
JSON: 1.0098597.json
JSON-LD: 1.0098597+ld.json
RDF/XML (Pretty): 1.0098597.xml
RDF/JSON: 1.0098597+rdf.json
Turtle: 1.0098597+rdf-turtle.txt
N-Triples: 1.0098597+rdf-ntriples.txt
Citation
1.0098597.ris

Full Text

A C T I V I T Y MEASURES OF F R E E - R A N G I N G G R I Z Z L Y BEARS ( U r s u s a r c t o s ) I N T H E F L A T H E A D DRAINAGE b y ROBERT K E I T H MCCANN B . S c , 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 , 1985 A T H E S I S S U B M I T T E D I N P A R T I A L F U L F I L M E N T OF T H E REQUIREMENTS FOR THE DEGREE OF MASTER OF S C I E N C E i n T H E F A C U L T Y OF GRADUATE S T U D I E S ( D e p a r t m e n t o f A n i m a l S c i e n c e ) We a c c e p t t h i s t h e s i s a s c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d T H E U N I V E R S I T Y OF B R I T I S H COLUMBIA A p r i l 1991 © R o b e r t K e i t h M c C a n n , 1991 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of AWVAAV^ <X_AtLUC£- The University of British Columbia Vancouver, Canada D a t e Apcuu a°\ m i DE-6 (2/88) A B S T R A C T B e t w e e n 1984 a n d 1 9 8 8 , 4756 h o u r s o f a c t i v i t y d a t a w e r e c o l l e c t e d o n 15 d i f f e r e n t g r i z z l y b e a r s ( U r s u s a r c t o s ) i n t h e F l a t h e a d d r a i n a g e o f s o u t h e a s t e r n B r i t i s h C o l u m b i a a n d a d j a c e n t p o r t i o n s o f M o n t a n a . D a t a w e r e c o l l e c t e d w i t h t h e a i d o f p o r t a b l e c h a r t r e c o r d e r s t h a t r e c o r d e d t h e o u t p u t f r o m m o t i o n - s e n s i t i v e r a d i o c o l l a r s . W h i l e many b e n e f i t s s t e m f r o m r e m o t e s e n s i n g o f a s t u d y a n i m a l a s i n t r a c t a b l e a s t h e g r i z z l y , b o t h t h e m e t h o d o f d a t a c o l l e c t i o n a n d t h e a s s u m p t i o n s e m p l o y e d i n t r a n s l a t i n g c h a r t r e c o r d i n g s i n t o q u a n t i t a t i v e m e a s u r e s o f b e a r a c t i v i t y may a f f e c t c o n c l u s i o n s d r a w n . M a j o r o b j e c t i v e s o f t h i s s t u d y w e r e : 1) t o a s s e s s t h e v a l i d i t y o f p r o c e d u r e s e m p l o y e d t o t r a n s l a t e c o n t i n u o u s c h a r t r e c o r d i n g s o f s i g n a l p a t t e r n s f r o m m o t i o n - s e n s i t i v e r a d i o c o l l a r s i n t o q u a n t i t a t i v e m e a s u r e s o f b e a r a c t i v i t y ; 2) t o a s s e s s w h e t h e r a c t i v e a n d i n a c t i v e b o u t l e n g t h s w e r e r e l a t e d t o s e x a n d a g e r e l a t e d d i f f e r e n c e s i n e n e r g e t i c r e q u i r e m e n t s a n d s e a s o n a l d i f f e r e n c e s i n f o o d t y p e ; a n d 3) t o d o c u m e n t a c t i v i t y b u d g e t s a n d p a t t e r n s a s f u n c t i o n s o f s e x , a g e , s e a s o n , a n d t h e d a i l y s o l a r c y c l e . I n t h e a b s e n c e o f c o n c u r r e n t v i s u a l o b s e r v a t i o n s o f g r i z z l y b e a r s a n d r e c o r d e d s i g n a l p a t t e r n s , t h e v a l i d i t y o f p r o c e d u r e s u s e d t o i n t e r p r e t c h a r t r e c o r d i n g s was a s s e s s e d b y e s t i m a t i n g p e r c e n t o f t i m e a c t i v e (%TA) u n d e r v a r y i n g d e f i n i t i o n s o f a c t i v e a n d i n a c t i v e b o u t s , a n d b y c o m p a r i n g %TA t o v a l u e s f o u n d b y o t h e r r e s e a r c h e r s . E s t i m a t e s o f %TA w e r e i i i s t a b l e over the range o f a c t i v i t y bout d e f i n i t i o n s examined. S t a b i l i t y r e s u l t e d from bears spending most o f t h e i r time i n a c t i v e and i n a c t i v e bouts > 30 min d u r a t i o n . E s t i m a t e s of %TA f o r t h i s study agreed w i t h r e s u l t s on o t h e r p o p u l a t i o n s . Over the non-denning p o r t i o n of the year, g r i z z l y bears were a c t i v e about 55% o f the time. A n a l y s e s of bout d u r a t i o n s were plagued by a b i a s a g a i n s t a c t i v e bouts t o be monitored i n t h e i r e n t i r e t y , because when a c t i v e , bears f r e q u e n t l y moved out o f range of the c h a r t r e c o r d e r . The d i s t r i b u t i o n o f a c t i v i t y over the 24-hour c y c l e d i f f e r e d from many o t h e r s t u d i e s i n t h a t bears i n t h e F l a t h e a d were a c t i v e mostly i n d a y l i g h t hours. A g r e a t e r use o f darkness by bears i n the f a l l , compared t o o t h e r seasons, may be r e l a t e d t o a v a i l a b l e d a y l i g h t o r t o avoidance o f hunters. While a c t i v i t y p a t t e r n s were g e n e r a l l y bimodal w i t h a c t i v i t y peaks i n morning and evening, the morning a c t i v i t y peak was not s t r o n g l y t i e d t o s u n r i s e . A c t i v i t y i n the morning g e n e r a l l y reached a peak 1 or more hours a f t e r s u n r i s e . Seasonal t r e n d s i n a c t i v i t y budgets conformed t o p h y s i o l o g i c a l changes i n bears n e c e s s i t a t e d by requirements f o r denning. S i g n i f i c a n t i n d i v i d u a l v a r i a t i o n e x i s t s i n both a c t i v i t y p a t t e r n s and budgets, and may be r e l a t e d t o body s i z e , t o frequency dependent f o r a g i n g s t r a t e g i e s , o r t o d i f f e r i n g c o m p e t i t i v e a b i l i t y f o r defendable r e s o u r c e s among sex-age c l a s s e s o f bears. 1 i v T A B L E OF CONTENTS P a g e A B S T R A C T i i T A B L E OF CONTENTS i v L I S T OF T A B L E S v i L I S T OF F I G U R E S v i i i L I S T OF A P P E N D I C E S x i i ACKNOWLEDGEMENTS x i i i C H A P T E R 1: AN OVERVIEW i ) G E N E R A L INTRODUCTION 1 i i ) STUDY A R E A 4 i i i ) F I E L D PROCEDURES 6 i v ) D I S T R I B U T I O N OF DATA 8 V) L I T E R A T U R E C I T E D 12 C H A P T E R 2: A S S E S S I N G A C T I V I T Y FROM CHART RECORDINGS i ) INTRODUCTION 15 i i ) METHODS 20 C h a r t I n t e r p r e t a t i o n 20 S t a b i l i t y o f A c t i v i t y E s t i m a t e s 28 S t a t i s t i c a l A n a l y s e s 30 i i i ) R E S U L T S AND D I S C U S S I O N 31 i v ) CONCLUSIONS 42 V) L I T E R A T U R E C I T E D 45 C H A P T E R 3 : BOUT LENGTHS i ) INTRODUCTION 48 i i ) METHODS 54 A n a l y s e s W i t h i n S e a s o n s 54 V Annual and Among Seasons Ana l y s e s 56 i i i ) RESULTS 57 Annual and Seasonal Trends 59 Analy s e s W i t h i n Seasons 59 i v ) DISCUSSION 65 V) LITERATURE CITED 71 CHAPTER 4: ACTIVITY BUDGETS AND PATTERNS i ) INTRODUCTION 74 i i ) METHODS 77 Comparisons of A c t i v i t y P a t t e r n s 78 Comparisons of A c t i v i t y Budgets 79 i i i ) RESULTS 80 A c t i v i t y P a t t e r n s 80 A c t i v i t y Budgets 85 i v ) DISCUSSION 94 A c t i v i t y P a t t e r n s 96 A c t i v i t y Budgets 103 V) LITERATURE CITED 109 CHAPTER 5: OVERALL CONCLUSIONS 113 APPENDIX 115 v i LIST OF TABLES Page Ta b l e 1. D i s t r i b u t i o n of r e c o r d e d data (sum of a c t i v e and i n a c t i v e bout d u r a t i o n s ) by p o p u l a t i o n component and month f o r 1984 through 1988 combined, i n decimal hours. Number of bears i n each monthly sample are i n b r a c k e t s . .... T a b l e 2 D i s t r i b u t i o n of r e c o r d e d data (sum o f a c t i v e and i n a c t i v e bout d u r a t i o n s ) by p o p u l a t i o n component and season f o r 1984 through 1988 combined, i n decimal hours. Number o f bears i n each seasonal sample are i n b r a c k e t s . T a b l e 3. Means, standard e r r o r s of the means, and ranges of p e r c e n t o f time a c t i v e by sex-age c l a s s , and o v e r a l l , c a l c u l a t e d from complete 24-hour samples on g r i z z l y bears T a b l e 4. Means, standard e r r o r s o f the means, and ranges o f p e r c e n t o f time a c t i v e by month, c a l c u l a t e d from complete 24-hour samples on g r i z z l y bears 10 11 34 37 T a b l e 5. Percent of time a c t i v e by p o p u l a t i o n component and season as determined by complete a c t i v e and i n a c t i v e bouts (columns under C) and as determined by a l l a v a i l a b l e data (columns under A ) . Samples s i z e s of complete bouts are i n b r a c k e t s 58 T a b l e 6. T a b l e 7. T a b l e 8. T e s t s o f nonparametric m u l t i p l e c o n t r a s t s f o r d u r a t i o n s o f complete i n a c t i v e bouts w i t h i n seasons. Values are t e s t s t a t i s t i c s (value of c o n t r a s t d i v i d e d by i t s s t a n d a r d e r r o r ) T e s t s o f nonparametric m u l t i p l e c o n t r a s t s f o r d u r a t i o n s o f complete a c t i v e bouts w i t h i n seasons. Values are t e s t s t a t i s t i c s (value o f c o n t r a s t d i v i d e d by i t s standard e r r o r ) Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e of a c t i v i t y p a t t e r n s f o r g r i z z l y bears over seasons. SA C l a s s r e p r e s e n t s those sex- age c l a s s e s (subadult males, s u b a d u l t females, a d u l t females) f o r which t h e r e were s u f f i c i e n t d a t a t o t e s t 62 63 81 T a b l e 9. Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e o f a c t i v i t y p a t t e r n s f o r sex-age v i i c l a s s e s o f g r i z z l y bears over e a r l y summer and the b e r r y season 84 Ta b l e 10. Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e o f a c t i v i t y budgets f o r g r i z z l y bears over seasons. SA C l a s s r e p r e s e n t s those sex- age c l a s s e s (subadult males, s u b a d u l t females, a d u l t females) f o r which t h e r e were s u f f i c i e n t d a t a t o t e s t 88 Ta b l e 11. Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e o f a c t i v i t y budgets f o r sex-age c l a s s e s o f g r i z z l y bears over e a r l y summer and t h e b e r r y season 93 v i i i LIST OF FIGURES Page F i g u r e 1. T y p i c a l p u l s e mode p a t t e r n s o b t a i n e d from bears wearing 2.5-min r e s e t d e l a y c o l l a r s , a) A c t i v e p u l s e modes i n t e r s p e r s e d w i t h b r i e f i n a c t i v e p u l s e modes (marked by arrows), and b) i n a c t i v e p u l s e modes i n t e r s p e r s e d w i t h a c t i v e p u l s e modes o f approximately the 2.5-min r e s e t d e l a y p e r i o d . One i n c h o f c h a r t t r a c e r e p r e s e n t s about 4 min 23 F i g u r e 2. Examples o f assignment o f a c t i v i t y bouts (upper continuous l i n e ) t o p u l s e mode p a t t e r n s (lower broken s e r i e s ) o b t a i n e d from bears wearing 2.5- min r e s e t d e l a y c o l l a r s . Read from l e f t t o r i g h t : U = unknown bout; A = a c t i v e bout (as measured when f o l l o w i n g bout i s unknown); I = i n a c t i v e bout (note a d d i t i o n o f 2.5 min c o r r e c t i o n ) ; A = a c t i v e bout (note s u b t r a c t i o n of 2.5 min when f o l l o w i n g bout i s i n a c t i v e ) ; I = i n a c t i v e bout; A = a c t i v e bout. One i n c h of c h a r t t r a c e r e p r e s e n t s about 4 min 24 F i g u r e 3. T y p i c a l p u l s e mode p a t t e r n s o b t a i n e d from bears wearing 5-s r e s e t d e l a y c o l l a r s , a) A c t i v e p u l s e mode p a t t e r n showing f r e q u e n t s w i t c h i n g between a c t i v e and i n a c t i v e p u l s e s , and b) a l t e r n a t i n g a c t i v e and i n a c t i v e ( s o l i d lower t r a c e ) p u l s e mode p a t t e r n s . One i n c h o f c h a r t t r a c e r e p r e s e n t s about 4 min 26 F i g u r e 4. Examples of assignment o f a c t i v i t y bouts (upper continuous l i n e ) t o p u l s e mode p a t t e r n s (lower broken s e r i e s ) o b t a i n e d from bears wearing 5-s r e s e t d e l a y c o l l a r s . Read from l e f t t o r i g h t : I = i n a c t i v e bout; U = unknown bout (note t h e i n c l u s i o n o f p u l s e mode p a t t e r n s t oo s h o r t t o c l a s s i f y a t e i t h e r end o f the unknown b o u t ) ; A = a c t i v e bout (note i n a c t i v e p u l s e mode p a t t e r n s w i t h d u r a t i o n s < 2.5 min); I = i n a c t i v e bout (note a c t i v e p u l s e mode p a t t e r n s w i t h d u r a t i o n s < 1 min); A = a c t i v e bout. One i n c h of c h a r t t r a c e r e p r e s e n t s about 4 min 27 F i g u r e 5. a) Percent o f t o t a l a c t i v e time as d i s t r i b u t e d between a c t i v e bouts of d i f f e r e n t d u r a t i o n s and seasons, and b) pe r c e n t o f t o t a l i n a c t i v e time as d i s t r i b u t e d between i n a c t i v e bouts o f d i f f e r e n t d u r a t i o n s and seasons 33 i x F i g u r e 6. Percent of time a c t i v e by month f o r a) a d u l t males, b ) a d u l t females, c) s u b a d u l t males, and d) su b a d u l t females as c a l c u l a t e d from a l l data 36 F i g u r e 7. Annual p e r c e n t o f time a c t i v e by hour o f the day f o r a) a d u l t males, b) a d u l t females, c) subad u l t males, and d) suba d u l t females. For hours of the day, 1 = 0000-0100; 2 = 0100- 0200 e t c 38 F i g u r e 8 F i g u r e 9, Annual p e r c e n t o f time a c t i v e by d i e l p e r i o d f o r a) a d u l t males, b) a d u l t females, c) s u b a d u l t males, and d) subadult females 40 Notched box p l o t s of complete a) a c t i v e , and b) i n a c t i v e , bout d u r a t i o n s p o o l e d a c r o s s seasons, f o r s u b a d u l t females, a d u l t females, s u b a d u l t males, and a d u l t males. Outside v a l u e s were omitted t o emphasize notches about the medians. For any 2 boxes w i t h notches about t h e medians t h a t do not o v e r l a p , the 2 medians 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 approximately a 95% c o n f i d e n c e l e v e l 60 F i g u r e 10. Notched box p l o t s o f complete a) a c t i v e , and b) i n a c t i v e , bout d u r a t i o n s p o o l e d a c r o s s sex-age c l a s s e s , f o r s p r i n g (SP), e a r l y summer (ES), b e r r y season (BS), and f a l l (FA). Outs i d e v a l u e s were omitted t o emphasize notches about the medians. For any 2 boxes w i t h notches about t h e medians t h a t do not o v e r l a p , t h e 2 medians 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 approximately a 95% c o n f i d e n c e l e v e l F i g u r e 11. F i r s t o r d e r i n t e r a c t i o n between seasons and d i e l p e r i o d s from A n a l y s i s o f V a r i a n c e o f g r i z z l y bear a c t i v i t y p a t t e r n s over seasons (Table 7 ) . P l o t t e d v a l u e s are p r e d i c t e d c e l l means F i g u r e 12. F i r s t o r d e r i n t e r a c t i o n between age c l a s s e s and d i e l p e r i o d s from A n a l y s i s o f V a r i a n c e of g r i z z l y bear a c t i v i t y p a t t e r n s f o r sex-age c l a s s e s over e a r l y summer and the b e r r y season (Table 8 ) . P l o t t e d v a l u e s are p r e d i c t e d c e l l means F i g u r e 13. Second o r d e r i n t e r a c t i o n between seasons, sex c l a s s e s , and d i e l p e r i o d s from A n a l y s i s o f V a r i a n c e o f g r i z z l y bear a c t i v i t y p a t t e r n s f o r sex-age c l a s s e s over e a r l y summer and the b e r r y season (Table 8 ) . Sex x d i e l p e r i o d i n t e r a c t i o n s are p l o t t e d f o r a) e a r l y summer, 61 83 86 X F i g u r e 14 F i g u r e 15, F i g u r e 16, F i g u r e 17, F i g u r e 18, F i g u r e 19, F i g u r e 20, and b) the b e r r y season, p r e d i c t e d c e l l means. P l o t t e d v a l u e s are 87 F i r s t o r d e r i n t e r a c t i o n between seasons and q u a r t e r day p e r i o d s from A n a l y s i s o f V a r i a n c e of g r i z z l y bear a c t i v i t y budgets over seasons (Table 9 ) . P l o t t e d v a l u e s a r e p r e d i c t e d c e l l means 90 Second o r d e r i n t e r a c t i o n between seasons, SA c l a s s e s , and q u a r t e r day p e r i o d s from A n a l y s i s of V a r i a n c e o f g r i z z l y bear a c t i v i t y budgets over seasons (Table 9 ) . SA c l a s s x d i e l p e r i o d i n t e r a c t i o n s are p l o t t e d f o r a) s p r i n g , b) e a r l y summer, c) the b e r r y season, and d) f a l l . P l o t t e d v a l u e s are p r e d i c t e d c e l l means 91 F i r s t o r d e r i n t e r a c t i o n between age c l a s s e s and q u a r t e r day p e r i o d s from A n a l y s i s o f V a r i a n c e of g r i z z l y bear a c t i v i t y budgets f o r sex-age c l a s s e s over e a r l y summer and t h e b e r r y season (Table 10). P l o t t e d v a l u e s are p r e d i c t e d c e l l means 95 Percent of time a c t i v e by hour o f the day i n s p r i n g f o r a) subadult females, b) a d u l t females, and c) subadult males. Arrows i n d i c a t e approximate times o f s u n r i s e and sunset. P l o t s were composed from a l l s p r i n g d a t a c o l l e c t e d . For hours o f the day, 1 = 0000-0100; 2 = 0100-0200 e t c 98 Percent o f time a c t i v e by hour of the day i n e a r l y summer f o r a) subadult females, b) a d u l t females, c) subadult males, and d) a d u l t males. Arrows i n d i c a t e approximate times o f s u n r i s e and sunset. P l o t s were composed from a l l e a r l y summer data c o l l e c t e d . For hours o f the day, 1 = 0000-0100; 2 = 0100-0200 e t c Percent of time a c t i v e by hour of the day i n the b e r r y season f o r a) s u b a d u l t females, b) a d u l t females, c) s u b a d u l t males, and d) a d u l t males. Arrows i n d i c a t e approximate times of s u n r i s e and sunset. P l o t s were composed from a l l b e r r y season data c o l l e c t e d . For hours o f the day, 1 = 0000-0100; 2 = 0100-0200 e t c Percent o f time a c t i v e by hour o f the day i n f a l l f o r a) subadult females, b) a d u l t females, and c) subadult males. Arrows i n d i c a t e approximate times of s u n r i s e and sunset. P l o t s were composed from a l l f a l l 99 100 x i d a t a c o l l e c t e d . F o r h o u r s o f t h e d a y , 1 = 0 0 0 0 - 0 1 0 0 ; 2 = 0 1 0 0 - 0 2 0 0 e t c 101 x i i L I S T OF A P P E N D I C E S P a g e A p p e n d i x 1 . D a t a t o t a l s (sum o f a c t i v e a n d i n a c t i v e b o u t d u r a t i o n s ) b y b e a r , y e a r , a n d s e a s o n , i n d e c i m a l h o u r s 115 x i i i ACKNOWLEDGEMENTS Many people have made c o n t r i b u t i o n s t o t h i s p r o j e c t - I can o n l y thank a few e x p l i c i t l y . F i r s t , I thank Dr. D. M. Shackleton, my s u p e r v i s o r , f o r the o p p o r t u n i t y t o do t h i s study and f o r h i s h e l p f u l i n s i g h t s . S p e c i a l thanks goes t o Dr. Bruce N. M c L e l l a n who f i r s t suggested the study t o p i c , p r o v i d e d v a l u a b l e a d v i c e and e x p e r t i s e on a l l a s p e c t s o f the r e s e a r c h , and c o l l e c t e d some o f the da t a used i n t h i s p r o j e c t . Bruce, and h i s w i f e , C e l i n e Doyon, a l s o made a v a i l a b l e an e x c e l l e n t f i e l d camp. A d d i t i o n a l l o g i s t i c a l support came from Dr. C h r i s Servheen of the U.S. F i s h and W i l d l i f e S e r v i c e and Ray DeMarchi o f the B.C. W i l d l i f e Branch. Dan Carney a r r i v e d i n t he f i e l d a t s e v e r a l opportune times and p r o v i d e d t i m e l y a d v i c e , good s t o r i e s and an o c c a s i o n a l chew. Tom Radandt he l p e d w i t h some of the f i e l d work i n 1988. Dr. M. G r i e g and S. K i t a o f the U.B.C. Computing Center, and Dr. Ray Peterson a l l p r o v i d e d s t a t i s t i c a l a d v i c e a t v a r i o u s stages o f the p r o j e c t . D i s c u s s i o n s w i t h F. W. Hovey and F. L. B u n n e l l c o n t r i b u t e d t o some o f the approaches used. 1 CHAPTER 1: AN OVERVIEW GENERAL INTRODUCTION C o n t i n u i n g expansion o f human p u r s u i t s i n t o the range o f the g r i z z l y bear (Ursus a r c t o s ) i n d i c a t e s t h a t c o n t i n u e d s u r v i v a l o f many g r i z z l y p o p u l a t i o n s w i l l depend on the a b i l i t y o f humans and bears t o c o e x i s t . S t u d i e s on g r i z z l y p o p u l a t i o n s i n environments t h a t have a h i g h l e v e l o f human i n t r u s i o n such as Yellowstone N a t i o n a l Park and European game r e s e r v e s , suggest t h a t bears are capable o f m o d i f y i n g t h e i r b e h a v i o r not o n l y t o a v o i d areas o f p r e d i c t a b l e human use but t o take advantage of times when d i s t u r b a n c e from humans i s low. Whether such m o d i f i c a t i o n o f b e h a v i o r towards g r e a t e r a c t i v i t y d u r i n g the hours o f darkness impinges on f o r a g i n g e f f i c i e n c y and e f f e c t i v e l y lowers the c a r r y i n g c a p a c i t y o f the environment i s u n c l e a r . C u r r e n t l y , t h e r e i s a need f o r g r e a t e r understanding o f when and how bears modify t h e i r b e h a v i o r t o a v o i d c o n t a c t w i t h humans, and how o t h e r f a c t o r s such as sex, age, and time o f yea r a f f e c t both the amount and s c h e d u l i n g o f a c t i v i t y . U l t i m a t e l y , the r e l a t i o n s h i p between b e h a v i o r and p o p u l a t i o n demography needs t o be determined. The i n f l u e n c e o f human p r e d a t i o n on a s p e c i e s w i t h low r e p r o d u c t i v e p o t e n t i a l such as the g r i z z l y (Bunnell and T a i t 1981) i s obvious. Of l e s s c e r t a i n t y i s the a d a p t a b i l i t y o f the g r i z z l y t o h a b i t a t m o d i f i c a t i o n s (Knight 1980). The s p e c i e s i s g e n e r a l l y regarded as h i g h l y v e r s a t i l e , as i s 2 demonstrated by i t s e x t e n s i v e h i s t o r i c a l range, s o l i t a r y s o c i a l system, omnivorous food h a b i t s , and g r e a t m o b i l i t y (Knight 1980). However, the be a r s ' s u r v i v a l depends on access t o a v a r i e t y o f h a b i t a t s w i t h i n a g i v e n annual c y c l e , and an even g r e a t e r v a r i e t y over a l i f e c y c l e , t o a l l e v i a t e s t o c h a s t i c a l l y o c c u r r i n g f a i l u r e s i n food r e s o u r c e s . Of equal u n c e r t a i n t y i s whether t h e presence o f human a c t i v i t y imposes a c o s t i n terms of reduced r e p r o d u c t i v e f i t n e s s through a l t e r a t i o n o f b e h a v i o r p a t t e r n s T h i s q u e s t i o n i s a c o n t e n t i o u s i s s u e f o r many s p e c i e s due t o the d i f f i c u l t y i n l i n k i n g d i s r u p t i o n o f be h a v i o r t o demographic consequences (Shank 1979). In g e n e r a l , d e t r i m e n t a l demographic e f f e c t s c o u l d a r i s e from 2 broad sources; e x c l u s i o n from c r i t i c a l h a b i t a t s , o r a l t e r e d a c t i v i t y budgets r e s u l t i n g i n a lowered net energy s t a t u s . Many s t u d i e s have demonstrated b e h a v i o r a l responses by w i l d l i f e s p e c i e s t o human a c t i v i t y (e.g., s p a t i a l d i s t r i b u t i o n s , A r c h i b a l d e t a l . 1987; f l i g h t responses, C h u r c h i l l 1982;) or p h y s i o l o g i c a l responses (e.g., c a r d i a c r a t e s , MacArthur e t a l . 1982), but not demographic consequences. While i n d i c e s o f animal c o n d i t i o n and demographic parameters can r e v e a l the s i g n i f i c a n c e o f both h a b i t a t and human r e l a t e d b e h a v i o r a l d i s t u r b a n c e e f f e c t s , e s t i m a t i n g these can be c o s t l y and time consuming. Twenty-four hour a c t i v i t y budgets are measures of how animals p a r t i t i o n t h e i r time i n t o v a r i o u s b e h a v i o r s (Boy and Duncan 1979). As a component o f b i o e n e r g e t i c s , a c t i v i t y budgets have 3 a p p l i c a t i o n i n p o p u l a t i o n dynamics, h a b i t a t m a n i p u l a t i o n , assessment o f r e s o u r c e development impacts (Hudson and White 1985; Jacobsen and Wiggins 1982) and the development o f t h e o r e t i c a l time-energy budget models (Jacobsen and Wiggins 1982). A c t i v i t y p a t t e r n s denote the temporal d i s t r i b u t i o n o f a c t i v i t y over the 24-hour c y c l e . Q u a n t i f y i n g t h e s e a c t i v i t y parameters o f a s p e c i e s under a v a r i e t y o f environmental c o n d i t i o n s may u l t i m a t e l y p ermit t h e i r use as i n d i c a t o r s of s t r e s s p l a c e d on a g i v e n p o p u l a t i o n by i t s environment (Roth 1983). However, evidence o f a l t e r e d a c t i v i t y budgets o r p a t t e r n s are not i n themselves evidence o f d e t r i m e n t a l e f f e c t s on the p o p u l a t i o n . To be o f g e n e r a l u t i l i t y , a c t i v i t y parameters need t o r e f e r e n c e d a g a i n s t known p o p u l a t i o n s t a t u s . P r e v i o u s r e s e a r c h on g r i z z l y bears i n t h e F l a t h e a d R i v e r drainage has documented short-term, o v e r t b e h a v i o r a l responses t o human d i s t u r b a n c e , s p a t i a l d i s t r i b u t i o n s as i n f l u e n c e d by roads, and p o p u l a t i o n demographics (McLellan 1989a, 1989b, 1989c; M c L e l l a n and S h a c k l e t o n 1989a, 1989b, 1988a, 1988b). The F l a t h e a d study a r e a p r o v i d e s a unique o p p o r t u n i t y t o l i n k a c t i v i t y parameters t o a w e l l documented p o p u l a t i o n . Knowledge o f a c t i v i t y p a t t e r n s f o r g r i z z l i e s may a l s o h e l p reduce the o c c u r r e n c e o f bear-human encounters and improve r e s e a r c h schedules ( H a r t i n g 1987). The main focus o f t h i s r e s e a r c h was t o document the temporal d i s t r i b u t i o n s ( a c t i v i t y p a t t e r n s ) and amount o f a c t i v i t y ( a c t i v i t y budgets) of g r i z z l y bears over the 24- 4 hour c y c l e as f u n c t i o n s o f sex, age c l a s s , season, and the d a i l y s o l a r c y c l e . A d d i t i o n a l hypotheses concerned d u r a t i o n s o f both a c t i v e and i n a c t i v e p e r i o d s . However, i t was not p o s s i b l e t o c o r r e l a t e r e c o r d e d s i g n a l p a t t e r n s from m o t i o n - s e n s i t i v e c o l l a r s w i t h c o n c u r r e n t o b s e r v a t i o n s o f g r i z z l y bears due t o the d i f f i c u l t y o f o b s e r v i n g f r e e - r a n g i n g b e a r s . T h e r e f o r e , i t was necessary t o f i r s t a s s ess procedures employed t o t r a n s l a t e c h a r t r e c o r d i n g s i n t o measures o f bear a c t i v i t y through o t h e r means. S p e c i f i c hypotheses a re d e l i n e a t e d and a p p r a i s e d i n each o f the f o l l o w i n g c h a p t e r s . STUDY AREA The study area was c e n t e r e d a l o n g the North Fork o f the F l a t h e a d R i v e r (114° 85 1 W; 49° 1' N) which d r a i n s the extreme southeast c o r n e r o f B r i t i s h Columbia, Canada, and p a r t s o f northwestern Montana, U. S. A. The g r i z z l y bear p o p u l a t i o n i n t h i s area has been under study s i n c e 1978 by B. N. M c L e l l a n and o t h e r s o f the F l a t h e a d G r i z z l y P r o j e c t ( M c L e l l a n 1989a, 1989b, 1989c; M c L e l l a n and Sh a c k l e t o n 1989a, 1989b, 1988a, 1988b). Boundaries t o the p r o j e c t ' s study a r e a a re determined by the home ranges o f g r i z z l y bears c a p t u r e d and c o l l a r e d i n a 264 km2 c e n t r a l t r a p p i n g a r e a . These home ranges d e f i n e an area o f 2820 km2 (McLellan 1989a) spanning the i n t e r n a t i o n a l boundary w i t h Montana. M o n i t o r i n g o f bears f o r a c t i v i t y d ata was conducted w i t h i n a subset study area of approximately 1000 5 km2. T h i s subset was bounded by the C l a r k Range on the e a s t , the McDonald (Whitefish) Range on the west, w i t h e x t e n s i o n s 30 km n o r t h and 15 km south of the 49th p a r a l l e l . The F l a t h e a d R i v e r flows south through the study area a l o n g a 5 t o 10 km wide v a l l e y c h a r a c t e r i z e d by r i v e r f l a t s , r o l l i n g h i l l s and benches. V a l l e y bottom e l e v a t i o n s range from 1350 m above sea l e v e l i n the n o r t h t o 1100 m above sea l e v e l i n the south. Mountain ranges r i s e up t o e l e v a t i o n s i n excess o f 2800 m above sea l e v e l on e i t h e r s i d e and h a r bor numerous s i d e d r a i n a g e s . Lower e l e v a t i o n s o f the study a r e a l i e w i t h i n the Montane Spruce B i o g e o c l i m a t i c Zone (B.C.M.O.F. 1988) c h a r a c t e r i z e d by c o l d w i n t e r s and moderately s h o r t , warm summers. Higher e l e v a t i o n s f a l l w i t h i n the Engelmann Spruce - Subalpine F i r Zone w i t h l o n g c o l d w i n t e r s and s h o r t c o o l summers. The uppermost e l e v a t i o n s are i n the A l p i n e Tundra Zone which has a h a rsh c l i m a t e . Approximate c l i m a t o l o g i c a l f e a t u r e s o f the area i n c l u d e mean d a i l y temperatures o f -15 °C i n January and < 16 °C i n J u l y , an average f r o s t f r e e p e r i o d < 60 days, and mean annual p r e c i p i t a t i o n of 100 - 150 cm ( F a r l e y 1979). W i l d f i r e s around the t u r n o f t h e c e n t u r y , c o u p l e d w i t h b e e t l e i n f e s t a t i o n s and l o g g i n g i n the mid-1900s and a g a i n i n the 1970s and 1980s (Zager e t a l . 1983) have r e s u l t e d i n s u c c e s s i o n a l l o d g e p o l e p i n e (Pinus c o n t o r t a ) dominating lower e l e v a t i o n s . Englemann spruce ( P i c e a enqelmannii x gXauca), s u b a l p i n e f i r (Abies l a s i o c a r p a ) and white bark p i n e (Pinus a l b i c u a l i s ) are l o c a l l y abundant, becoming 6 common a t h i g h e r e l e v a t i o n s and i n s i d e d r a i n a g e s . L a r c h (Laryx o c c i d e n t a l i s m and a l p i n e l a r c h (Laryx l v a l l i ) a r e s c a t t e r e d throughout the lower and upper e l e v a t i o n s , r e s p e c t i v e l y . Many h i g h e l e v a t i o n s i t e s , p a r t i c u l a r l y those b o r d e r i n g on the F l a t h e a d B a s i n , have sparse t r e e cover and are dominated by h u c k l e b e r r y (Vaccinium g l o b u l a r e ) . Human impacts i n the study area a re s h a r p l y d e l i n e a t e d by 3 p o l i t i c a l boundaries. The Canadian s i d e has undergone e x t e n s i v e c l e a r c u t l o g g i n g and e x p l o r a t i o n f o r o i l and gas but has l i t t l e human se t t l e m e n t . The American s i d e i s d i v i d e d between a r u r a l environment a l o n g the west s i d e o f the F l a t h e a d R i v e r and the r e l a t i v e l y p r i s t i n e w i l d e r n e s s o f G l a c i e r N a t i o n a l Park on the e a s t s i d e o f the r i v e r . With th e e x c e p t i o n o f the park, b i g game h u n t i n g o c c u r s throughout t h e study area and i n c l u d e s h u n t i n g f o r g r i z z l i e s . FIELD PROCEDURES G r i z z l y bears were captured by p e r s o n n e l o f t h e F l a t h e a d G r i z z l y P r o j e c t i n A l d r i c h f o o t snares o r c u l v e r t t r a p s and o u t f i t t e d w i t h e i t h e r 2.5-min o r 5-s r e s e t d e l a y a c t i v i t y c o l l a r s ( T e l o n i c s L t d , A r i z o n a ; 164 - 166 MHz). Both c o l l a r types u t i l i z e d a mercury t i p - s w i t c h t h a t when a c t i v a t e d by movement changed from an i n a c t i v e s i g n a l p u l s e r a t e o f approximately 50 p u l s e s p e r min t o an a c t i v e s i g n a l p u l s e r a t e o f approximately 75 p u l s e s p e r min. While the p u l s e r a t e changed from i n a c t i v e t o a c t i v e mode 7 i n s t a n t a n e o u s l y , the s i g n a l remained i n a c t i v e p u l s e mode f o r the time d e l a y p e r i o d (2.5-min or 5-s) b e f o r e r e t u r n i n g t o i n a c t i v e mode. Subsequent movement by the bear b e f o r e e x p i r y o f the d e l a y p e r i o d caused the c o l l a r s t o r e s e t t o the b e g i n n i n g of the d e l a y p e r i o d without i n t e r r u p t i o n o f the a c t i v e p u l s e mode. S i g n a l p u l s e modes and amplitudes t r a n s m i t t e d from the c o l l a r s o f i n d i v i d u a l bears were reco r d e d u s i n g 2 remote da t a r e c o r d i n g systems ( T e l o n i c s L t d , Arizona) t h a t each c o n s i s t e d o f a TR-2 t e l e m e t r y r e c e i v e r , a TDP-2 d i g i t a l data p r o c e s s o r , and a Rustrack d u a l channel s t r i p c h a r t r e c o r d e r (Gulton Graphic Instruments D i v i s i o n , New Hampshire) a l l housed i n a water r e s i s t a n t , metal case. Twelve v o l t c a r b a t t e r i e s o r CF12V5PP r e c h a r g e a b l e b a t t e r i e s ( E a g l e - P i c h e r I n d u s t r i e s , M i s s o u r i ) were used t o power the r e c o r d i n g systems. The c h a r t r e c o r d e r s were s e t t o run a t a c h a r t speed o f 16 i n (40.6 cm) per h ( a c t u a l speed v a r i e d w i t h l e v e l o f b a t t e r y charge and ambient temperature). A t t h i s speed even i s o l a t e d o ccurrences of i n d i v i d u a l 5 s p e r i o d s of a c t i v e p u l s e mode were r e a d i l y i d e n t i f i a b l e . Data c o l l e c t i o n was conducted from a number o f f a v o r a b l e l o c a t i o n s g e n e r a l l y on h i l l t ops and benches, and when a v a i l a b l e from a h i g h e l e v a t i o n f i r e l o o k o u t (2100 m above sea l e v e l ) o v e r l o o k i n g the study area. Recording s e s s i o n s noted the bear's i d e n t i f i c a t i o n , g e n e r a l weather c o n d i t i o n s , date, s t a r t and stop time o f the r e c o r d i n g , and l o c a t i o n from which the r e c o r d i n g was taken. Whenever 8 p o s s i b l e , the bear was r e l o c a t e d u s i n g t e l e m e t r y . Recorders were checked f r e q u e n t l y t o ensure t h a t the bear was s t i l l i n range, and t o mark time checks on the c h a r t s f o r c a l i b r a t i n g c h a r t speed. Sampling o f i n d i v i d u a l bears was f r e q u e n t l y o p p o r t u n i s t i c and data c o l l e c t i o n on a s u b j e c t was continuous u n t i l the bear went out o f range o r an adequate sample (at l e a s t 24 h) was o b t a i n e d . I n d i v i d u a l r e c o r d i n g s e s s i o n s v a r i e d g r e a t l y i n l e n g t h from < 1 h t o > 48 h. DISTRIBUTION OF DATA A c t i v i t y r e c o r d i n g s on g r i z z l i e s used i n t h i s study were c o l l e c t e d over 5 c o n s e c u t i v e y e a r s from 1984 through t o 1988. A t o t a l o f 4757 h of r e c o r d e d data were c o l l e c t e d w i t h t h e m a j o r i t y o b t a i n e d i n 1987 and 1988 (60.6% and 23.5% o f t o t a l , r e s p e c t i v e l y ) . Data were c o l l e c t e d on 15 i n d i v i d u a l bears, but due t o the l o n g time span over which data were a c q u i r e d , s e v e r a l i n d i v i d u a l s passed from s u b a d u l t s (1 - 4 y o f age) t o a d u l t s (> 5 y old) and (or) changed r e p r o d u c t i v e s t a t u s . For a n a l y t i c a l purposes, bears t h a t o c c u r r e d i n more than 1 sex-age o r r e p r o d u c t i v e c l a s s were t r e a t e d as independent i n d i v i d u a l s w i t h i n each c l a s s . Appendix 1 o u t l i n e s t o t a l time o f rec o r d e d d a t a f o r i n d i v i d u a l s by y e a r and season and i n d i c a t e s sex, age c l a s s , and r e p r o d u c t i v e s t a t u s . Pooled data t o t a l s on i n d i v i d u a l s w i t h i n sex-age c l a s s e s ranged from 41.5 hours t o 641.9 hours. 9 Dates o f data c o l l e c t i o n range from 13 A p r i l t o 27 October, and f o r a d u l t females and su b a d u l t s o f both sexes t h i s approximately covers the p e r i o d from den emergence t o den entrance. A d u l t males g e n e r a l l y emerge from dens e a r l i e r i n the s p r i n g and e n t e r dens l a t e r i n the f a l l ( M c L e l l a n p e r s . comm.). A d d i t i o n a l l y , data on a d u l t males were s p a r s e i n both A p r i l and October (Table 1 ) . Few a d u l t females wearing a c t i v i t y c o l l a r s were w i t h c u b s - o f - t h e - y e a r o r y e a r l i n g s d u r i n g t h e study (Table 1). Based on p h e n o l o g i c a l development o f major g r i z z l y bear forage s p e c i e s and observed h a b i t a t and d i e t a r y change o f the bears (McLellan p e r s . comm.), the p e r i o d from den emergence t o den entrance was p a r t i t i o n e d i n t o f o u r seasons: 1) s p r i n g - den emergence t o the average date o f green-up on May 9; 2) e a r l y summer - May 10 t o the average date o f b e r r y r i p e n i n g on J u l y 24; 3) b e r r y season - J u l y 25 t o the average date o f bears l e a v i n g h i g h e l e v a t i o n b e r r y f i e l d s on September 19; and 4) f a l l - September 20 t o den entrance. Most a n a l y s e s were conducted w i t h i n o r among seasons (Table 2 ) . Table 1. D i s t r i b u t i o n o f recorded data (sum of a c t i v e and i n a c t i v e bout durations) by p o p u l a t i o n component and month f o r 1984 through 1988 combined, i n a decimal hours. Number of bears i n each monthly sample are i n bracke t s . Po p u l a t i o n Component A p r i l Mav June J u l y August Sept Oct A l l A d u l t 157.98 470. 88 175.07 296.15 224.17 253.32 126. 05 Females (3) (4) (3) (4) (4) (4) (4) b w i t h COYS 64.52 166. 57 37.45 — — 21.90 -- (1) (1) (2) (1) with y e a r l i n g s — — — 70.42 65.25 57.95 81.93 52 . 33 (1) (1) (1) (2) (2) alone or with 93.47 304. 32 67.20 230.90 166.22 149.48 73. 72 2-year-olds (2) (4) (3) (3) (3) (2) (2) A d u l t 16.02 149. 88 111.23 163.17 252.08 87.47 51. 82 Males (2) (3) (2) (2) (2) (3) (3) Subadult 38.60 258. 62 159.13 170.50 176.52 231.17 122. 25 Females (2) (3) (4) (2) (4) (4) (3) Subadult 74.68 49. 30 166.48 138.72 168.70 285.98 181. 02 Males (1) (3) (4) (3) (3) (4) (4) T0TAL C 287.28 928. 68 611.91 768.54 821.47 857.94 481. 14 (8) (11) (11) (11) (11) (12) (11) Some bears appear i n more than 1 p o p u l a t i o n component due t o changes i n age c l a s s and r e p r o d u c t i v e s t a t u s over the sample years. b COYS = cubs-of-the-year. c TOTAL = sum of a d u l t females, a d u l t males, subadult females, subadult males. Number of bears r e p r e s e n t s unique i n d i v i d u a l s . T a b l e 2. D i s t r i b u t i o n of recorded data (sum of a c t i v e and i n a c t i v e bout durations) by p o p u l a t i o n component and season f o r 1984 through 1988 combined, i n a decimal hours. Number of bears i n each seasonal sample are i n bracke t s . P o p u l a t i o n E a r l y Berry F a l l Component Spr i n q Summer Season A l l A d u l t 221.18 , 826.47 399.18 256.83 Females (3) (4) (5) (4) w i t h COYS b 66.93 201.62 — 21.90 (1) (2) (1) w i t h y e a r l i n g s — 135.68 93.48 98.77 (1) (1) (2) alone or with 154.25 489.18 305.70 136.17 2-year-olds (2) (4) (4) (2) A d u l t 52.63 316.80 393.43 68.82 Males (2) (3) (2) (3) Subadult 230.48 361.55 313.53 251.27 females (3) (4) (5) (4) Subadult 90.05 291.62 477.33 205.88 Males (2) (5) (4) (4) TOTAL° 594.34 1796.44 1583.47 782.80 (9) (13) (13) (12) Some bears appear i n more than 1 p o p u l a t i o n component due t o changes i n age c l a s s and r e p r o d u c t i v e s t a t u s over the sample y e a r s . b COYS = cubs-of-the-year. c TOTAL = sum of a d u l t females, a d u l t males, subadult females, subadult males, Number of bears r e p r e s e n t s unique i n d i v i d u a l s . 12 LITERATURE CITED A r c h i b a l d , W. R., R. E l l i s , and A. N. Hamilton. 1987. Responses of g r i z z l y bears t o l o g g i n g t r u c k t r a f f i c i n the Kimsquit R i v e r v a l l e y , B r i t i s h Columbia. I n t . Conf. Bear Res. and Manage. 7:251-257. Boy, V., and P. Duncan. 1979. Time-budgets o f Camarque hor s e s . 1. Developmental changes i n the time-budgets of f o a l s . Behaviour 71:187-202. B r i t i s h Columbia M i n i s t r y o f F o r e s t s , 1988. B i o g e o c l i m a t i c zones of B r i t i s h Columbia 1988. B r i t i s h Columbia M i n i s t r y o f F o r e s t s , V i c t o r i a , B r i t i s h Columbia. 1:2,000,000 c o l o r e d map. B u n n e l l , F. L., and D. E. N. T a i t . 1981. P o p u l a t i o n dynamics o f bears - i m p l i c a t i o n s . In Dynamics of l a r g e mammal p o p u l a t i o n s . E d i t e d by. C. W. Fowler and T. D. Smith. John Wiley & Sons Inc., New York, New York. pp. 75-98. C h u r c h i l l , B. P. 1982. Winter h a b i t a t s e l e c t i o n and use of c l e a r c u t s by e l k i n the White R i v e r d r a inage o f so u t h e a s t e r n B r i t i s h Columbia. M.Sc. T h e s i s , Univ. o f B r i t i s h Columbia, Vancouver, B r i t i s h Columbia. 95 pp. F a r l e y , A. L. 1979. A t l a s o f B r i t i s h Columbia: people, environment and r e s o u r c e use. UBC Press, Vancouver, B r i t i s h Columbia. 136 pp. H a r t i n g , A. L. 1987. A c t i v i t y p a t t e r n s . In G r i z z l y bear compendium. E d i t e d by M. N. LeFranc, M. B. Moss, K. A. Patnode, and W. C. Sugg. U.S. N a t i o n a l W i l d l i f e F e d e r a t i o n , Washington, D.C. pp. 33-35. Herrer o , S. 1972. I n t r o d u c t i o n t o the b i o l o g y and management of b e a r s . I n t . Conf. Bear Res. and Manage. 2:11-18. Herrer o , S. 1976. C o n f l i c t s between man and g r i z z l y bears i n the n a t i o n a l parks of North America. I n t . Conf. Bear Res. and Manage. 3:121-145. 13 Hudson, R. J . , and R. G. White. 1985. P r e f a c e . In B i o e n e r g e t i c s o f w i l d h e r b i v o r e s . E d i t e d by. R. J . Hudson and R. G. White. CRC Pr e s s , Boca Raton, F l o r i d a . 314 pp. Jacobsen, N. K,. and A. D. Wiggins. 1982. Temporal and p r o c e d u r a l i n f l u e n c e s on a c t i v i t y e s t i m a t e d by time- sampling. J . W i l d l . Manage. 46:313-324. Knight, R. R. 1980. B i o l o g i c a l c o n s i d e r a t i o n s i n t h e d e l i n e a t i o n o f c r i t i c a l h a b i t a t . I n t . Conf. Bear Res. and Manage. 4:1-3. MacArthur, R. A., V. G e i s t , and R. H. Johnston. 1982. C a r d i a c and b e h a v i o r a l responses o f mountain sheep t o human d i s t u r b a n c e . J . W i l d l . Manage. 46:351-358. M c L e l l a n , B. N. 1989a. Dynamics of a g r i z z l y bear p o p u l a t i o n d u r i n g a p e r i o d of i n d u s t r i a l r e s o u r c e e x t r a c t i o n . I . D e n s i t y and age-sex composition. Can. J . Z o o l . 67:1856- 1860. M c L e l l a n , B. N. 1989b. Dynamics of a g r i z z l y bear p o p u l a t i o n d u r i n g a p e r i o d o f i n d u s t r i a l r e s o u r c e e x t r a c t i o n . I I . M o r t a l i t y r a t e s and causes o f death. Can. J . Z o o l . 67:1861-1864. M c L e l l a n , B. N. 1989c. Dynamics o f a g r i z z l y bear p o p u l a t i o n d u r i n g a p e r i o d o f i n d u s t r i a l r e s o u r c e e x t r a c t i o n . I I I . N a t a l i t y and r a t e o f i n c r e a s e . Can. J . Z o o l . 67:1865- 1868. M c L e l l a n , B. N., and D. M. Shackleton. 1988a. G r i z z l y bears and r e s o u r c e - e x t r a c t i o n i n d u s t r i e s : e f f e c t s o f roads on behaviour, h a b i t a t use and demography. J . A p p l . E c o l . 25:451-460. M c L e l l a n , B. N., and D. M. Shackleton. 1988b. A comparison o f g r i z z l y bear h a r v e s t data from Montana and s o u t h e a s t e r n B r i t i s h Columbia. W i l d l . Soc. B u l l . 16:371-375. 14 M c L e l l a n , B. N., and D. M. Shackleton. 1989a. G r i z z l y bears and r e s o u r c e - e x t r a c t i o n i n d u s t r i e s : h a b i t a t displacement i n response t o s e i s m i c e x p l o r a t i o n , timber h a r v e s t i n g and road maintenance. J . A p p l . E c o l . 26:371- 380. M c L e l l a n , B. N., and D. M. Shackleton. 1989b. Immediate r e a c t i o n s o f g r i z z l y bears t o human a c t i v i t i e s . W i l d l . Soc. B u l l . 17:269-274. Roth, H. U. 1983. D i e l a c t i v i t y o f a remnant p o p u l a t i o n o f European brown bears. I n t . Conf. Bear Res. and Manage. 5:223-229. Shank, C. C. 1979. Human-related b e h a v i o r a l d i s t u r b a n c e t o n o r t h e r n l a r g e mammals: a b i b l i o g r a p h y and review. F o o t h i l l s P i p e l i n e s (South Yukon) L t d . , C a l g a r y , A l b e r t a . 253 pp. Zager, P. E., C. J o n k e l , and J . Habeck. 1983. Logging and w i l d f i r e i n f l u e n c e on g r i z z l y bear h a b i t a t i n northwestern Montana. I n t . Conf. Bear Res. and Manage. 5:124-132. 15 CHAPTER 2: ASSESSING ACTIVITY FROM CHART RECORDINGS INTRODUCTION The use o f b i o t e l e m e t r y t o study a c t i v i t y budgets and p a t t e r n s o f f r e e - r a n g i n g animals has been e x t e n s i v e w i t h r e s p e c t t o the number o f s t u d i e s and the number o f s p e c i e s . Obvious advantages t o remote s e n s i n g i n c l u d e 1) r e d u c t i o n or e l i m i n a t i o n o f observer e f f e c t s on the s u b j e c t ' s b e h a v i o r , 2) freedom from the need f o r d i r e c t o b s e r v a t i o n of the s u b j e c t which can be compromised due t o darkness, dense cover o r m o b i l i t y on the p a r t of the s u b j e c t , and 3) i n c r e a s e d o b s e r v e r s a f e t y i n the case o f p o t e n t i a l l y dangerous animals. Disadvantages stem from r e l a t i n g the monitored analog t o the b e h a v i o r a l s t a t e of t h e animal. Instantaneous changes i n the v a r i a b l e monitored (e.g., s i g n a l i n t e g r i t y , s i g n a l p u l s e r a t e ) i n t r o d u c e u n c e r t a i n t y (and hence i n a c c u r a c i e s ) , w h i l e p r o c e d u r a l b i a s e s may favour p a r t i c u l a r b e h a v i o r a l s t a t e s (Jacobsen and Wiggins 1982). Such b i a s e s may e v o l v e from r u l e s employed t o c a t e g o r i z e the analog t o a b e h a v i o r a l s t a t e (Smith 1986; L i n d z e y and Meslow 1977), from sampling techniques, o r from temporal changes i n the s u b j e c t s ' b e h a v i o r (Jacobsen and Wiggens 1982). Coupled w i t h t h i s are p o t e n t i a l d i f f e r e n c e s i n the s e n s i t i v i t y o f i n d i v i d u a l c o l l a r s and the i n a b i l i t y o f most t i p - s w i t c h c o l l a r s t o d e t e c t movement on more than one p l a n e . P r e v i o u s work on b i o t e l e m e t r i c m o n i t o r i n g o f g r i z z l y and b l a c k bear (Ursus americanus) a c t i v i t y e i t h e r used the 16 s i g n a l i n t e g r i t y of f i x e d p u l s e r a t e c o l l a r s as an i n d i c a t o r of a c t i v i t y (e.g., B j a r v a l l and Sandegren 1987; Roth and Huber 1986; H a r t i n g 1985; Roth 1983; L i n d z e y and Meslow 1977; Amstrup and Beecham 1976), employed t i p - s w i t c h c o l l a r s t h a t a l t e r n a t e between 2 p u l s e modes (slow and f a s t ) depending on c o l l a r o r i e n t a t i o n (e.g., H a r t i n g 1985; S c h l e y e r 1983; G a r s h e l i s e t a l . 1982; G a r s h e l i s and P e l t o n 1980), o r used t i p - s w i t c h c o l l a r s w i t h v a r i o u s r e s e t d e l a y p e r i o d s r a n g i n g from 1 t o 5 min (Clevenger e t a l . 1990; Ayres e t a l . 1986; Smith 1986; G a r s h e l i s e t a l . 1982). In the p r e v i o u s s t u d i e s , c o l l e c t i o n of data i n v o l v e d p e r i o d i c a l l y sampling the c o l l a r s ' s i g n a l p u l s e p a t t e r n s (time-sampling) and employing v a r i o u s r u l e s t o determine i f the bear s h o u l d be c l a s s i f i e d as a c t i v e or i n a c t i v e . Both sampling p e r i o d and i n t e r v a l s between samples v a r i e d g r e a t l y between s t u d i e s . Only Smith (1986) c o l l e c t e d d a t a v i a continuous m o n i t o r i n g o f r a d i o c o l l a r s i g n a l s (as used here continuous m o n i t o r i n g r e f e r s t o the r e c o r d i n g o f a l l - o c c u r r e n c e s o f the b e h a v i o r s of i n t e r e s t ) , however, i t was done manually and was not e x t e n s i v e . In a l l the above s t u d i e s , r e s o l u t i o n o f b e h a v i o r was c o a r s e - g r a i n e d and i n v o l v e d o n l y c l a s s i f y i n g b e h a v i o r as e i t h e r a c t i v e or i n a c t i v e . S t u d i e s u t i l i z i n g s i g n a l i n t e g r i t y g e n e r a l l y used q u a l i t a t i v e r u l e s t o a s s i g n a c t i v i t y s t a t e . Rules used t o determine the s t a t e o f the bear f o r t i p - s w i t c h c o l l a r s , g e n e r a l l y r e l i e d on c o u n t i n g t h e number o f p u l s e mode changes per u n i t time and 17 c l a s s i f y i n g as i n a c t i v e those samples c o n t a i n i n g l e s s than some minimum number of changes. Assignment o f a sample as a c t i v e o r i n a c t i v e was independent o f the p r e v i o u s o r f o l l o w i n g samples' assignment. Jacobsen and Wiggins (1982) have termed t h i s "instantaneous time-sampling" and have demonstrated f o r w h i t e - t a i l e d deer (Odocoileus v i r q i n i a n u s ) t h a t i t i s unbiased i n e s t i m a t i n g time i n a c t i v i t y , but i s i n c r e a s i n g l y i n a c c u r a t e as i n t e r v a l s between samples are i n c r e a s e d , o r the sample d u r a t i o n i s decreased. With the e x c e p t i o n o f Clevenger e t a l . (1990), s t u d i e s u s i n g time d e l a y r e s e t c o l l a r s d i d not a s s i g n a c t i v i t y s t a t e t o a l l samples i n s t a n t a n e o u s l y . For some samples, depending on t h e s i g n a l p u l s e mode monitored, assignment o f a c t i v i t y s t a t e depended on a f u t u r e sample meeting some c r i t e r i a . T h i s p r o t o c o l was designed t o d i f f e r e n t i a t e between a c o l l a r s e t i n a c t i v e mode by b r i e f movement o f an i n a c t i v e bear as opposed t o a c o l l a r s e t i n a c t i v e mode by an a c t i v e bear. Smith (1986) and G a r s h e l i s e t a l . (1982), when unable t o i n s t a n t a n e o u s l y a s s i g n a c t i v i t y s t a t e t o a sample, resampled t h e s i g n a l p u l s e mode a f t e r a time i n t e r v a l equal t o o r s l i g h t l y l o n g e r than the c o l l a r ' s time d e l a y r e s e t p e r i o d . Hence, the f u t u r e sample r e q u i r e d f o r d e c i s i o n making was not p a r t o f t h e s y s t e m a t i c sampling scheme. In c o n t r a s t , Ayres e t a l . (1986) sampled o n l y s y s t e m a t i c a l l y , and i f one a c t i v e sample o c c u r r e d between two i n a c t i v e samples, they c l a s s i f i e d t he a c t i v e sample as i n a c t i v e on the assumption t h a t i t was o n l y a b r i e f comfort movement by the bear. When 18 f u t u r e samples must be examined p r i o r t o assignment of b e h a v i o r a l s t a t e i t i s termed " c o n d i t i o n a l time-sampling" (Jacobsen and Wiggins 1982). S t u d i e s on the e f f e c t s o f c o n d i t i o n a l time-sampling by Jacobsen and Wiggins (1982) may not be d i r e c t l y a p p l i c a b l e t o s t u d i e s u t i l i z i n g r e s e t d e l a y c o l l a r s and d i f f e r e n t c o n d i t i o n a l time-sampling r u l e s . However, c a u t i o n i s warranted as a s t r o n g tendency f o r c o n d i t i o n a l time-sampling t o underestimate time i n a c t i v i t y has been demonstrated (Jacobsen and Wiggins 1982). Continuous m o n i t o r i n g o f a c t i v i t y o f f e r s a more a c c u r a t e account of time e x p e n d i t u r e s and sequencing among a c t i v i t i e s than does sampling a t i n t e r v a l s (Jacobsen and Wiggins 1982). F o l l o w i n g Altmann (1974), continuous m o n i t o r i n g r e s u l t s from the c o l l e c t i o n o f f o c a l animal samples and i n v o l v e s r e c o r d i n g a l l - o c c u r r e n c e s o f the b e h a v i o r s o f i n t e r e s t performed by s p e c i f i c ( f o c a l ) i n d i v i d u a l s over a sample p e r i o d o f known l e n g t h . Such data a r e s u i t e d t o s t u d i e s o f b e h a v i o r a l sequences, amount and p e r c e n t o f time spent i n v a r i o u s b e h a v i o r s , and d u r a t i o n s of b e h a v i o r a l bouts (Altmann 1974). However, the c o l l e c t i o n of continuous data tends t o be l i m i t e d by the e f f o r t r e q u i r e d t o c o l l e c t the data (Jacobsen and Wiggins 1982). In c o a r s e - g r a i n e d s t u d i e s o f a c t i v i t y ( a c t i v e vs i n a c t i v e ) , d i v e r s e b e h a v i o r s w i t h d i v e r s e e n e r g e t i c c o s t s are p o o l e d i n t o the a c t i v e s t a t e (much l e s s v a r i a t i o n i s expected among those b e h a v i o r s p o o l e d i n t o i n a c t i v i t y ) . A s i d e from compromising time-energy budgets, a problem 19 a r i s e s when working w i t h continuous data i n terms o f minimum bout l e n g t h s t h a t can be r e c o g n i z e d . For i n s t a n c e , e n e r g e t i c a l l y expensive a c t i v i t y o f s h o r t d u r a t i o n should warrant s p e c i a l r e c o g n i t i o n as should s h o r t bouts o f r e s t i n t e r s p e r s e d w i t h i n v i g o r o u s a c t i v i t y . However, few a c t i v i t y s t u d i e s on any s p e c i e s have employed continuous m o n i t o r i n g . S o r o k i n and Berger (1939), s t u d y i n g time- budgets o f humans reco r d e d every a c t i v i t y t h a t l a s t e d > 5 min. Cederlund (1981) i n work w i t h roe deer (Capreolus c a p r e o l u s ) a l s o d i d not r e c o g n i z e bouts < 5 min but r a t h e r i n c l u d e d such s h o r t bouts w i t h a d j a c e n t a c t i v i t y c a t e g o r i e s . Cederlund and Lemnell (1980) pr e s e n t e d r e s u l t s o f continuous a c t i v i t y m o n i t o r i n g on roe deer and mountain hares (Lepus t i m i d u s ) . w i t h a c t i v i t y bouts > 2 min r e c o g n i z e d as d i s t i n c t u n i t s . These l a t t e r 2 s t u d i e s a l s o d i s t i n g u i s h e d 3 d i f f e r e n t types o f a c t i v e b e h a v i o r . Smith (1986) s t u d i e d h i b e r n a t i n g b l a c k bears and r e c o g n i z e d a l l - o c c u r r e n c e s o f a c t i v e b e h a v i o r , w i t h b r i e f o c c u r r e n c e s o f < 1 min d u r a t i o n r e c o r d e d as 1 min bouts. Because u n c e r t a i n t y e x i s t s i n i n t e r p r e t i n g t h e monitored analog, as s h o r t e r and s h o r t e r a c t i v i t y bouts are r e c o g n i z e d i t i s expected t h a t the e r r o r r a t e i n a c t i v i t y c l a s s i f i c a t i o n w i l l i n c r e a s e . But, e r r o r s i n c l a s s i f i c a t i o n must be random i f the mean es t i m a t e s o f a c t i v i t y are t o be unbiased. A l t e r n a t i v e l y , s y s t e m a t i c e r r o r s i n c l a s s i f i c a t i o n w i l l b i a s the means but w i l l not a f f e c t the 20 r e s u l t s o f s i g n i f i c a n c e t e s t i n g , p r o v i d e d t h a t the magnitude and d i r e c t i o n o f e r r o r s are comparable a c r o s s samples. S p e c i f i c o b j e c t i v e s o f t h i s c h apter were t o : 1) assess the s t a b i l i t y o f c h a r t i n t e r p r e t a t i o n s w i t h v a r y i n g d e f i n i t i o n s o f minimum bout d u r a t i o n ; 2) d e s c r i b e g e n e r a l t r e n d s i n a c t i v i t y budgets and p a t t e r n s ; and 3) ass e s s the v a l i d i t y o f procedures used t o i n t e r p r e t continuous c h a r t r e c o r d e d samples o f bear a c t i v i t y , through q u a l i t a t i v e comparisons w i t h p r e v i o u s r e s e a r c h on a c t i v i t y o f bear s . METHODS Chart I n t e r p r e t a t i o n F i e l d procedures were as d e s c r i b e d i n Chapter 1. A c t i v i t y c o l l a r s used i n t h i s study were e i t h e r o f 5-s or 2.5-min r e s e t d e l a y types (82% and 18% o f re c o r d e d data, r e s p e c t i v e l y ) . I n t e r p r e t a t i o n o f c h a r t r e c o r d i n g s had t o be c o n s i s t e n t between the 2 c o l l a r types i f data were t o be pooled. For the 2.5-min r e s e t d e l a y c o l l a r s , t he minimum d e t e c t a b l e i n a c t i v e d u r a t i o n had a lower bound o f 2.5 min w h i l e a c t i v e p e r i o d s meant t h a t the bear was t r i g g e r i n g the t i p - s w i t c h a t l e a s t once every 2.5 min. Data from t h e 5-s r e s e t d e l a y c o l l a r s were i n t e r p r e t e d i n a manner c o n s i s t e n t w i t h t h e s e r e s t r i c t i o n s . There was l i t t l e o p p o r t u n i t y t o d i r e c t l y observe c o l l a r e d bears (bears wearing 2.5-min r e s e t d e l a y c o l l a r s were never observed). When c o l l a r e d bears c o u l d be observed and s i m u l t a n e o u s l y r e c o r d e d o r l i s t e n e d t o w i t h a r e c e i v e r , 21 i t was apparent t h a t bears wearing 5-s r e s e t d e l a y c o l l a r s c o u l d be a c t i v e f o r almost 1 min without t r i p p i n g the t i p - s w i t c h from i n a c t i v e mode. T h e r e f o r e , s i g n a l p u l s e p a t t e r n s had d i f f e r e n t i a l r e l i a b i l i t y o f the i n f o r m a t i o n t h a t they c o n t a i n e d - a c t i v e p u l s e modes i n d i c a t e d movement but s h o r t d u r a t i o n s o f i n a c t i v e p u l s e modes d i d not p r e c l u d e movement by the bear. Based on the l i m i t a t i o n s o f the 2.5-min r e s e t d e l a y c o l l a r s and the o b s e r v a t i o n s o f bears wearing 5-s r e s e t d e l a y c o l l a r s , minimum d u r a t i o n s f o r r e c o g n i t i o n o f a c t i v e and i n a c t i v e bouts were chosen t o be 1 min and 2.5 min, r e s p e c t i v e l y . A c t i v e bouts were measured t o a s h o r t e r d u r a t i o n t o account f o r the d i f f e r e n t i a l i n i n f o r m a t i o n r e l i a b i l i t y . I n t e r p r e t a t i o n o f c h a r t s c o n s i s t e d o f 2 s t e p s . P u l s e mode p a t t e r n s were f i r s t c a t e g o r i z e d i n t o those c o n s i s t e n t w i t h a c t i v e and i n a c t i v e s t a t e s based on mut u a l l y e x c l u s i v e , q u a n t i t a t i v e r u l e s . C a t e g o r i z e d p a t t e r n s were then a s s i g n e d as a c t i v e o r i n a c t i v e bouts i f the p a t t e r n p e r s i s t e d f o r a t l e a s t the r e s p e c t i v e minimum d u r a t i o n (1 or 2.5 min) r e q u i r e d f o r r e c o g n i t i o n . C a t e g o r i z e d p u l s e mode p a t t e r n s too s h o r t t o be r e c o g n i z e d as bouts were combined w i t h a d j a c e n t r e c o g n i z a b l e bouts. D u r a t i o n s > 5 min, where the bears* s t a t e c o u l d not be determined, were r e c o r d e d as unknown bouts, s h o r t e r d u r a t i o n s were i n t e r p o l a t e d a c r o s s i f they o c c u r r e d between l i k e bouts, o r s p l i t e v e n l y i f they o c c u r r e d between u n l i k e bouts. 22 Because t h e r e was v a r i a t i o n i n the c h a r t speeds, due t o the l e v e l o f b a t t e r y charge and (or) ambient temperature, t h e c h a r t d i s t a n c e t h a t r e p r e s e n t e d a g i v e n d u r a t i o n v a r i e d w i t h i n and between c h a r t s . Average c h a r t speed was c a l c u l a t e d between time checks on the c h a r t s and c a l i p e r s were s e t t o t h e d i s t a n c e s t h a t r e p r e s e n t e d the d u r a t i o n s used t o d i f f e r e n t i a t e p u l s e mode p a t t e r n s and bouts. P u l s e mode p a t t e r n s d i f f e r e d g r e a t l y between the 2 c o l l a r t y p e s and n e c e s s i t a t e d d i f f e r e n t r u l e s f o r c a t e g o r i z i n g p a t t e r n s i n t o t he 2 s t a t e s . S p e c i f i c r u l e s f o r each c o l l a r type were as f o l l o w s : a) 2.5-min Reset Delay C o l l a r s The 2.5-min d e l a y p e r i o d g r e a t l y c o n s t r a i n e d the frequency w i t h which the p u l s e modes c o u l d a l t e r n a t e . Movement which t r i p p e d the t i p - s w i t c h r e s u l t e d i n a minimum a c t i v e mode o f 2.5 min. However, the d e l a y p e r i o d d i d not apply t o i n a c t i v e p u l s e modes and the c o l l a r c o u l d r e t u r n t o i n a c t i v e mode f o r v e r y b r i e f p e r i o d s b e f o r e been t r i p p e d by movement a g a i n ( F i g . 1 ) . Because o f the r e s e t d e l a y p e r i o d , p o i n t s o f change i n p u l s e mode from a c t i v e t o i n a c t i v e were b i a s e d i n d i c a t o r s o f when the bear ceased movement. T h e r e f o r e , a c o r r e c t i o n o f 2.5 min was added t o the b e g i n n i n g o f any i n a c t i v e p u l s e mode and s u b t r a c t e d from the end o f the p r e c e d i n g p u l s e mode ( F i g . 2 ) . Because o f the r e q u i r e d 2.5 min c o r r e c t i o n , any occurrence o f i n a c t i v e p u l s e mode was r e c o g n i z e d as an i n a c t i v e bout. A c t i v e p u l s e F i g u r e 1. T y p i c a l p u l s e mode pa t t e r n s obtained from bears wearing 2.5-min r e s e t delay c o l l a r s , a) A c t i v e p u l s e modes i n t e r s p e r s e d w i t h b r i e f i n a c t i v e p u l s e modes (marked by arrows), and b) i n a c t i v e p u l s e modes i n t e r s p e r s e d w i t h a c t i v e p u l s e modes of approximately the 2.5-min r e s e t d e l a y p e r i o d . One i n c h of c h a r t t r a c e represents about 4 min. I F i g u r e 2. Examples of assignment of a c t i v i t y bouts (upper continuous l i n e ) t o p u l s e mode p a t t e r n s (lower broken s e r i e s ) obtained from bears wearing 2.5-min r e s e t delay c o l l a r s . Read from l e f t t o r i g h t : U = unknown bout; A = a c t i v e bout (as measured when f o l l o w i n g bout i s unknown); I = i n a c t i v e bout (note a d d i t i o n of 2.5 min c o r r e c t i o n ) ; A = a c t i v e bout (note s u b t r a c t i o n o f 2.5 min when f o l l o w i n g bout i s i n a c t i v e ) ; I = i n a c t i v e bout; A = a c t i v e bout. One inch of c h a r t t r a c e represents about 4 min. 25 modes t h a t preceded i n a c t i v e bouts were r e c o g n i z e d as an a c t i v e bout when the d u r a t i o n between the f i r s t a c t i v e p u l s e mode and the r e s e t d e l a y c o r r e c t i o n was > 1 min ( F i g . 2 ) . When a c t i v e p u l s e modes preceded a bout c l a s s i f i e d as unknown, the l a s t movement by the bear t o t r i g g e r the t i p - s w i t c h was assumed t o be a t the l a s t a c t i v e p u l s e mode. An a c t i v e bout was r e c o g n i z e d i f the a c t i v e p u l s e mode d u r a t i o n was > 3.5 min thus e n s u r i n g t h a t the s u b j e c t m i n i m a l l y was a c t i v e f o r > 1 min ( F i g . 2 ) . I f the p u l s e mode d u r a t i o n was < 3.5 min, the a c t i v e p u l s e modes were pool e d w i t h the unknown bout. b) 5-s Reset Delay C o l l a r s P u l s e mode p a t t e r n s were much more v a r i a b l e f o r 5-s r e s e t d e l a y c o l l a r s and a c t i v e bears g e n e r a l l y had a p a t t e r n c h a r a c t e r i z e d by fre q u e n t s w i t c h i n g back and f o r t h between a c t i v e and i n a c t i v e p u l s e s ( F i g . 3 ) . I n some i n s t a n c e s , a c t i v e bears d i d demonstrate a steady a c t i v e p u l s e . P u l s e p a t t e r n s c o n s i s t e n t w i t h the a c t i v e s t a t e were where a c t i v e p u l s e modes o c c u r r e d w i t h i n 2.5 min o f each o t h e r . An a c t i v e bout was r e c o g n i z e d i f a p u l s e p a t t e r n c o n s i s t e n t w i t h the a c t i v e s t a t e had a d u r a t i o n > 1 min, as measured from the f i r s t a c t i v e p u l s e t o the l a s t a c t i v e p u l s e ( F i g . 4 ) . D u r a t i o n s o f i n a c t i v e p u l s e modes > 2.5 min, as measured from t h e f i r s t t o the l a s t i n a c t i v e p u l s e , were r e c o g n i z e d as i n a c t i v e bouts ( F i g 4 ) . ~~r~ —1 F i g u r e 3. T y p i c a l pulse mode p a t t e r n s obtained from bears wearing 5-s r e s e t d e l a y c o l l a r s , a) A c t i v e p u l s e mode p a t t e r n showing frequent s w i t c h i n g between a c t i v e and i n a c t i v e p u l s e s , and b) a l t e r n a t i n g a c t i v e and i n a c t i v e ( s o l i d lower trace) p u l s e mode p a t t e r n s . One i n c h of c h a r t t r a c e r e p r e s e n t s about 4 min. F i g u r e 4. Examples of assignment of a c t i v i t y bouts (upper continuous l i n e ) t o p u l s e mode p a t t e r n s (lower broken s e r i e s ) obtained from bears wearing 5-s r e s e t d e l a y c o l l a r s . Read from l e f t t o r i g h t : I = i n a c t i v e bout; U = unknown bout (note the i n c l u s i o n of p u l s e mode p a t t e r n s too s h o r t t o c l a s s i f y a t e i t h e r end of the unknown bout); A = a c t i v e bout (note i n a c t i v e p u l s e mode p a t t e r n s w i t h d u r a t i o n s <2.5 min); I = i n a c t i v e bout (note d u r a t i o n <1 min of a c t i v e p u l s e mode p a t t e r n s w i t h i n i n a c t i v e b o ut); A = a c t i v e bout. One i n c h of c h a r t t r a c e represents about 4 min. 28 F o r each r e c o r d e d sample on a bear, the l e n g t h on the c h a r t o f each bout ( i n c l u d i n g unknown bouts) was measured t o the n e a r e s t 1.0 mm and e n t e r e d s e q u e n t i a l l y i n t o a computer f i l e a l o n g w i t h the c h a r t speed and bout category. Data f i l e s were subsequently c o l l a t e d w i t h i n f o r m a t i o n on sex, age, r e p r o d u c t i v e s t a t u s , c o l l a r type, and date. S t a r t i n g times o f r e c o r d i n g s and the s t a r t i n g and s t o p p i n g times of each bout were c a l c u l a t e d t o the n e a r e s t 1.0 min. Time of day was i n Mountain D a y l i g h t Time. T o t a l d u r a t i o n s spent i n a c t i v e and i n a c t i v e bouts were determined by m u l t i p l y i n g each bout's measured l e n g t h by the c h a r t speed t o determine d u r a t i o n o f time, and summing by bout category. Percent o f time a c t i v e (%TA) was determined as t o t a l time i n t h e a c t i v e bout c a t e g o r y d i v i d e d by the sum o f t o t a l time i n both a c t i v e and i n a c t i v e c a t e g o r i e s . A l l continuous 24-hour samples o f bear a c t i v i t y t h a t were 98% complete ( i . e . , < 2% o f sample coded as unknown bouts) were i d e n t i f i e d . S t a b i l i t y o f A c t i v i t y E s t i m a t e s Chart i n t e r p r e t a t i o n r u l e s were designed p r i m a r i l y t o permit a d e t a i l e d and r e p e a t a b l e c h a r a c t e r i z a t i o n o f the c h a r t p u l s e p a t t e r n s . Short a c t i v e and i n a c t i v e bouts may not r e p r e s e n t t r u e a c t i v i t y s t a t e s on the p a r t o f the animal. Short a c t i v e bouts o c c u r r i n g w i t h i n l o n g i n a c t i v e bouts may o n l y r e f l e c t b r i e f head movements o r comfort movements o f a r e s t i n g bear. Short i n a c t i v e bouts i n t e r s p e r s e d between l o n g a c t i v e bouts may be due t o c o l l a r 29 i n s e n s i t i v i t y t o movement i n c e r t a i n p l a n e s o r t o the animal b e i n g i n a v i g i l a n t s t a t e . To assess the impact o f p o t e n t i a l e r r o r s i n a c t i v i t y c l a s s i f i c a t i o n on r e s u l t a n t e s t i m a t e s o f %TA, I wrote a computer program t h a t p e r m i t t e d me t o i n c r e a s e the minimum d u r a t i o n s r e q u i r e d f o r r e c o g n i t i o n o f bouts. The d u r a t i o n s o f a l l 3 bout types ( a c t i v e , i n a c t i v e , unknown) c o u l d be v a r i e d . Lower bounds t o d u r a t i o n s were determined by those used t o i n t e r p r e t the c h a r t s . D e c i s i o n r u l e s were a p p l i e d by the program's a l g o r i t h m t o t he da t a i n h i e r a r c h i c a l f a s h i o n i n s u c c e s s i v e passes through the da t a . In the f i r s t pass, the d u r a t i o n o f each bout was checked a g a i n s t the new r e s p e c t i v e minimum d u r a t i o n and coded as a success i f i t met the minimum d u r a t i o n . Bouts f a i l i n g t o meet the new minimum d u r a t i o n were coded as a f a i l u r e and c o u l d occur e i t h e r s i n g l y o r i n groups between suc c e s s e s . In the second pass, s i n g l e f a i l u r e s were pool e d w i t h o r s p l i t between ad j a c e n t s u c c e s s f u l bouts. The t h i r d pass a n a l y z e d t h e groups of f a i l u r e s as t o t h e type o f a c t i v i t y they b e s t r e p r e s e n t e d i n r e l a t i o n t o bounding s u c c e s s f u l bouts, and pooled, s p l i t o r a s s i g n e d an a c t i v i t y c l a s s i f i c a t i o n as r e q u i r e d . A l l 5-s r e s e t d e l a y c o l l a r data were a n a l y z e d under 5 d i f f e r e n t s e l e c t e d s e t s o f d e f i n i t i o n s w i t h r e s p e c t t o minimum bout d u r a t i o n s r e q u i r e d f o r r e c o g n i t i o n : s e t #1 - a c t i v e bouts = 1 min, i n a c t i v e bouts = 2.5 min, m i s s i n g bouts = 5 min ( t h i s s e t was i d e n t i c a l t o the c h a r t 30 i n t e r p r e t a t i o n r u l e s ) ; s e t #2 - a c t i v e bouts = 2.5 min, i n a c t i v e bouts = 2.5 min, m i s s i n g bouts = 5.0 min; s e t #3 - a c t i v e bouts, i n a c t i v e bouts, and m i s s i n g bouts, a l l = 5.0 min; s e t #4 - a c t i v e bouts, i n a c t i v e bouts, and m i s s i n g bouts, a l l = 7.5 min; s e t #5 - a c t i v e bouts, i n a c t i v e bouts, and m i s s i n g bouts, a l l = 10.0 min. Sets o f d e f i n i t i o n s were s e l e c t e d a r b i t r a r i l y but were designed t o encompass a range of bout d e f i n i t i o n s t o permit e x p l o r a t i o n o f the impact of v a r y i n g d e f i n i t i o n s on %TA. S t a t i s t i c a l A nalyses The e f f e c t o f the d i f f e r e n t s e t s o f bout d e f i n i t i o n r u l e s on %TA was i n v e s t i g a t e d w i t h i n each season u s i n g f i x e d model re p e a t e d measures a n a l y s e s o f v a r i a n c e (Hicks 1982, p. 239), where p o o l e d data f o r each sex-age c l a s s were the s u b j e c t s on which repeated measures (the 5 s e t s o f r u l e s ) were taken. Complete 24-hour r e c o r d i n g s were used t o t e s t d i f f e r e n c e s i n %TA between sex, age and i n d i v i d u a l s i n a mixed model n e s t e d - f a c t o r i a l a n a l y s i s of v a r i a n c e (Hicks 1982, p. 233), and d i f f e r e n c e s between months and i n d i v i d u a l s i n a mixed model repeated measures a n a l y s i s o f v a r i a n c e . A n a l y s e s based on complete 24-hour r e c o r d i n g s were unbalanced w i t h m i s s i n g c e l l s . Data were a r c s i n e square r o o t transformed (Sokal and R o h l f 1981, p. 427) p r i o r t o a n a l y s e s . A n a l y s e s were performed on UBC GENLIN ( G r i e g and B j e r r i n g 1978). D i f f e r e n c e s between means were 31 i n v e s t i g a t e d w i t h Newman-Keuls range t e s t s (Hicks 1982, p. 51). The a l p h a l e v e l f o r a l l t e s t s was 0.05. RESULTS AND DISCUSSION From a p r a c t i c a l p e r s p e c t i v e , %TA tended t o be r e s i s t a n t t o t h e d i f f e r e n t s e t s o f d e f i n i t i o n s t e s t e d . Subadult males i n the s p r i n g demonstrated the l a r g e s t range i n %TA (54.3% - 62.3%) between d e f i n i t i o n s e t s #2 and #5, r e s p e c t i v e l y . A d u l t males i n the f a l l (34.5% - 37.2%) and s p r i n g (30.8% - 33.2%) showed the next l a r g e s t ranges between s e t s #5 and #1, r e s p e c t i v e l y . A l l 3 o f the s e " s u b j e c t s " were c h a r a c t e r i z e d by s m a l l amounts o f d a t a . A n a l y s e s o f v a r i a n c e showed s i g n i f i c a n t d i f f e r e n c e s i n %TA among the s e t s o f d e f i n i t i o n s i n both the b e r r y season and f a l l , w i t h %TA f o r d e f i n i t i o n s e t #1 b e i n g s i g n i f i c a n t l y l e s s than %TA f o r a l l o t h e r s e t s o f d e f i n i t i o n s i n both seasons. However, the l a r g e s t a b s o l u t e d i f f e r e n c e i n %TA among t h e s e t s o f d e f i n i t i o n s was s m a l l i n every season (2.28% f o r s p r i n g , 0.75% f o r e a r l y summer, 0.85% f o r b e r r y season, 1.38% f o r f a l l ) . A b s o l u t e d i f f e r e n c e s were r e l a t e d t o the t o t a l hours of a c t i v i t y data i n each season - the more hours o f a c t i v i t y data, the l e s s was the l a r g e s t a b s o l u t e d i f f e r e n c e - s u g g e s t i n g an averaging-out e f f e c t . Large changes i n %TA were p r e c l u d e d by the d i s t r i b u t i o n s o f a c t i v e and i n a c t i v e time a c r o s s bouts o f d i f f e r e n t d u r a t i o n s . Under the r u l e s used f o r c h a r t i n t e r p r e t a t i o n , t h e most f r e q u e n t l y o c c u r r i n g bout d u r a t i o n s were those < 5 32 min, but most o f the bears' time was spent i n bouts > 30 min ( F i g . 5a and 5b). Consequently, never more than about 15% o f the d a t a were a t r i s k o f been r e i n t e r p r e t e d by the program. Without independent e s t i m a t e s of a c t i v i t y (e.g., c o n c u r r e n t v i s u a l o b s e r v a t i o n s o f g r i z z l y bears and reco r d e d s i g n a l s ) t h e r e were no c r i t e r i a f o r s e l e c t i o n o f one s e t of d e f i n i t i o n s over another. However, g i v e n the s m a l l d i f f e r e n c e s between est i m a t e s of %TA, t h e o r i g i n a l c h a r t i n t e r p r e t a t i o n s were deemed a c c e p t a b l e and used f o r a l l subsequent a n a l y s e s . O v e r a l l %TA f o r a l l data combined was 55.4%. Data were not evenly d i s t r i b u t e d over the d i e l c y c l e but were b i a s e d t o daytime hours. A p p l y i n g equal importance t o each hour of the d i e l c y c l e r e s u l t e d i n an unweighted o v e r a l l %TA o f 53.7%. Unweighted est i m a t e s f o r sex-age c l a s s e s were 47.3% ( a d u l t males), 54.3% ( a d u l t f emales), 55.3% (subadult males), and 55.1% (subadult f e m a l e s ) . A t o t a l o f 44 complete 24-hour samples, r e p r e s e n t i n g 22% o f the e n t i r e d a t a s e t , were o b t a i n e d and used t o t e s t e f f e c t s o f sex, age, and i n d i v i d u a l bears. Only i n d i v i d u a l bears were s i g n i f i c a n t . E s t i m a t e s of %TA c a l c u l a t e d from complete 24- hour samples were s i m i l a r t o unweighted e s t i m a t e s c a l c u l a t e d from a l l d a t a combined (Table 3 ) . Ranges o f %TA f o r complete 24-hour samples were s i m i l a r t o those r e p o r t e d by H e c h t e l (1985; 15% - 74%). A l l sex-age c l a s s e s showed a d e f i n i t e t r e n d f o r %TA (weighted by hour of the day) t o i n c r e a s e t o a maximum LU F 5 < I UL o UJ u QC LU CL 100-1 80- 80- 70 60- 60- 40- £ 30- 20- • m LU LU > < z e LL o LU u DC LU 0. 100-1 80- 80- Bout Durations ZZ] <5 min ES3 >5 min,<10 min ED >10 min <15 min K B >15 min,<30 min >30 min SPRING EARLY BERRY SUMMER SEASON FALL SPRING EARLY BERRY SUMMER SEASON FALL F i g u r e 5. a) Percent o f t o t a l a c t i v e time as d i s t r i b u t e d between a c t i v e bouts o f d i f f e r e n t d u r a t i o n s and seasons, and b) p e r c e n t o f t o t a l i n a c t i v e time as d i s t r i b u t e d between i n a c t i v e bouts o f d i f f e r e n t d u r a t i o n s and seasons. oo oo 34 T a b l e 3. Means, s t a n d a r d e r r o r s o f t h e means, and ranges of p e r c e n t o f time a c t i v e by sex-age c l a s s , and o v e r a l l , c a l c u l a t e d from complete 24-hour samples on g r i z z l y b e a r s . Sex-acre c l a s s X SE n Rancre A d u l t males 48.2 7.0 5 26.4 - 65.3 A d u l t females 50.0 5.4 15 11.7 - 82.3 Subadult males 53.2 4.1 10 23.6 - 67.7 Subadult females 55.6 4.4 14 17.8 - 73.3 O v e r a l l 52.3 2.6 44 11.7 - 82.3 35 around J u l y and August f o l l o w e d by a marked d e c l i n e through September and October ( F i g . 6). L e v e l s o f %TA were s i m i l a r l y low i n A p r i l w i t h the e x c e p t i o n of s u b a d u l t females, however, r e c o r d e d data t o t a l s were s m a l l f o r both s u b a d u l t females and a d u l t males i n t h i s month (see T a b l e 1) • U s i n g complete 24-hour samples t o t e s t months (October was excluded due t o o n l y 1 o b s e r v a t i o n ) , i n d i v i d u a l s , and t h e i r i n t e r a c t i o n , r e s u l t e d i n s i g n i f i c a n t month and i n d i v i d u a l main e f f e c t s . A range t e s t on the p r e d i c t e d means f o r months r e s u l t e d i n o n l y A p r i l b e i n g s i g n i f i c a n t l y l e s s than August. Complete samples o b t a i n e d i n the months o f A p r i l , May and June may be b i a s e d towards i n a c t i v i t y (Table 4 ) . Bears e x h i b i t more f r e q u e n t movements i n these months (McLellan and Shackleton 1989) and f r e q u e n t l y went out o f range o f the r e c o r d e r s . Consequently, complete samples may o v e r r e p r e s e n t the b e h a v i o r of bears t h a t p e r i o d i c a l l y r e s t r i c t e d t h e i r a c t i v i t y t o l o c a l i z e d a reas. Annual a c t i v i t y p a t t e r n s by hour o f the day were s t r o n g l y bimodal f o r a l l sex-age c l a s s e s ( F i g . 7), and showed c o n s i s t e n t t r e n d s f o r low n o c t u r n a l l e v e l s o f %TA and a d i u r n a l minimum i n %TA around 1400 hours. S h i f t s i n peak l e v e l s o f %TA between 0700 - 0900 hours and between 2000 - 2100 hours were apparent between the d i f f e r e n t sex-age c l a s s e s . Times of s u n r i s e and sunset v a r y throughout t h e y e a r and data on d i f f e r e n t sex-age c l a s s e s were not e q u a l l y d i s t r i b u t e d throughout the months o f data c o l l e c t i o n . To PERCENT OF TIME ACTIVE PERCENT OF TIME ACTIVE H. (D o» o & n> c 3 i - r t r t o 0) t—' r t 0) H - W 9 - (D P> 0> 3 O Oi r t H - PJ < — (D 0, o C 3 M r t r t M) Hi (D O S H 01 l_< p) (0 ̂ - 01 (1) 01 e M O r t 9) t—1 9 O 0> C M I— 1  (D 0) 01 r t - (0 n o. O J= 3 M r t 0) M M) M (0 3 0) H-1 r t o> dt m o PERCENT OF TIME ACTIVE PERCENT OF TIME ACTIVE 37 T a b l e 4. Means, s t a n d a r d e r r o r s o f t h e means, and ranges o f p e r c e n t o f time a c t i v e by month, c a l c u l a t e d from complete 24-hour samples on g r i z z l y b e a r s . Month X SE n Rancre A p r i l 30.7 15.3 2 15.5 - 46.0 May 47.4 3.4 9 33.1 - 62.1 June 34.5 8.7 4 17.7 - 54.4 J u l y 69.0 5.2 5 55.7 - 82.3 August 62.3 3.7 11 26.4 - 71.8 September 50.1 4.9 12 11.7 - 73.3 October 42.8 _ _ _ 1 90- 2 F LL O 80 70 eo B0-| 40 30 20 ioH 0 l l Ii • • l 1 i i • i l l m Ik I I • i i i 1 •111 1 2 3 4 6 6 7 8 9 10 11 12 13 14 15 16 17 IB 192021222324 TIME OF DAY LU 2 F 90 80 70 80 80 40 30 M H 10 0 b J ri L i P i I J i • i l l i i I i i i i i i i 1 2 3 4 6 S l i I 111 III l i l i i iisllii it •••I i i i in H i 7 S 9 10 11 12 13 H 18 16 17 18 1920 21222324 TIME OF DAY 100 90 H 80 70H 80 60 40- 30- 20 10 0 11 * J III 1111 1 ! i i 2 3 4 6 8 7 8 9 K> 11 12 13 14 16 18 17 18 19 20 21 22 23 24 TIME OF DAY 100- 90 < LU 80 5 o J - 40 LU O 30 20-| 10 0 d l l lilii -J I » 1 i l l Jllllllllllfciiii • l • I i i I — Ml 1 2 3 4 8 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 TIME OF DAY F i g u r e 7. Annual p e r c e n t o f time a c t i v e by hour o f t h e day f o r a) a d u l t males, b) a d u l t females, c) subadult males, and d) s u b a d u l t females. For hours o f the day, 1 • 0000-0100; 2 = 0100-0200 e t c . U) 00 39 s t a n d a r d i z e the data w i t h r e s p e c t t o s o l a r events, f o u r d i e l p e r i o d s were d e f i n e d . Morning and evening ( c r e p u s c u l a r ) p e r i o d s were each 3 h l o n g and extended from 1.5 h b e f o r e , t o 1.5 h a f t e r , s u n r i s e and sunset r e s p e c t i v e l y . The i n t e r v e n i n g d u r a t i o n s between these c r e p u s c u l a r p e r i o d s were a s s i g n e d as d i u r n a l and n o c t u r n a l p e r i o d s ( F i g . 8 ) . In s p i t e o f the s t r o n g bimodal p a t t e r n s ( F i g . 7 ), o n l y a d u l t males showed a s t r o n g c r e p u s c u l a r p a t t e r n ( F i g . 8) w h i l e the remaining sex-age c l a s s e s showed s m a l l and i n c o n s i s t e n t d i f f e r e n c e s i n %TA between d i u r n a l and c r e p u s c u l a r p e r i o d s . A c t i v i t y peaks f o r a d u l t s males tended t o be narrow ( F i g . 7) w h i l e the o t h e r sex-age c l a s s e s d i s p l a y e d much wider peaks t h a t extended i n t o the d i u r n a l p e r i o d . Among o t h e r s t u d i e s , average a c t i v i t y measures are over v a r y i n g p o r t i o n s o f the s p r i n g , summer and f a l l . However, many e s t i m a t e s a re s i m i l a r t o those r e p o r t e d here. Roth (1983) found European brown bears t o be a c t i v e 47% o f the time as c a l c u l a t e d from a l l d a t a . For 7 data s e t s w i t h adequate data grouped by bear and month, he c a l c u l a t e d a mean a c t i v e l e v e l o f 53%. Roth and Huber (1986) r e p o r t e d average a c t i v e l e v e l s o f European brown bears o f 61% and 49% f o r a 2 - y e a r - o l d female and 4-y e a r - o l d male, r e s p e c t i v e l y . Combined means o f f u l l y a c t i v e b e h a v i o r and a s s o c i a t e d s t a t i o n a r y a c t i v e b e h a v i o r f o r g r i z z l i e s on the e a s t f r o n t o f the Rockies (Aune and S t i v e r s 1983), r e s u l t e d i n an esti m a t e o f 11.9 h of a c t i v i t y p e r 24-hour c y c l e (49.6%). Aune and Kasworm (1989) concluded t h a t g r i z z l i e s on the e a s t vQ C CD CO PERCENT OF TIME ACTIVE PERCENT OF TIME ACTIVE 3 3 PJ fl> 01 - T3 fl> 0 ^ — o CD cn 3 £ ft cr ca o & M> c M rt rt H-3 CD P> n> o 01 ft - H - <J PJ (D 3 & er & — o. 01 (D cr pj *rJ CL CD H" H - rt O 0< H) CD Hi o 3 PJ M (D PJ 01 ^ P> O. 3 PJ H-1 CD 01 PJ PERCENT OF TIME ACTIVE PERCENT OF TIME ACTIVE 41 f r o n t o f the Rockies were i n v o l v e d i n 10 - 15 h o f v i g o r o u s a c t i v i t y over a 24-hour p e r i o d (41.6 - 62.5%). S c h l e y e r (1983) found g r i z z l i e s i n Yellowstone t o e x h i b i t a y e a r l y average a c t i v e l e v e l o f about 8 - 12 h per day (33.3 - 50.0%). H a r t i n g (1985) a l s o worked i n Yellowstone and d i d not p r e s e n t an average a c t i v i t y e s t i m a t e , however, the p r o b a b i l i t y of bears been a c t i v e averaged a c r o s s the months of h i s study was 0.61 ( c a l c u l a t e d from data o f F i g . 10, H a r t i n g 1985). From d i r e c t o b s e r v a t i o n a l s t u d i e s o f g r i z z l i e s i n n o r t h e r n A l a s k a , annual a c t i v e e s t i m a t e s were 77.5% ( c a l c u l a t e d from data o f T a b l e 1, P h i l l i p s 1987), 64.0% (Gebhard 1982), and 40% ( c a l c u l a t e d from data o f H e c h t e l 1985). Most o b s e r v a t i o n s made by H e c h t e l (1985) were o b t a i n e d p r i o r t o mid-June. For a female g r i z z l y observed from s p r i n g t o f a l l H e c h t e l (1985) r e p o r t e d an a c t i v i t y l e v e l o f 55%. The g e n e r a l p a t t e r n o f v a r i a t i o n i n a c t i v i t y over months r e p o r t e d here, i s s i m i l a r t o t h a t found by H a r t i n g (1985) f o r Yellowstone g r i z z l i e s where a c t i v e l e v e l s i n c r e a s e d from May through t o a peak i n J u l y , and then d e c l i n e d through t o September. High d a i l y a c t i v e l e v e l s i n J u l y and August c o i n c i d e w i t h the occurrence o f hyperphagic b e h a v i o r by g r i z z l y bears (Watts and J o n k e l 1988). G a r s h e l i s and P e l t o n (1980) found a s i m i l a r p a t t e r n f o r b l a c k bears i n the Great Smoky Mountains. S t u d i e s on g r i z z l y and b l a c k bears support a g e n e r a l t r e n d o f low d a i l y 42 a c t i v e l e v e l s i n p o s t - and pre-denning months (e.g., S c h l e y e r 1983; Amstrup and Beecham 1976). Bimodal a c t i v i t y p a t t e r n s by hour of the day or d i e l p e r i o d a re commonly r e p o r t e d i n the l i t e r a t u r e f o r both g r i z z l i e s (Aune and Kasworm 1989; H a r t i n g 1985; S c h l e y e r 1983; Roth 1983) and b l a c k bears (Ayres e t a l . 1986; G a r s h e l i s and P e l t o n 1980). The main d i f f e r e n c e among s t u d i e s (and among bears w i t h i n s t u d i e s ) tends t o be whether bears a r e r e l a t i v e l y more a c t i v e d u r i n g the n o c t u r n a l hours s e p a r a t i n g the bimodal peaks o r d u r i n g the d i u r n a l hours. Such v a r i a t i o n i n a c t i v i t y p a t t e r n s may be a product o f s e v e r a l f a c t o r s i n c l u d i n g f o r a g i n g b e h a v i o r (Ayres e t a l . 1986; H a r t i n g 1985) and l e v e l o f human d i s t u r b a n c e (Aune and Kasworm 1989; Roth 1983). ^ CONCLUSIONS The consequences o f p o t e n t i a l e r r o r s i n a c t i v i t y c l a s s i f i c a t i o n appear t o be s m a l l based on the assumption t h a t the l o n g e r the minimum d u r a t i o n r e q u i r e d f o r r e c o g n i t i o n the more l i k e l y t he bout i s t o be c l a s s i f i e d c o r r e c t l y . Under the bout d e f i n i t i o n s examined, d u r a t i o n s o f a c t i v e and i n a c t i v e p u l s e p a t t e r n s l e s s than the minimums r e c o g n i z e d , accounted f o r a s m a l l p e r c e n t o f the be a r s ' time. The i n f l u e n c e o f a b i a s t o a c t i v e bouts i n the c h a r t i n t e r p r e t a t i o n r u l e s i n t r o d u c e d by r e c o g n i t i o n o f bouts down t o > 1 min a l s o appears minimal. Short a c t i v e bouts occur w i t h the g r e a t e s t frequency i n the data but t h e i r i n f l u e n c e 43 on e s t i m a t e s of %TA i s minimal because the bouts are weighted i n d i r e c t p r o p o r t i o n t o t h e i r d u r a t i o n . Systematic e r r o r s i n c l a s s i f i c a t i o n u s i n g time-sampling, l i k e l y would have a g r e a t e r e f f e c t because each sample i s weighted e q u a l l y . I d e a l l y , s t a t i s t i c a l comparisons of a c t i v i t y budgets sh o u l d be based on complete 24-hour samples o f a c t i v i t y t o c a p t u r e complete d i e l c y c l e s and t o s t a n d a r d i z e the d u r a t i o n o f time t h a t a sample encompasses. However, such samples are r a r e i n the data and are p o o r l y d i s t r i b u t e d a c r o s s months and i n d i v i d u a l s . A n a l y s e s based on complete 24-hour samples were unbalanced and s u f f e r e d from m i s s i n g c e l l s . A l l a l p h a l e v e l s , as w e l l as assumptions o f no c o r r e l a t i o n s between means f o r range t e s t s based on s t u d e n t i z e d ranges, may be compromised ( G r i e g and B j e r r i n g 1978). In a study such as t h i s one, d e t e r m i n a t i o n o f what c o n s t i t u t e s an o b s e r v a t i o n i s not s t r a i g h t f o r w a r d . Time-sampling o f the c h a r t s and r e t a i n i n g each sample as an o b s e r v a t i o n would have r e s u l t e d i n a sample s i z e o f s e v e r a l thousands. However, the s e are u n l i k e l y t o be independent. On the o t h e r hand, t h e use o f 24-hour samples r e s t r i c t s s t a t i s t i c a l t e s t s t o a s m a l l p o r t i o n of the t o t a l d ata base. A n a l y s e s o f %TA w i t h i n and between seasons are p r e s e n t e d l a t e r and r e l y on a compromise between the 2 above noted extremes i n o b s e r v a t i o n s . General a c t i v i t y measures p r e s e n t e d here a r e w e l l w i t h i n the range o f r e s u l t s from o t h e r s t u d i e s . Comparisons 44 w i t h o t h e r s t u d i e s and e x p l o r a t i o n of the s e n s i t i v i t y of %TA t o a l t e r n a t i v e d e f i n i t i o n s of bouts do not r e p l a c e v i s u a l v e r i f i c a t i o n o f p u l s e mode p a t t e r n s and a c t u a l b e h a v i o r , but do s t r e n g t h e n t h e assumption t h a t bear a c t i v i t y has been adequately q u a n t i f i e d by the methods I used. 45 LITERATURE CITED Altmann, J . 1974. O b s e r v a t i o n a l study o f b e h a v i o r : sampling methods. Behaviour 49:227-265. Amstrup, S. C., and J . Beecham. 1976. A c t i v i t y p a t t e r n s of r a d i o - c o l l a r e d b l a c k bears i n Idaho. J . W i l d l . Manage. 40:340-348. Aune, K., and T. S t i v e r s . 1983. Rocky Mountain f r o n t g r i z z l y bear m o n i t o r i n g and i n v e s t i g a t i o n . Mont. Dep. F i s h , W i l d l . and Parks. Helena, Montana. 180 pp. Aune, K., and W. Kasworm. 1989. F i n a l r e p o r t : e a s t f r o n t g r i z z l y bear study. Mont. Dep. F i s h , W i l d l . and Parks. Helena, Montana. 332 pp. Ayers, L. E., L. S. Chow, and D. M. Graber. 1986. B l a c k bear a c t i v i t y p a t t e r n s and human induced m o d i f i c a t i o n s i n Sequoia N a t i o n a l Park. I n t . Conf. Bear Res. and Manage. 6:151-1654. B j a r v a l l , A., and F. Sandegren. 1987. E a r l y e x p e r i e n c e s w i t h the f i r s t radio-marked brown bears i n Sweden. I n t . Conf. Bear Res. and Manage. 7:9-12. Cederlund, G. 1981. D a i l y and s e a s o n a l a c t i v i t y p a t t e r n of roe deer i n a b o r e a l h a b i t a t . V i l t r e v y 11:315-353. Cederlund, G., and P. A. Lemnell. 1980. A c t i v i t y r e c o r d i n g o f r a d i o - t a g g e d animals. B i o t e l e m e t r y P a t i e n t Monitg. 7:206-214. Clevenger, A. P., F. J . Purroy, and M. R. P e l t o n . 1990. Movement and a c t i v i t y p a t t e r n s o f a European brown bear i n t h e C a n t a b r i a n Mountains, Spain. I n t . Conf. Bear. Res. and Manage. 8:205-211. G a r s h e l i s , D. L., and M. R. P e l t o n . 1980. A c t i v i t y o f b l a c k bears i n the Great Smoky Mountains N a t i o n a l Park. J . Mammal. 61:8-19. 46 G a r s h e l i s , D. L., H. B. Q u i g l e y , C. R. V i l l a r r u b i a , and M. R. P e l t o n . 1982. Assessment of t e l e m e t r i c motion sensors f o r s t u d i e s o f a c t i v i t y . Can. J . Z o o l . 60:1800- 1805. Gebhard, J . G. 1982. Annual a c t i v i t i e s and b e h a v i o r of a g r i z z l y bear (Ursus a r c t o s ) f a m i l y i n n o r t h e r n A l a s k a . M.Sc. T h e s i s . Univ. A l a s k a , F a i r b a n k s , A l a s k a . 218 pp. G r i e g , M., and J . B j e r r i n g . 1978. UBC GENLIN - a g e n e r a l l e a s t squares a n a l y s i s o f v a r i a n c e program. Computing Centre. Univ. of B r i t i s h Columbia, Vancouver, B r i t i s h Columbia. 48 pp. H a r t i n g , A. L. 1985. R e l a t i o n s h i p s between a c t i v i t y p a t t e r n s and f o r a g i n g s t r a t e g i e s of Yellowstone g r i z z l y bears. M.Sc. T h e s i s , Mont. S t a t e Univ., Bozeman, Montana. 103 pp. H e c h t e l , J . L. 1985. A c t i v i t y and food h a b i t s of b a r r e n - ground g r i z z l y bears i n A r c t i c A l a s k a . M.Sc. T h e s i s . Univ. Montana, M i s s o u l a , Montana. 74 pp. H i c k s , C. R. 1982. Fundamental concepts i n the d e s i g n o f experiments. 3rd edn. H o l t , R i n e h a r t and Winston, New York, New York. 425 pp. Jacobsen, N. K., and A. D. Wiggins. 1982. Temporal and p r o c e d u r a l i n f l u e n c e s on a c t i v i t y e s t i m a t e d by time- sampling. J . W i l d l . Manage. 46:313-324. Lindzey, F. G., and E. C. Meslow. 1977. Home range and h a b i t a t use by b l a c k bears i n southwestern Washington. J . W i l d l . Manage. 41:413-425. M c L e l l a n , B. N., and D. M. Shackleton. 1989. G r i z z l y bears and r e s o u r c e - e x t r a c t i o n i n d u s t r i e s : h a b i t a t displacement i n response t o s e i s m i c e x p l o r a t i o n , timber h a r v e s t i n g and road maintenance. J . A p p l . E c o l . 26:371- 380. P h i l l i p s , M. K. 1987. Behavior and h a b i t a t use of g r i z z l y bears i n n o r t h e a s t e r n A l a s k a . I n t . Conf. Bear Res. and Manage. 7:159-167. 47 Roth, H. U. 1983. D i e l a c t i v i t y o f a remnant p o p u l a t i o n o f European brown bears. I n t . Conf. Bear Res. and Manage. 5:223-229. Roth, H. U., and D. Huber. 1986. D i e l a c t i v i t y o f brown bears i n P l i t v i c e Lakes N a t i o n a l Park, Y u g o s l a v i a . I n t . Conf. Bear Res. and Manage. 6:177-181. S c h l e y e r , B. 0. 1983. A c t i v i t y p a t t e r n s of g r i z z l y bears i n the Yellowstone ecosystem and t h e i r r e p r o d u c t i v e b e h a v i o r , p r e d a t i o n and use o f c a r r i o n . M.Sc. T h e s i s , Mont. S t a t e Univ., Bozeman, Montana. 13 0 pp. S o k a l , R. R., and F. J . R o h l f . 1981. Biometry. 2nd edn. W. H. Freeman and Co. New York, New York. 859 pp. Smith, T. R. 1986. A c t i v i t y and b e h a v i o r o f denned b l a c k bears i n the lower M i s s i s s i p p i R i v e r v a l l e y . I n t . Conf. Bear Res. and Manage. 6:137-143. So r o k i n , P. A., and C. Q. Berger. 1939. Time-budgets o f human be h a v i o r . Harvard U n i v e r s i t y Press, Cambridge, Massachusetts. 204 pp. Watts, P. D., and C. J o n k e l . 1988. E n e r g e t i c c o s t o f w i n t e r dormancy i n g r i z z l y bear. J . W i l d l . Manage. 52:654-656. 48 CHAPTER 3: BOUT LENGTHS INTRODUCTION Time-energy budgets determine an organism's e n e r g e t i c s t a t u s . C o a r s e - g r a i n e d a c t i v i t y budgets which r e s o l v e o n l y a c t i v e and i n a c t i v e b e h a v i o r a l s t a t e s l a c k i n f o r m a t i o n c o n c e r n i n g the e n e r g e t i c c o s t s o r g a i n s o f time spent i n e i t h e r b e h a v i o r . D e s p i t e t h i s l i m i t a t i o n , broad e x p e c t a t i o n s o f how g r i z z l y bears manage t h e i r time may be d e r i v e d from t h e o r e t i c a l c o n s i d e r a t i o n s , and from e m p i r i c a l o b s e r v a t i o n s gained from i n t e r s p e c i f i c s t u d i e s . In t h i s c h apter, the emphasis i s on the l e n g t h s of both a c t i v e and i n a c t i v e bouts. Although t o t a l time a c t i v e w i l l be d e a l t w i t h e x p l i c i t l y i n a l a t e r chapter, i t i s a l s o an important determinant o f bout l e n g t h s because changes i n t o t a l time a c t i v e t r a n s l a t e i n t o changes i n a c t i v e bout d u r a t i o n s , i n f r e q u e n c i e s (and hence, changes i n i n a c t i v e bout l e n g t h s ) , o r i n both. T h e o r e t i c a l treatments o f time a l l o c a t i o n a re r a r e ( B u n n e l l and G i l l i n g h a m 1985; Herbers 1981). However, energy a c q u i s i t i o n i s a fundamental component o f time-budget t h e o r y (Herbers 1981). The t o t a l time bears spend f o r a g i n g ( s e a r c h i n g and consuming food) l i k e l y depends on i n d i v i d u a l s p e c i f i c f a c t o r s (weight, sex, age, r e p r o d u c t i v e s t a t u s ) t h a t determine e n e r g e t i c requirements and c o n s t r a i n t s , and on environmental f a c t o r s t h a t l i m i t the i n d i v i d u a l ' s o p t i o n s f o r r e s o l v i n g energy problems (see review i n B u n n e l l and 49 G i l l i n g h a m 1985). F o r a g i n g bout l e n g t h s may be viewed as a f u n c t i o n o f gut s i z e , i n g e s t i o n and d i g e s t i o n r a t e s (Bunnell and G i l l i n g h a m 1985). G e n e r a l l y , most o f the a c t i v e time t h a t a mammal spends i s devoted t o f o r a g i n g ( B u n n e l l and Harestad 1989), w h i l e most n o n f o r a g i n g time i s spent r e s t i n g (Herbers 1981). Consequently, t o t a l time a c t i v e s h o u l d r e l a t e b r o a d l y t o f a c t o r s d e t e r m i n i n g t o t a l time spent f o r a g i n g , and both a c t i v e and i n a c t i v e bout l e n g t h s s h o u l d r e l a t e t o f a c t o r s d e t e r m i n i n g f o r a g i n g bout l e n g t h s and f o r a g i n g frequency. The importance o f body weight i s g e n e r a l l y viewed from an i n t e r s p e c i f i c p e r s p e c t i v e . As body weight i n c r e a s e s , s e v e r a l p h y s i c a l r e l a t i o n s h i p s between an organism and i t s environment change, but a t d i f f e r e n t r a t e s (Demment 1983). T h e r e f o r e , animals of d i f f e r e n t weights are r e q u i r e d t o respond t o t h e i r environment i n d i f f e r e n t ways (Demment 1983). Among s p e c i e s , one s i g n i f i c a n c e o f b e i n g h e a v i e r i s t h a t requirements f o r t o t a l d a i l y e n e r g e t i c i n t a k e i n c r e a s e but a t a d e c r e a s i n g r a t e (Demment 1983) because energy requirements s c a l e t o m e t a b o l i c weight ( K l e i b e r 1975, p. 202). Gut c a p a c i t y , however, i n c r e a s e s near l i n e a r l y w i t h body weight (Demment 1983). These g e n e r a l r e l a t i o n s h i p s w i t h body weight apply w i t h i n s p e c i e s as w e l l , a l t h o u g h the a c t u a l r a t e s may be somewhat d i f f e r e n t (Feldman and McMahon 1983; Demment 1983; Huesner 1982). The f u n c t i o n a l consequence o f t h i s r e l a t i o n s h i p between gut s i z e and m e t a b o l i c requirement i s t h a t s m a l l e r i n d i v i d u a l s must 50 e x h i b i t h i g h e r r a t e s of passage than l a r g e r i n d i v i d u a l s t o meet t h e i r energy requirements (Demment 1983). W i t h i n g r i z z l y bears, weight i s c o v a r i a t e w i t h both sex and age. A d u l t s are l a r g e r than s u b a d u l t s , males are l a r g e r than females. Based on a b s o l u t e e n e r g e t i c requirements d i c t a t e d by weight, and assuming an i d e n t i c a l f o r a g e type a c r o s s d i f f e r e n t c l a s s e s o f bears, a d u l t males may be expected t o spend more t o t a l time f o r a g i n g than o t h e r sex- age c l a s s e s . However, a d u l t males may, f o r example, reduce t h e i r t o t a l f o r a g i n g time a) by b e i n g l e s s s e l e c t i v e i n f o r a g e components consumed (a s t r a t e g y a v a i l a b l e t o them due t o t h e r e l a t i o n s h i p between gut c a p a c i t y and m e t a b o l i c requirement), b) by e x p r o p r i a t i n g the most p r o f i t a b l e f o r a g i n g patches f o r themselves (e.g., Egbert and Stokes 1976; Stonorov and Stokes 1972), o r c) by f o r a g i n g more i n t e n s i v e l y (Bunnell and G i l l i n g h a m 1985). The o t h e r sex- age c l a s s e s have a d d i t i o n a l e n e r g e t i c requirements t o those determined by weight alone. A d u l t females must contend w i t h t h e i n c r e a s e d e n e r g e t i c and n u t r i t i v e demands o f g e s t a t i o n and l a c t a t i o n ( L l o y d e t a l . 1978). Subadults have i n c r e a s e d e n e r g e t i c and n u t r i t i v e requirements f o r growth ( L l o y d e t a l . 1978), and are p o t e n t i a l l y hampered by f o r a g i n g i n e f f i c i e n c i e s due t o i n e x p e r i e n c e (Bunnell and G i l l i n g h a m 1985) o r t o t h e i r s m a l l e r s i z e . Gebhard (1982) noted t h a t o f 2 g r i z z l y y e a r l i n g s i n a f a m i l y group t h a t he observed throughout t h e i r a c t i v e year, the s m a l l e r female y e a r l i n g was l e s s e f f i c i e n t than was her male s i b l i n g , and both 51 y e a r l i n g s were l e s s e f f i c i e n t than t h e i r mother when f o r a g i n g f o r important but p h y s i c a l l y d i f f i c u l t t o e x t r a c t foods such as r o o t s and ground s q u i r r e l s . P r e d i c t i o n s o f t o t a l time a c t i v e , t h e r e f o r e , must i n c o r p o r a t e sex, age and r e p r o d u c t i v e s t a t u s d i f f e r e n c e s i n energy requirements, f o r a g i n g s t r a t e g i e s and a b i l i t i e s . An i n d i v i d u a l bear's p a r t i t i o n i n g of t o t a l a c t i v e time i n t o a sequence of a c t i v e bouts t h a t a l t e r n a t e w i t h i n a c t i v e bouts, w i l l be b r o a d l y a f u n c t i o n o f the r a t e a t which the i n d i v i d u a l f i l l s and empties i t s gut. I n g e s t i o n r a t e s w i l l depend on s e a r c h time, on components of h a n d l i n g time such as p u r s u i n g and subduing prey, on b i t e r a t e , on b i t e s i z e (the amount o f food t h a t can be taken i n each b i t e as determined by forage c h a r a c t e r i s t i c s ) , and a l s o on p h y s i c a l mouth s i z e which s e t s an a b s o l u t e upper l i m i t on b i t e s i z e . Under the assumption t h a t mouth s i z e s c a l e s t o body s i z e i n a f a s h i o n s i m i l a r t o gut c a p a c i t y , d i f f e r e n t s i z e d bears f e e d i n g on the same for a g e s h o u l d be a b l e t o f i l l t h e i r gut a t the same r a t e , p r o v i d e d t h a t b i t e s i z e i s not l i m i t i n g . However, f o r some food types such as b e r r i e s t h a t a r e d i s t r i b u t e d s i n g l y o r i n s m a l l c l u s t e r s , b i t e s i z e i s e s s e n t i a l l y independent of the s i z e o f the bear, so s m a l l bears s h o u l d f i l l t h e i r gut f a s t e r , u n l e s s l a r g e r bears can compensate by i n c r e a s i n g t h e i r b i t e r a t e . For bears o f d i f f e r e n t s i z e s on the same forage type, the s i g n i f i c a n c e o f b e i n g s m a l l e r w i l l be expressed i n a requirement f o r more f o r a g i n g bouts due t o h i g h e r passage 52 r a t e s needed t o meet t h e i r m e t a b o l i c requirements. The c o v a r i a t e n ature o f s i z e and age i n d i c a t e s t h a t s m a l l e r bears w i l l have a d d i t i o n a l e n e r g e t i c requirements f o r growth t h a t s h o u l d i n t e n s i f y the d i f f e r e n t i a l i n r e q u i r e d f o r a g i n g bouts. Smaller, younger bears may o f f s e t an i n c r e a s e i n the number o f f o r a g i n g bouts r e q u i r e d , by s e l e c t i v e l y f o r a g i n g on h i g h e r q u a l i t y components o f the forage (a s t r a t e g y a v a i l a b l e t o s m a l l e r animals w i t h a b s o l u t e l y lower e n e r g e t i c r e q u i r e m e n t s ) , perhaps a t the c o s t o f l o n g e r f o r a g i n g bouts. A s i m i l a r requirement f o r more o r l o n g e r f o r a g i n g bouts p e r u n i t time i s expected when a d u l t females i n c u r r e p r o d u c t i v e c o s t s , e s p e c i a l l y l a c t a t i o n . The above arguments have been formulated under the r e s t r i c t i o n o f i d e n t i c a l f o r a g e types a c r o s s sex-age and r e p r o d u c t i v e c l a s s e s o f bea r s . W i t h i n seasons t h i s may be g e n e r a l l y t r u e . However, u n l i k e many s p e c i e s (e.g., h e r b i v o r e s ) t h a t p e r s i s t e n t l y consume s i m i l a r f o r a g e s p e c i e s , bears e x h i b i t dramatic s h i f t s i n food h a b i t s throughout the annual c y c l e (Bunnell and Hamilton 1983; Pearson 1975). V a r i a t i o n i n food types i s expected t o i n f l u e n c e both t o t a l time a c t i v e and the p a r t i t i o n i n g o f time i n t o a c t i v e and i n a c t i v e bouts through s e a r c h i n g and h a n d l i n g times. The p o t e n t i a l f o r d i f f e r e n t sex-age o r r e p r o d u c t i v e c l a s s e s t o i n c r e a s e o r decrease fo r a g e s e l e c t i v i t y i s a l s o l i k e l y c o n s t r a i n e d d i f f e r e n t i a l l y among seasons. 53 P r e d i c t i n g t o t a l time a c t i v e , through i n t e g r a t i o n o f m e t a b o l i c requirements determined by weight, age, and r e p r o d u c t i v e s t a t u s , w i t h the i n f l u e n c e s o f forage type, f o r a g i n g s t r a t e g y , p h y s i c a l a b i l i t y , and t h e c a p a c i t y o f t h e gut i n r e l a t i o n t o m e t a b o l i c requirements i s a complex t a s k . Many o t h e r f a c t o r s (e.g., a v a i l a b l e d a y l i g h t , mating a c t i v i t i e s , weather) l i k e l y e x e r t important i n f l u e n c e s . Determining a p r i o r i how i n d i v i d u a l s p a r t i t i o n t o t a l time a c t i v e i n t o d i s c r e t e packages and i n t e r s p e r s e these bouts w i t h d i s c r e t e packages of i n a c t i v i t y i s perhaps i m p o s s i b l e . My i n t e n t was not t o generate a s e t o f t e s t a b l e p r e d i c t i o n s through d e d u c t i o n , but r a t h e r t o p r o v i d e a t h e o r e t i c a l framework from which e x p e c t a t i o n s o f d i f f e r e n c e s i n bout d u r a t i o n s c o u l d be generated. A n a l y s e s between sex-age c l a s s e s throughout the ye a r may i n d i c a t e g e n e r a l d i f f e r e n c e s i n how bears o f d i f f e r e n t sexes and ages respond t o t h e i r environment. I f food type i n f l u e n c e d bout l e n g t h s , t h i s may be r e v e a l e d through comparisons conducted among seasons. Under the assumption t h a t w i t h i n any season a l l bears f o r a g e d on s i m i l a r foods, w i t h i n season d i f f e r e n c e s i n bout l e n g t h s s h o u l d r e f l e c t how sex-age o r r e p r o d u c t i v e c l a s s e s packaged f o r a g i n g and r e s t i n g t o r e s o l v e t h e i r e n e r g e t i c requirements and c o n s t r a i n t s . I f d i f f e r e n t food types i n f l u e n c e d t h i s packaging d i f f e r e n t l y f o r s p e c i f i c c l a s s e s o f bears, t h i s may be b r o a d l y i n d i c a t e d by a l a c k o f c o n s i s t e n t t r e n d s a c r o s s seasons. 54 My s p e c i f i c o b j e c t i v e s were t o : 1) as s e s s whether sex- age c l a s s e s o f bears d i f f e r e d i n i n a c t i v e and a c t i v e bout d u r a t i o n s on an annual b a s i s ; 2) assess whether i n a c t i v e and a c t i v e bout d u r a t i o n s pooled f o r a l l bears v a r i e d as a f u n c t i o n o f season; and 3) t e s t w i t h i n seasons f o r d i f f e r e n c e s i n i n a c t i v e and a c t i v e bout d u r a t i o n s among bears o f d i f f e r e n t sex, age and r e p r o d u c t i v e s t a t u s . METHODS Ana l y s e s o f a c t i v i t y bout d u r a t i o n s were conducted on c h a r t r e c o r d e d a c t i v i t y data o f g r i z z l y b e a r s . A c t i v e bouts were d e f i n e d as p u l s e mode p a t t e r n s c o n s i s t e n t w i t h the a c t i v e s t a t e t h a t had a minimum d u r a t i o n o f 1 min. I n a c t i v e bouts were d e f i n e d as p a t t e r n s c o n s i s t e n t w i t h the i n a c t i v e s t a t e t h a t had a minimum d u r a t i o n o f 2.5 min. Only complete bouts o f each type were used i n the a n a l y s e s . A c t i v e and i n a c t i v e bouts i n p r o g r e s s a t the b e g i n n i n g o r end o f a r e c o r d i n g s e s s i o n , o r those i n t e r r u p t e d by bouts a s s i g n e d as unknown (due t o m i s s i n g data) were excluded. Separate, but i d e n t i c a l a n a l y s e s were conducted f o r a c t i v e bouts and i n a c t i v e bouts. A n a l y s e s W i t h i n Seasons For a n a l y s e s conducted on each o f the 4 se a s o n a l data s e t s , l i n e a r models o f sources o f v a r i a t i o n were d e r i v e d under two approaches: 1) a n e s t e d - f a c t o r i a l model w i t h sex and age c l a s s e s as c r o s s e d main e f f e c t s and i n d i v i d u a l bears 55 neste d w i t h i n sex-age c l a s s combinations, and 2) a f u l l y h i e r a r c h i c a l model w i t h the h i g h e s t l e v e l ( p o p u l a t i o n component) composed of 6 treatments (females w i t h cubs, females w i t h y e a r l i n g s , females without o f f s p r i n g , a d u l t males, s u b a d u l t males, and s u b a d u l t f e m a l e s ) , w i t h i n d i v i d u a l bears nested w i t h i n the treatments. E x p l o r a t o r y a n a l y s e s of the data i n d i c a t e d t h a t the d i s t r i b u t i o n s o f both a c t i v e and i n a c t i v e bouts were skewed t o the r i g h t and l e p t o k u r t o t i c ( g l and g2 both p o s i t i v e ; S o kal and R o h l f 1981, p. 117). T r a n s f o r m a t i o n s t o n o r m a l i t y were attempted by u s i n g powers < 1 (Velleman and H o a g l i n 1981, p. 48) and ass e s s e d w i t h L i l l i e f o r s • s t e s t (P = 0.05; W i l k i n s o n 1989, p. 604). No s u i t a b l e t r a n s f o r m a t i o n s were found and nonparametric a l t e r n a t i v e s were u t i l i z e d . However, nonparametric t e c h n i q u e s are g e n e r a l l y awkward when a p p l i e d t o complex models (Conover 1971, p. 274) and may not l e n d themselves t o such a n a l y s e s . Nonparametric analogs t o one-way a n a l y s i s o f v a r i a n c e ( K r u s k a l - W a l l i s t e s t s ; Conover 1971, p. 256) were used t o t e s t each bout type w i t h i n season, w i t h i n d i v i d u a l bears as l e v e l s o f the main e f f e c t o f i n t e r e s t . To extend the s e t of c o n c l u s i o n s drawn from K r u s k a l - W a l l i s t e s t s , nonparametric m u l t i p l e comparisons (Gibbons 1985, p. 181; Dunn 1964) which permit simultaneous s t a t i s t i c a l i n f e r e n c e s were used. The advantage of t h i s procedure was t h a t i n d i v i d u a l s r e p r e s e n t i n g a l e v e l o f an e f f e c t (e.g., a sex or age c l a s s ) c o u l d be p o o l e d and 56 compared t o o t h e r p o o l e d i n d i v i d u a l s r e p r e s e n t i n g another l e v e l o f the e f f e c t . C o n t r a s t s were developed t o t e s t e f f e c t s i n accordance w i t h the s t r u c t u r e o f the data o u t l i n e d i n t h e above models. Adjustment o f the alpha l e v e l f o r each t e s t o f a c o n t r a s t , i n accordance w i t h the number of c o n t r a s t s t e s t e d w i t h i n each s e a s o n a l data s e t , encouraged parsimony i n the number of t e s t s performed. T h e r e f o r e , a subset o f c o n t r a s t s t h a t p e r m i t t e d e x p l o r a t i o n of p o t e n t i a l d i f f e r e n c e s as o u t l i n e d i n the i n t r o d u c t i o n was developed. An experimentwise e r r o r r a t e o f 0.10 was maintained f o r each s e a s o n a l a n a l y s i s . Annual and Among Seasons A n a l y s e s Comparisons o f a c t i v e and i n a c t i v e bout l e n g t h s among sex-age c l a s s e s on an annual b a s i s were performed by p o o l i n g a l l d a t a w i t h i n each sex-age c l a s s by bout type. D i f f e r e n c e s among seasons were e x p l o r e d by p o o l i n g a l l data w i t h i n each season by bout type. As w i t h a n a l y s e s conducted w i t h i n seasons, the d i s t r i b u t i o n s o f bout l e n g t h s were skewed t o the r i g h t and l e p t o k u r t o t i c . A n a l y s e s d i d not extend beyond the e x p l o r a t o r y data a n a l y s i s procedure o f notched box p l o t s ( W i l k i n s o n 1988, p. 206; M c G i l l e t a l . 1978) which p r o v i d e d comparisons of h e u r i s t i c v a l u e . Box p l o t s p r o v i d e v i s u a l summaries o f data w i t h the ends o f the box r e p r e s e n t i n g the q u a r t i l e s and the l i n e b i s e c t i n g the box r e p r e s e n t i n g the median. Notched box p l o t s enable comparisons between 2 sample medians a t approximately 95% 57 c o n f i d e n c e ( M c G i l l e t a l . 1978). However, the e r r o r r a t e i s not a d j u s t e d f o r m u l t i p l e comparisons (Velleman and H o a g l i n 1981, p. 74). The p r a c t i c a l consequence o f t h i s i s t h a t any 2 box p l o t s w i t h o v e r l a p p i n g c o n f i d e n c e i n t e r v a l s w i l l never be s i g n i f i c a n t l y d i f f e r e n t i f p a i r w i s e e r r o r r a t e s are a d j u s t e d i n o r d e r t o m a i n t a i n the experimentwise e r r o r r a t e a t 0.05. However, 2 box p l o t s w i t h n o n - o v e r l a p p i n g c o n f i d e n c e i n t e r v a l s may not be d i f f e r e n t i f such adjustments are made. RESULTS The use of complete bouts i n these a n a l y s e s p r o b a b l y b i a s e d r e s u l t s towards bouts o f s h o r t e r d u r a t i o n . Longer bouts were more l i k e l y t o be i n t e r r u p t e d by m i s s i n g data due t o s i g n a l i n t e r f e r e n c e , t o frequency d r i f t , o r t o the bear moving behind o b s t a c l e s . An e x p e c t a t i o n t h a t a lower percentage o f a c t i v e bouts than i n a c t i v e bouts would be complete due t o the b e a r s 1 movements was o n l y weakly expressed (77% o f a l l a c t i v e bouts were complete v e r s u s 79% o f a l l i n a c t i v e b o u t s ) . However, complete i n a c t i v e bouts accounted f o r 70.3% o f the t o t a l r e c o r d e d i n a c t i v e time, w h i l e complete a c t i v e bouts accounted f o r o n l y 54.1% o f the t o t a l r e c o r d e d a c t i v e time. Percent of time a c t i v e c a l c u l a t e d from complete bout data tended t o be h i g h e r than t h a t c a l c u l a t e d from a l l a v a i l a b l e data i n t h e s p r i n g but lower i n t h e remaining 3 seasons (Table 5 ) . T a b l e 5. Percent of time a c t i v e by p o p u l a t i o n component and season as determined by complete a c t i v e and i n a c t i v e bouts (columns under C) and as determined by a l l a v a i l a b l e data (columns under A). Samples s i z e s of complete bouts are i n brack e t s . P o p u l a t i o n E a r l y Berry Component S p r i n g Summer Season F a l l C A C A C A C A A l l A d u l t Females 51.0 (455) 47.7 47.6 (1639) 56. 6 54.1 (544) 65. 3 39.5 (555) 47.1 b w i t h COYS 38.5 (119) 29.1 42.9 (475) 41. 0 — — 12.6 (8) 86.8 w i t h y e a r l i n g s — — 64.3 (96) 81. 5 67.3 (66) 76. 4 54.0 (188) 59.6 alone or with 2-year-olds 55.1 (336) 55.8 48.0 (1068) 56. 1 52.3 (478) 61. 9 33.5 (359) 31.6 A d u l t Males 49.2 (130) 33.2 45.9 (971) 45. 3 46.9 (496) 54. 9 42.3 (171) 37.2 Subadult females 52.4 (666) 53 .8 50.8 (846) 54. 1 54.2 (318) 73. 8 46.8 (542) 47.3 Subadult Males 60.5 (243) 51.9 51.7 (363) 68. 6 53.1 (716) 61. 0 32.5 (335) 35.2 A l l Bears 52.9 (1494) 49.4 48.5 (3819) 56. 0 52.1 (2074) 63. 1 40.8 (1603) 43.2 Some bears appear i n more than 1 p o p u l a t i o n component due t o changes i n age c l a s s and r e p r o d u c t i v e s t a t u s over the sample years. COYS = cubs-of-the-year. 59 Annual and Seasonal Trends On an annual b a s i s , sex-age c l a s s e s d i d not d i f f e r w i t h r e s p e c t t o median a c t i v e ( F i g . 9a), or median i n a c t i v e ( F i g . 9b) bout d u r a t i o n s as i n d i c a t e d by o v e r l a p p i n g notches on b o x p l o t s . For a l l bears p o o l e d by season, median a c t i v e bout d u r a t i o n s showed a t r e n d ( F i g . 10a) of d e c l i n i n g from s p r i n g through t o the b e r r y season and i n c r e a s i n g i n f a l l , w i t h median d u r a t i o n s i n the b e r r y season s i g n i f i c a n t l y l e s s than i n s p r i n g . I n a c t i v e bout d u r a t i o n s d i s p l a y e d s e v e r a l s i g n i f i c a n t changes ( F i g . 10b) s e a s o n a l l y , although s i g n i f i c a n c e may not be s t a b l e t o adjustments o f p a i r w i s e a l p h a l e v e l s f o r m u l t i p l e comparisons. R e g a r d l e s s , median d u r a t i o n s o f i n a c t i v e bouts showed an o p p o s i t e t r e n d t o a c t i v e bouts; i n c r e a s i n g from s p r i n g through t o the b e r r y season and d e c l i n i n g i n f a l l . A n a l y s e s W i t h i n Seasons With the e x c e p t i o n o f a c t i v e bouts i n f a l l , K r u s k a l - W a l l i s t e s t s of both a c t i v e and i n a c t i v e bout l e n g t h s were s i g n i f i c a n t (P < 0.05) i n each season, i n d i c a t i n g t h a t a t l e a s t one i n d i v i d u a l d i f f e r e d from the o t h e r s . C o n t r a s t s were generated f o r each K r u s k a l - W a l l i s t e s t (Tables 6 and 7) i n c l u d i n g f a l l a c t i v e bouts ( f o r the purpose o f d e t e c t i n g c o n s i s t e n t t r e n d s a c r o s s seasons). Many more s i g n i f i c a n t d i f f e r e n c e s were found among c o n t r a s t s t e s t i n g i n a c t i v e bouts than among a c t i v e bouts. CO CO < scf- a •a III a < i x iu CO AC?- 10 20 30 40 50 60 ACTIVE BOUT DURATION (min) CO CO < LU a < i x LU CO b s 9 - A 9 - SCT- •a ACf- —I 1 1 1 1 1 10 20 30 40 50 60 INACTIVE BOUT DURATION (min) F i g u r e 9. Notched box p l o t s o f complete a) a c t i v e , and b) i n a c t i v e , bout d u r a t i o n s pooled across seasons, f o r subadult females, a d u l t females, subadult males, and a d u l t males. Outside v a l u e s were omitted t o emphasize notches about the medians. For any 2 boxes with notches about the medians t h a t do not overlap, the 2 medians 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 approximately a 95% confidence l e v e l . I FA z B S O CO 3 ES CO {I SP 0 10 20 30 40 50 60 ACTIVE BOUT DURATION (min) z o CO < LU CO FA - BS ES b SP •{I 0 10 20 30 40 INACTIVE BOUT DURATION (min) i 1 — 50 60 F i g u r e 10. Notched box p l o t s of complete a) a c t i v e , and b) i n a c t i v e , bout d u r a t i o n s pooled across sex-age c l a s s e s , f o r s p r i n g (SP), e a r l y summer (ES), b e r r y season (BS), and f a l l (FA). Outside v a l u e s were omitted t o emphasize notches about the medians. For any 2 boxes wi t h notches about the medians t h a t do not overlap, the 2 medians 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 approximately a 95% confidence l e v e l . T a b l e 6. Te s t s of nonparametric m u l t i p l e c o n t r a s t s f o r d u r a t i o n s of complete i n a c t i v e bouts w i t h i n seasons. Values are t e s t s t a t i s t i c s (value of the c o n t r a s t d i v i d e d by i t s standard e r r o r ) . C o n t r a s t S p r i n g E a r l y Summer Berry Season F a l l 1) a d u l t male - subadults a 3.12 -4.10 a 0.26 -1.58 2) a d u l t female - subadults a 3.25 -1.92 0.84 -0.31 3) a d u l t M - a d u l t F 1.10 -2.56 a -0.48 -1.32 4) subadult M - subadult F a -3.51 1.76 -0.81 -0.21 5) a d u l t F alone - a d u l t F & coys 0.76 0.59 — — 6) a d u l t F alone - a d u l t F & y r l s — 1.55 1.19 2 .10 7) a d u l t F & coys - a d u l t F & y r l s — 1.17 — — 8) a d u l t M - a d u l t female alone 0.86 a -2.77 -0.76 -1.92 denotes s i g n i f i c a n c e a t an experimentwise e r r o r r a t e = 0.10. Note: M = males, F = females, coys = cubs-of-the-year, y r l s = y e a r l i n g s . T a b l e 7. T e s t s of nonparametric m u l t i p l e c o n t r a s t s f o r d u r a t i o n s of complete a c t i v e bouts w i t h i n seasons. Values are t e s t s t a t i s t i c s (value of the c o n t r a s t d i v i d e d by i t s standard e r r o r ) . C o n t r a s t Spring E a r l y Summer Berry Season F a l l 1) a d u l t M - subadults -1.57 2.05 0.96 -1.00 2) a d u l t F - subadults 1.12 , a 3.05 -0.09 0.11 3) a d u l t M - a d u l t F -2.14 -0.67 0.76 -1.02 4) subadult M - subadult F a 2.41 -0.002 -0.76 -1.03 5) a d u l t F alone - a d u l t F & coys 0.41 -0.53 — 6) a d u l t F alone - a d u l t F & y r l s — -1.02 -0.02 -0.48 7) a d u l t F & coys - a d u l t F & y r l s — -0.72 — 8) a d u l t M - a d u l t F alone -2.17 -0.28 0.74 -0.87 a denotes s i g n i f i c a n c e a t an experimentwise e r r o r r a t e = 0.10. Note: M = males, F = females, coys = cubs-of-the-year, y r l s = y e a r l i n g s . 64 a) E f f e c t s o f Age Age e f f e c t s were examined by t e s t i n g p o o l e d a d u l t males and p o o l e d a d u l t females each a g a i n s t a l l s u b a d u l t s p o o l e d t o g e t h e r ( c o n t r a s t s 1 and 2 of Ta b l e s 6 and 7). In s p r i n g , i n a c t i v e bouts were s i g n i f i c a n t l y l o n g e r f o r both male and female a d u l t s than s u b a d u l t s , w h i l e a c t i v e bout l e n g t h s were not s i g n i f i c a n t l y d i f f e r e n t . In e a r l y summer, both male and female a d u l t s tended t o have s h o r t e r i n a c t i v e bouts than s u b a d u l t s but o n l y the c o n t r a s t t e s t i n g a d u l t males a g a i n s t s u b a d u l t s was s i g n i f i c a n t . A c t i v e bouts tended t o be lo n g e r f o r a d u l t s o f e i t h e r sex than f o r su b a d u l t s but o n l y the c o n t r a s t t e s t i n g a d u l t females a g a i n s t s u b a d u l t s was s i g n i f i c a n t . C o n t r a s t s t e s t i n g a d u l t s a g a i n s t s u b a d u l t s were not s i g n i f i c a n t f o r i n a c t i v e o r a c t i v e bouts i n the b e r r y season o r i n f a l l . b) E f f e c t s o f Sex The e f f e c t s o f sex were t e s t e d w i t h i n a d u l t and subadu l t age c l a s s e s ( c o n t r a s t s 3 and 4 o f T a b l e s 6 and 7 ) . A d u l t males and a d u l t females d i f f e r e d s i g n i f i c a n t l y o n l y i n t h e i r e a r l y summer i n a c t i v e bout l e n g t h s which were s h o r t e r f o r a d u l t males. W i t h i n s u b a d u l t s , males had s i g n i f i c a n t l y s h o r t e r i n a c t i v e bouts than females and s i g n i f i c a n t l y l o n g e r a c t i v e bouts i n s p r i n g . There were no o t h e r s i g n i f i c a n t d i f f e r e n c e s found. 65 c) E f f e c t s o f Reproductive S t a t u s Not a l l c o n t r a s t s i n v o l v i n g a d u l t females o f d i f f e r e n t r e p r o d u c t i v e s t a t u s c o u l d be t e s t e d i n each season ( c o n t r a s t s 5, 6, and 7 of T a b l e s 6 and 7 ) . C o n t r a s t s t e s t i n g d i f f e r e n c e s between a d u l t females o f d i f f e r i n g s t a t u s were never s i g n i f i c a n t . A g e n e r a l t r e n d , however, was f o r females without o f f s p r i n g t o have l o n g e r i n a c t i v e bouts and s h o r t e r a c t i v e bouts than females w i t h cubs or y e a r l i n g s . R e s u l t s f o r females without o f f s p r i n g t e s t e d a g a i n s t a d u l t males ( c o n t r a s t 8 of T a b l e s 6 and 7) p a r a l l e l e d r e s u l t s f o r a l l a d u l t females t e s t e d a g a i n s t a d u l t males. However, most data f o r a d u l t females were from those without o f f s p r i n g . DISCUSSION On an annual b a s i s , sex-age c l a s s e s d i d not d i f f e r s i g n i f i c a n t l y i n median d u r a t i o n s o f e i t h e r i n a c t i v e o r a c t i v e bouts. However, c o n t r a s t s t e s t i n g sex-age c l a s s e s w i t h i n seasons r e v e a l e d t h a t some s i g n i f i c a n t d i f f e r e n c e s d i d e x i s t i n s p r i n g and e a r l y summer. When viewed a n n u a l l y , some w i t h i n season d i f f e r e n c e s among sex-age c l a s s e s a p p a r e n t l y c a n c e l l e d each o t h e r out or e l s e were masked by data p o o l i n g . Seasonal a n a l y s e s i n d i c a t e d marked d i f f e r e n c e s i n i n a c t i v e bout d u r a t i o n s among seasons f o r a l l sex-age c l a s s e s p o o l e d . For a c t i v e bout d u r a t i o n s , o n l y s p r i n g and the b e r r y season were s i g n i f i c a n t l y d i f f e r e n t . The t r e n d 66 from s p r i n g through t o the b e r r y season f o r a c t i v e bout d u r a t i o n s t o decrease, was c o n t r a r y t o e x p e c t a t i o n s d e r i v e d from e s t i m a t e s o f p e r c e n t o f time a c t i v e f o r a l l a v a i l a b l e d a t a by season (Table 5 ) . An apparent b i a s f o r complete bouts t o s e r i o u s l y u n derrepresent a c t i v e bouts o f l o n g d u r a t i o n was most pronounced f o r the b e r r y season and f o r e a r l y summer as i n d i c a t e d by the magnitude o f t h e d i s c r e p a n c i e s between the v a l u e s o f %TA c a l c u l a t e d from a l l a v a i l a b l e data f o r a l l bears (63.1% and 56.0% f o r the b e r r y season and e a r l y summer, r e s p e c t i v e l y ) and from complete bouts (52.1% and 48.5% f o r the b e r r y season and e a r l y summer, r e s p e c t i v e l y ) . These d i s c r e p a n c i e s p a r a l l e l e d t r e n d s from s p r i n g through t o the b e r r y season f o r an i n c r e a s e i n %TA (Table 5) and a g r e a t e r percentage o f t o t a l a c t i v e time spent i n bouts > 30 min d u r a t i o n . T h i s was c a l c u l a t e d from a l l a v a i l a b l e data and showed the p e r c e n t of t o t a l a c t i v e time i n bouts > 30 min was 68.9% i n s p r i n g , 78.9% i n e a r l y summer, 89.3% i n the b e r r y season, and 67.6% i n f a l l . The t r e n d f o r median a c t i v e bout d u r a t i o n s t o decrease from s p r i n g through t o the b e r r y season appeared t o be a consequence o f a b i a s a g a i n s t l o n g a c t i v e bouts due t o p e r i o d i c s i g n a l l o s s . T h i s r e s u l t e d from frequency d r i f t o r bears moving behind o b s t a c l e s and caused many l o n g a c t i v e bouts t o be c l a s s i f i e d as incomplete. In an o b s e r v a t i o n a l study o f a g r i z z l y f a m i l y i n n o r t h e r n A l a s k a , Gebhard (1982) noted t h a t g r i z z l i e s d i s p l a y e d l o n g e r a c t i v e and i n a c t i v e bouts i n J u l y and August than i n the p r e c e d i n g months. From 67 September t o denning he observed l o n g a c t i v e bouts i n t e r s p e r s e d w i t h s h o r t i n a c t i v e bouts, however, o b s e r v a t i o n s were hampered by i n c r e a s i n g darkness. While seasons d e f i n e s h i f t s i n f o r a g i n g a c t i v i t i e s by bears, s i g n i f i c a n t v a r i a t i o n i n food types w i t h i n seasons may s t i l l e x i s t among years o r among i n d i v i d u a l s . H e c h t e l ' s (1985) d a t a i n d i c a t e d t h a t the q u a n t i t i e s o f v a r i o u s s e a s o n a l food types u t i l i z e d by g r i z z l y bears i n a r c t i c A l a s k a v a r i e d among y e a r s . However, annual v a r i a t i o n cannot be s e p a r a t e d from i n d i v i d u a l v a r i a t i o n . M c L e l l a n (1989) found s i g n i f i c a n t w i t h i n - s e a s o n d i f f e r e n c e s i n the amount o f use d i f f e r e n t h a b i t a t s r e c e i v e d by sex, age and r e p r o d u c t i v e c l a s s e s o f g r i z z l y bears i n the F l a t h e a d . I n d i r e c t l y , these d i f f e r e n c e s i n h a b i t a t use suggest d i f f e r e n c e s i n food types and (or) abundance. D i f f e r e n c e s i n food types have been shown t o a f f e c t bout l e n g t h s . S c h l e y e r (1983) noted t h a t g r i z z l i e s f e e d i n g on c a r c a s s e s were s i g n i f i c a n t l y l e s s a c t i v e and e x h i b i t e d more s p o r a d i c a c t i v i t y p a t t e r n s than bears u t i l i z i n g o t h e r foods. While d i f f e r e n c e s were i n s i g n i f i c a n t , P h i l l i p s (1987) a l s o found g r i z z l i e s f e e d i n g on c a r c a s s e s t o have l o n g e r and more fre q u e n t r e s t p e r i o d s ( i n d i c a t i n g s h o r t e r i n t e r v e n i n g a c t i v e p e r i o d s ) than o t h e r b e a r s . The a v a i l a b i l i t y o f c a r r i o n i s se a s o n a l and g r e a t e s t i n the s p r i n g due t o w i n t e r k i l l o f ungulates, and a g a i n i n the f a l l due t o gut p i l e s and c r i p p l e d animals from h u n t i n g . 68 Simple c o n c l u s i o n s c o n c e r n i n g w i t h i n - s e a s o n sex and age e f f e c t s on a c t i v e and i n a c t i v e bout d u r a t i o n s are e l u s i v e f o r a t l e a s t 2 reasons. F i r s t , e f f e c t s t e s t e d i n s e v e r a l c o n t r a s t s were p r i m a r i l y or w h o l l y composed o f data from 1 i n d i v i d u a l (e.g., almost a l l data on s u b a d u l t males i n s p r i n g was from 1 b e a r ) . Consequently, i n d i v i d u a l v a r i a t i o n confounds some i n t e r p r e t a t i o n s . Second, complete a c t i v e bouts a r e b i a s e d , although the i n f l u e n c e of t h i s b i a s on the a n a l y s e s w i t h i n seasons i s d i f f i c u l t t o a s s e s s . A v a i l a b l e evidence suggests t h a t f o r s p r i n g and e a r l y summer, the e f f e c t s o f age and sex on a c t i v e and i n a c t i v e bout l e n g t h s are confounded. S i g n i f i c a n t d i f f e r e n c e s i n i n a c t i v e bout d u r a t i o n s between sex-age c l a s s e s i n s p r i n g are d i f f i c u l t t o e x p l a i n simply i n terms of i n t e r a c t i o n s between food types and body s i z e r e l a t i o n s . S i g n i f i c a n t l y l o n g e r i n a c t i v e bouts by a d u l t b ears may i n d i c a t e t h a t r e l a t i o n s h i p s between gut c a p a c i t y and m e t a b o l i c requirements r e s u l t i n s u b a d u l t s f o r a g i n g more f r e q u e n t l y . S i z e r e l a t e d d i f f e r e n c e s i n a ccess t o c a r r i o n may a l s o account f o r the l o n g e r i n a c t i v e bouts by a d u l t s . However, s i m i l a r d i f f e r e n c e s d i d not occur i n the f a l l i n s p i t e of the 2 seasons b e i n g s i m i l a r i n terms o f primary f o r a g e items (Hedvsarum sulphuresence r o o t s and c a r r i o n ; M c L e l l a n 1989). S i g n i f i c a n t d i f f e r e n c e s i n s p r i n g bout l e n g t h s between suba d u l t males and s u b a d u l t females may r e f l e c t sex r e l a t e d s i z e d i f f e r e n c e s between males and females. Subadults males 69 l i k e l y do not have the same o p t i o n s a v a i l a b l e f o r r e d u c i n g f o r a g i n g times as do a d u l t males (e.g., e x p r o p r i a t i n g p r o f i t a b l e f o r a g i n g s i t e s ) . A d d i t i o n a l l y , a f t e r l e a v i n g t h e i r dens i n the s p r i n g , g r i z z l y bears undergo a 2 - 3 week p e r i o d o f hypophagia (Nelson e t a l . 1983) b e f o r e resuming normal i n g e s t i o n r a t e s . Some d i f f e r e n c e s i n the s p r i n g may be due t o sampling bears i n d i f f e r e n t p h y s i o l o g i c a l s t a t e s . D i f f e r e n c e s between a d u l t s and su b a d u l t s tended t o r e v e r s e themselves i n e a r l y summer as compared t o s p r i n g . Both reduced c a r r i o n a v a i l a b i l i t y o r the i n f l u e n c e o f mating a c t i v i t y c o u l d be invoked as a p o t e n t i a l e x p l a n a t i o n s . Mating a c t i v i t y o c c u r s almost w h o l l y w i t h i n the e a r l y summer season and i n v o l v e s predominantly a d u l t s . Some o b s e r v a t i o n a l accounts o f c o u r t i n g bears ( P h i l l i p s 1987; Stelmock and Dean 1986; H e c h t e l 1985) i n d i c a t e t h a t both t o t a l time a c t i v e and the d i s t r i b u t i o n o f time i n t o a c t i v i t y bouts are m o d i f i e d d u r i n g c o u r t s h i p . S i g n i f i c a n t l y s h o r t e r i n a c t i v e bouts of a d u l t males compared t o a d u l t females may r e f l e c t i n c r e a s e d movements by males as they s e a r c h f o r r e p r o d u c t i v e l y a v a i l a b l e females. A f a i l u r e f o r i n c r e a s e d movements by a d u l t males t o be apparent as s i g n i f i c a n t l y l o n g e r a c t i v e bouts, c o u l d be due t o t h e i r moving out of range o f the r e c o r d i n g u n i t . The b e r r y season r e p r e s e n t s the p e r i o d w i t h the l e a s t v a r i a n c e i n primary food types consumed and w i t h the most r e s t r i c t e d movements by bears. A l a c k o f s i g n i f i c a n t d i f f e r e n c e s between sex-age c l a s s e s o f bears i n t h i s season 70 may be due t o the r e l a t i o n s h i p between r a t e s o f i n g e s t i o n and e x c r e t i o n . While i n g e s t i o n o f b e r r i e s i s a slow p r o c e s s , t r a n s i t times through the gut are s h o r t w i t h many b e r r i e s showing l i t t l e i n d i c a t i o n o f having been d i g e s t e d . C e s s a t i o n o f f o r a g i n g bouts may not be due t o gut f i l l . The hyperphagic b e h a v i o r o f bears i n the b e r r y season and the marked weight g a i n s achieved, a l s o i n d i c a t e t h a t bears are not merely responding t o immediate m e t a b o l i c requirements. Bout l e n g t h s are t h e r e f o r e uncoupled from p r e d i c t i o n s based on such requirements and from simple r u l e s such as 'feed u n t i l f u l l ' ( B unnell and G i l l i n g h a m 1985). 71 LITERATURE CITED B u n n e l l , F. L., and M. P. G i l l i n g h a m . 1985. F o r a g i n g b e h a v i o r : dynamics of d i n i n g out. In B i o e n e r g e t i c s of w i l d h e r b i v o r e s . E d i t e d by R. j . Hudson and R. G. White. CRC Pr e s s , Boca Raton, F l o r i d a , pp. 53-79. B u n n e l l , F. L., and T. Hamilton. 1983. Forage d i g e s t i b i l i t y and f i t n e s s i n g r i z z l y b ears. I n t . Conf. Bear Res. and Manage. 5:179-185. B u n n e l l F. L., and A. S. Harestad. 1989. A c t i v i t y budgets and body weight i n mammals: how sloppy can mammals be? Cu r r . Mammal. 2:245-305. Conover, W. J . 1971. P r a c t i c a l nonparametric s t a t i s t i c s . John W i l e y and Sons, Inc., New York, New York. 462 pp. Demment, M. W. 1983. Feeding ecology and t h e e v o l u t i o n o f body s i z e o f baboons. A f r . J . E c o l . 21:219-233. Dunn, O. J . 1964. M u l t i p l e c o n t r a s t s u s i n g rank sums. Technometrics 6:241-252. Egbert, A. L., and A. W. Stokes. 1976. The s o c i a l b e h a v i o r of brown bears on an A l a s k a n salmon stream. I n t . Conf. Bear Res. and Manage. 3:41-56. Feldman, H. A., and T. A. McMahon. 1983. The 3/4 mass exponent f o r metabolism i s not a s t a t i s t i c a l a r t i f a c t . Resp. P h y s i o l . 52:149-163. Gebhard, J . G. 1982. Annual a c t i v i t i e s and b e h a v i o r o f a g r i z z l y bear (Ursus a r c t o s ) f a m i l y i n n o r t h e r n A l a s k a . M.Sc. T h e s i s . Univ. A l a s k a , F a i r b a n k s , A l a s k a . 218 pp. Gibbons, J . D. 1985. Nonparametric methods f o r q u a n t i t a t i v e a n a l y s i s . 2nd edn. American S c i e n c e s P r e s s , Inc., Columbus, Ohio. 481 pp. H e c h t e l , J . L. 1985. A c t i v i t y and food h a b i t s o f b a r r e n - ground g r i z z l y bears i n A r c t i c A l a s k a . M.Sc. T h e s i s . Univ. Montana, M i s s o u l a , Montana. 74 pp. Herbers, J . M. 1981. Time r e s o u r c e s and l a z i n e s s i n animals O e c o l o g i a . 49:252-262. Heusner, A. A. 1982. Energy metabolism and body s i z e . I . I s the 0.75 mass exponent of K l e i b e r ' s e q u a t i o n a s t a t i s t i c a l a r t i f a c t ? Resp. P h y s i o l . 48:1-12. K l e i b e r , M. 1975. The f i r e o f l i f e : an i n t r o d u c t i o n t o animal e n e r g e t i c s . K r i e g e r Pub. Co., Huntington, New York. 453 pp. L l o y d , L. E., B. E. McDonald, and E. W. Crampton. 1978. Fundamentals of n u t r i t i o n . 2nd edn. W. H. Freeman and Company, San F r a n c i s c o , C a l i f o r n i a . 466 pp. M c L e l l a n , B. N. 1989. E f f e c t s of r e s o u r c e e x t r a c t i o n i n d u s t r i e s on b e h a v i o r and p o p u l a t i o n dynamics of g r i z z l y bears i n the F l a t h e a d drainage, B r i t i s h Columbia and Montana. Ph.D. T h e s i s , Univ. o f B r i t i s h Columbia, Vancouver, B r i t i s h Columbia. 115 pp. M c G i l l , R., J . W. Tukey, and W. A. Larsen. 1978. V a r i a t i o n s o f box p l o t s . The American S t a t i s t i c i a n 32:12-16. Nelson, R. A., G. E. F o l k , E. W. P f e i f f e r , J . J . Craighead, C. J . J o n k e l , and D. L. S t e i g e r . 1983. Behavior, b i o c h e m i s t r y , and h i b e r n a t i o n i n b l a c k , g r i z z l y , and p o l a r b e a r s . I n t . Conf. Bear Res and Manage. 5:284-290 Pearson, A. M. 1975. The n o r t h e r n i n t e r i o r g r i z z l y bear (Ursus a r c t o s L ) . Can. W i l d l . Serv. Rep. Ser. No. 34. 86 pp. P h i l l i p s , M. K. 1987. Behavior and h a b i t a t use o f g r i z z l y bears i n n o r t h e a s t e r n A l a s k a . I n t . Conf. Bear Res. and Manage. 7:159-167. 73 S c h l e y e r , B. 0. 1983. A c t i v i t y p a t t e r n s of g r i z z l y bears i n the Yellowstone ecosystem and t h e i r r e p r o d u c t i v e b e h a v i o r , p r e d a t i o n and use o f c a r r i o n . M.Sc. T h e s i s , Mont. S t a t e Univ., Bozeman, Montana. 130 pp. So k a l , R. R., and F. J . R o h l f . 1981. Biometry. 2nd edn. W. H. Freeman and Company, New York, New York. 859 pp. Stelmock, J . J . , and F. C. Dean. 1986. Brown bear a c t i v i t y and h a b i t a t use, D e n a l i N a t i o n a l Park - 1980. I n t . Conf. Bear Res. and Manage. 6:155-168. Stonorov D., and A. W. Stokes. 1972. S o c i a l b e h a v i o r o f the A l a s k a brown bear. I n t . Conf. Bear Res. and Manage. 2:232-242. Velleman, P. F., and D. C. H o a g l i n . 1981. A p p l i c a t i o n s , b a s i c s , and computing of e x p l o r a t o r y data a n a l y s i s . Duxbury P r e s s , Boston, Massachusetts. 354 pp. W i l k i n s o n , L. 1989. S y s t a t : the system f o r s t a t i s t i c s . S y s t a t , Inc., Evanston, I l l i n o i s . 822 pp. W i l k i n s o n , L. 1988. Sygraph. S y s t a t , Inc., Evanston, I l l i n o i s . 980 pp. 74 CHAPTER 4: ACTIVITY BUDGETS AND PATTERNS INTRODUCTION Major r e d u c t i o n s i n the g r i z z l y b e a r s ' range over the l a s t 150 y e a r s , and the r e s t r i c t i o n of c u r r e n t p o p u l a t i o n s t o r e l a t i v e l y l a r g e w i l d e r n e s s areas, has i n d i c a t e d t h a t g r i z z l i e s may r e q u i r e s e c l u s i o n from humans i n o r d e r t o s u r v i v e (Knight 1980). However, most oc c u p i e d g r i z z l y h a b i t a t l i e s w i t h i n areas managed under i n t e g r a t e d l a n d management p h i l o s o p h i e s which pursue i n c r e a s e d development, o r e l s e w i t h i n parks t h a t are under i n c r e a s i n g r e c r e a t i o n a l use by humans. Recent s t u d i e s i n the F l a t h e a d R i v e r d r a i n a g e o f s o u t h e a s t e r n B r i t i s h Columbia and a d j a c e n t areas of Montana have documented o v e r t b e h a v i o r a l responses by g r i z z l i e s t o human a c t i v i t i e s (McLellan and S h a c k l e t o n 1989a, 1989b), and h a b i t a t l o s s due t o avoidance of h a b i t a t s c l o s e t o roads b u i l t t o support l o g g i n g and petroleum e x p l o r a t i o n (McLellan and S h a c k l e t o n 1988). However, n e g a t i v e demographic responses of the g r i z z l y p o p u l a t i o n t o t h e s e human i n t r u s i o n s have not been demonstrated (McLellan 1989; M c L e l l a n and S h a c k l e t o n 1988). The i m p l i c a t i o n t h e r e f o r e , i s t h a t g r i z z l i e s can c o e x i s t w i t h some l e v e l of human a c t i v i t y i f the l a t t e r i s p r o p e r l y c o n t r o l l e d . T h i s i s supported by the f a c t t h a t a l l known g r i z z l y m o r t a l i t i e s were due t o human p r e d a t i o n (McLellan and S h a c k l e t o n 1988). A prima f a c i e aphorism t h a t g r i z z l i e s can not adapt t o humans i s s l o w l y b e i n g r e p l a c e d by the r e a l i z a t i o n t h a t the 75 problem w i t h a d a p t a b i l i t y p r i m a r i l y l i e s w i t h people, not w i t h b e a r s . In areas o f h i g h human use, mammals a v o i d harassment from humans by s w i t c h i n g t h e i r a c t i v i t y t o l o c a t i o n s and times when human a c t i v i t y i s minimal ( G e i s t 1971). S p a t i a l avoidance o f humans by g r i z z l y bears has been r e p o r t e d f o r p o p u l a t i o n s o t h e r than the F l a t h e a d (e.g., A r c h i b a l d e t a l . 1987; Mattson e t a l . 1987; Harding and Nagy 1980). However, Servheen (1981) noted t h a t darkness may p r o v i d e cover f o r bears and M c L e l l a n and Shac k l e t o n (1988) found t h a t bears d i d use h a b i t a t s near roads s i g n i f i c a n t l y more o f t e n d u r i n g the n i g h t than d u r i n g the day. S e v e r a l r e c e n t s t u d i e s o f a c t i v i t y budgets and p a t t e r n s o f g r i z z l y p o p u l a t i o n s i n North America and Europe have i n d i c a t e d t h a t i n c r e a s e d n o c t u r n a l a c t i v i t y by bears may be an a d a p t a t i o n t o a v o i d human a c t i v i t y (Clevenger e t a l . 1990; Aune and Kasworm 1989; B j a r v a l l and Sandegren 1987; Roth and Huber 1986; Roth 1983) and may reduce the exte n t o f h a b i t a t l o s s due t o avoidance e x p e r i e n c e d by p o p u l a t i o n s c o e x i s t i n g w i t h humans (McL e l l a n and Sh a c k l e t o n 1988). A c t i v i t y budget data have been f r e q u e n t l y suggested as a means o f s t u d y i n g r e l a t i o n s h i p s between the environment ( i n c l u d i n g human induced d i s t u r b a n c e s ) and p o p u l a t i o n s , c l a s s e s o f i n d i v i d u a l s (e.g., sex, age, r e p r o d u c t i v e o r s o c i a l c l a s s e s ) , and i n d i v i d u a l s themselves (Roth 1983; Jacobsen and Wiggins 1982; Boy and Duncan 1979; Eberhardt 1977). Roth (1983) suggested t h a t q u a n t i f y i n g a c t i v i t y 76 p a t t e r n s o f a s p e c i e s under v a r y i n g environmental c o n d i t i o n s ( i n c l u d i n g human i n t r u s i o n ) may permit some a c t i v i t y parameters t o be used as i n d i c a t o r s o f s t r e s s p l a c e d on a p a r t i c u l a r p o p u l a t i o n by i t s environment. However, t o be of use, b a s e l i n e i n f o r m a t i o n on a c t i v i t y parameters must account f o r v a r i a t i o n due t o f a c t o r s such as sex, age, and r e p r o d u c t i v e s t a t u s , and be indexed t o h a b i t a t p r o d u c t i v i t y , t o t he i n t e n s i t y and type o f human i n t r u s i o n s , and t o the p o p u l a t i o n ' s demographic s t a t u s . F r e q u e n t l y , such v i t a l i n f o r m a t i o n i s m i s s i n g o r i s known o n l y q u a l i t a t i v e l y . P r e v i o u s s t u d i e s o f g r i z z l y bear a c t i v i t y p a t t e r n s and budgets have f r e q u e n t l y been hampered by s m a l l numbers of i n d i v i d u a l b e a r s , and r e l a t i v e l y s m a l l sums o f t o t a l time monitored. T h i s has g e n e r a l l y prevented e x p l o r a t i o n o f sex and age e f f e c t s , and d e t r a c t e d from examinations o f seasonal e f f e c t s due t o confounding. D e t a i l e d , q u a n t i t a t i v e i n f o r m a t i o n on how much time bears a l l o c a t e t o a c t i v i t y (as opposed t o i n a c t i v i t y ) may r e v e a l c o n s t r a i n t s p l a c e d on them by t h e i r environment, and a l l o w i d e n t i f i c a t i o n o f c r i t i c a l p e r i o d s o r e s s e n t i a l environmental f a c t o r s i n t h e i r annual c y c l e . Comparisons among d i f f e r e n t sex and age c l a s s e s can r e v e a l c r i t i c a l p e r i o d s i n the l i f e c y c l e o f the s p e c i e s . T h i s c h a p t e r addresses time a l l o c a t i o n i n f r e e - r a n g i n g g r i z z l y bears w i t h r e s p e c t t o t o t a l time spent i n the a c t i v e s t a t e , and the d i s t r i b u t i o n o f a c t i v e time over the 24-hour c y c l e . S p e c i f i c o b j e c t i v e s were t o : 1) compare a c t i v i t y budgets among sex and age c l a s s e s o f g r i z z l y bears both 77 w i t h i n and among seasons; 2) compare d i s t r i b u t i o n s of a c t i v i t y over t h e d i e l c y c l e among sex and age c l a s s e s o f g r i z z l y b e ars both w i t h i n and among seasons; and 3) t o q u a l i t a t i v e l y compare d i e l a c t i v i t y p a t t e r n s and a c t i v i t y budgets f o r the F l a t h e a d g r i z z l y p o p u l a t i o n w i t h o t h e r documented p o p u l a t i o n s . METHODS F i e l d procedures were as d e s c r i b e d i n Chapter 1. Chart a n a l y s i s f o l l o w e d the r u l e s p r e s e n t e d i n Chapter 2. I n d i v i d u a l r e c o r d i n g s e s s i o n s on bears v a r i e d g r e a t l y i n l e n g t h . I d e a l l y , s t a t i s t i c a l comparisons o f a c t i v i t y budgets and p a t t e r n s over the d i e l c y c l e s hould be based on complete 24-hour samples o f a c t i v i t y so as t o encompass d a y l i g h t and darkness and s t a n d a r d i z e the d u r a t i o n of time t h a t a sample encompasses. However, complete 24-hour samples were l i m i t e d i n number (44 samples, o r o n l y 22% o f the data base) and were p o o r l y d i s t r i b u t e d a c r o s s i n d i v i d u a l s and seasons. Time-sampling the c h a r t s c o u l d have r e s u l t e d i n s e v e r a l thousand " o b s e r v a t i o n s " . While p r e v i o u s s t u d i e s u t i l i z i n g time-sampling o f r a d i o c o l l a r s i g n a l s f r e q u e n t l y have used i n d i v i d u a l time-samples as independent o b s e r v a t i o n s i n a n a l y t i c a l treatments o f the data, t h e assumption o f independence i s not l i k e l y warranted. As a compromise between these 2 extremes i n the concept o f an o b s e r v a t i o n , the 24-hour c y c l e was s t r a t i f i e d i n t o 4 m u t u a l l y e x c l u s i v e time p e r i o d s . However, t h i s d i d 78 not exclude some i n t e r d e p e n d e n c i e s e x i s t i n g w i t h i n t h e data. F o r each time p e r i o d sampled f o r each bear, p e r c e n t o f time a c t i v e (%TA) was determined as t o t a l time i n the a c t i v e bout c a t e g o r y d i v i d e d by the sum of t o t a l time i n both a c t i v e and i n a c t i v e c a t e g o r i e s . Many time p e r i o d s were not sampled completely depending on when the r e c o r d i n g was i n i t i a t e d o r i f the s i g n a l was l o s t . Any time p e r i o d f o r which < 75% of the p e r i o d ' s d u r a t i o n was reco r d e d was r e j e c t e d from a n a l y s e s . Comparisons of A c t i v i t y P a t t e r n s A c t i v i t y p a t t e r n s were examined w i t h r e s p e c t t o the d a i l y c y c l e o f d a y l i g h t and darkness. S t r a t i f i c a t i o n o f the 24-hour c y c l e i n t o 4 time p e r i o d s ( h e r e a f t e r r e f e r r e d t o as " d i e l p e r i o d s " ) was based on s u n r i s e and sunset. Morning and evening d i e l p e r i o d s were each 3 h l o n g and extended from 1.5 h b e f o r e , t o 1.5 h a f t e r , s u n r i s e and sunset, r e s p e c t i v e l y . D i u r n a l and n o c t u r n a l d i e l p e r i o d s v a r i e d i n l e n g t h throughout the yea r . Comparisons o f a c t i v i t y p a t t e r n s (percent o f time a c t i v e i n each d i e l p e r i o d ) among sex-age c l a s s e s and seasons were conducted w i t h a mixed model n e s t e d - f a c t o r i a l a n a l y s e s o f v a r i a n c e (Hicks 1982, p. 233). F o r both s p r i n g and f a l l , t h e r e were i n s u f f i c i e n t d a ta t o t e s t a d u l t males. The a n a l y s i s t e s t e d t h e remaining 3 sex-age c l a s s e s ( a d u l t females, s u b a d u l t females, s u b a d u l t males) as treatments o f a main e f f e c t which was f a c t o r i a l w i t h d i e l p e r i o d s and seasons. I n d i v i d u a l bears (3 a d u l t 79 females, 3 suba d u l t females, 2 suba d u l t males) were nested w i t h i n t h e i r r e s p e c t i v e sex-age c l a s s . For e a r l y summer and the b e r r y season, d a t a were s u f f i c i e n t t o t e s t a l l 4 sex-age c l a s s e s . A mixed model n e s t e d - f a c t o r i a l a n a l y s i s o f v a r i a n c e t e s t e d seasons, sex, age, and d i e l p e r i o d as c r o s s e d f a c t o r s w i t h i n d i v i d u a l bears (2 a d u l t males, 3 a d u l t females, 3 su b a d u l t males, 2 sub a d u l t f e m a l e s ) , nested w i t h i n t h e i r r e s p e c t i v e sex-age c l a s s . Comparisons of A c t i v i t y Budgets A c t i v i t y budgets c o u l d not be asses s e d from the above a n a l y s e s s i n c e the 4 time p e r i o d s used were not o f equal l e n g t h and mean %TA f o r main e f f e c t s d i d not r e f l e c t a c t u a l d u r a t i o n o f time a c t i v e . Conversion o f %TA f o r each d i e l p e r i o d o b s e r v a t i o n t o a c t u a l time a c t i v e , o r w e i g h t i n g by the p r o p o r t i o n o f a 24-hour c y c l e t h a t the p e r i o d r e p r e s e n t e d , would have meant t h a t d i f f e r e n t p e r i o d s had d i f f e r e n t p o t e n t i a l ranges over which the v a l u e s o f o b s e r v a t i o n s c o u l d v a r y . As an a l t e r n a t i v e , 4 new time p e r i o d s ("quarter d a y s " ) , each 6 h i n d u r a t i o n (0500 - 1100, 1100 - 1700, 1700 - 2300, 2300 - 0500; MDT) were d e f i n e d . A n a l y s e s were conducted as d e s c r i b e d above w i t h d i e l p e r i o d s r e p l a c e d by a q u a r t e r day e f f e c t . A l l a n a l y s e s o f a c t i v i t y budgets and p a t t e r n s had d i s p r o p o r t i o n a t e numbers o f i n d i v i d u a l bears w i t h i n sex-age 80 c l a s s e s and unequal numbers o f o b s e r v a t i o n s on i n d i v i d u a l s . A n a l y s e s comparing a c t i v i t y p a t t e r n s and budgets among a l l 4 seasons a l s o s u f f e r e d from m i s s i n g c e l l s (notably, s u b a d u l t males i n s p r i n g were r e p r e s e n t e d by o n l y 1 i n d i v i d u a l ) . Under the s e c o n d i t i o n s the Type 1 e r r o r r a t e may be d i f f e r e n t than t h a t intended, and can be e i t h e r more or l e s s c o n s e r v a t i v e . Some e f f e c t s w i t h i n a n a l y s e s a l s o f a i l e d t o meet t h e assumption o f homogeneity o f v a r i a n c e . R e s u l t s , t h e r e f o r e , must be i n t e r p r e t e d w i t h c a u t i o n . A n a l y s e s were performed on UBC GENLIN ( G r i e g and B j e r r i n g 1978) w i t h a r c s i n e square r o o t transformed v a l u e s (Sokal and R o h l f 1981, p. 427) . D i f f e r e n c e s between means were i n v e s t i g a t e d w i t h Newman-Keuls range t e s t s (Hicks 1982, p. 51). The alpha l e v e l f o r a l l t e s t s was 0.05. A l l r e p o r t e d a c t i v i t y l e v e l s a r e back-transformed p r e d i c t e d means o f %TA ± SEM r a t h e r than observed means. Due t o t h e l a r g e number and com p l e x i t y o f some i n t e r a c t i o n s , i n t e r p r e t a t i o n s o f i n t e r a c t i o n s were made w i t h r e s p e c t t o t r e n d s o n l y . RESULTS A c t i v i t y P a t t e r n s F o r a c t i v i t y p a t t e r n s , the e f f e c t s o f i n t e r e s t i n the an a l y s e s o f v a r i a n c e are the d i e l p e r i o d main e f f e c t s and i n t e r a c t i o n s i n c l u d i n g d i e l p e r i o d . Comparisons over a l l 4 seasons (Table 8) i n d i c a t e d s i g n i f i c a n t d i f f e r e n c e s i n bear a c t i v i t y l e v e l s among d i e l p e r i o d s . However, f i r s t o r d e r i n t e r a c t i o n s i n v o l v i n g d i e l p e r i o d s were s i g n i f i c a n t f o r 81 T a b l e 8. Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e o f a c t i v i t y p a t t e r n s f o r g r i z z l y bears over seasons. SA C l a s s r e p r e s e n t s those sex-age c l a s s e s (subadult males, subadult females, a d u l t females) f o r which t h e r e were s u f f i c i e n t d ata t o t e s t . Source o f v a r i a t i o n d . f . M.S. F Season 3 1. 228 12. 018 SA C l a s s 2 0. 021 0. 024 D i e l P e r i o d 3 10. 000 57. 228 Bear(SA C l a s s ) 5 0. 860 11. 474 Season x SA C l a s s 6 0. 250 2. 451 Season x D i e l P e r i o d 9 0. 248 3. 496 SA C l a s s x D i e l P e r i o d 6 0. 172 0. 982 Season x Bear(SA C l a s s ) 13 0. 102 1. 363 Season x SA C l a s s x D i e l P e r i o d 18 0. 087 1. 221 D i e l P e r i o d x Bear(SA C l a s s ) 15 0. 175 2. 332 Season x D i e l P e r i o d x Bear(SA C l a s s ) 34 0. 071 0. 947 Prob. <0.001* 0.976 <0.001c <0.001€ 0.083 £ 0.004C 0.471 c 0.176C 0.299 0.004 0.556 R e s i d u a l T o t a l 309 423 0.075 a T e s t e d a g a i n s t Season x Bear(SA C l a s s ) T e s t e d a g a i n s t Bear(SA C l a s s ) ^ T e s t e d a g a i n s t D i e l P e r i o d x Bear(SA C l a s s ) T e s t e d a g a i n s t Season x D i e l P e r i o d x Bear(SA C l a s s ) e T e s t e d a g a i n s t R e s i d u a l 82 both seasons and i n d i v i d u a l bears (Table 8 ) . Pooled over a l l o t h e r f a c t o r s , a c t i v i t y l e v e l s f o r the 4 d i e l p e r i o d s i n d i c a t e d low n o c t u r n a l a c t i v i t y (16.0 ± 2.8%), s i m i l a r l y h i g h a c t i v i t y l e v e l s f o r the morning and d i u r n a l p e r i o d s (68.7 ± 2.8% and 69.4 ± 3.1%, r e s p e c t i v e l y ) , and a peak i n a c t i v i t y i n t h e evening p e r i o d (80.3 ± 2.3%). R e g a r d l e s s o f season, the lowest a c t i v i t y l e v e l s were f o r bears i n n o c t u r n a l p e r i o d s ( F i g . 11). W i t h i n any season a c t i v i t y l e v e l s were the h i g h e s t i n the evening p e r i o d ( F i g . 11), however, among seasons t h i s was not t r u e . Large v a r i a t i o n i n a c t i v i t y l e v e l s was e v i d e n t among seasons i n the morning p e r i o d . W i t h i n any i n d i v i d u a l , n o c t u r n a l p e r i o d s p o o l e d over seasons were always the l e a s t a c t i v e . For 7 o f the 8 i n d i v i d u a l s , the n o c t u r n a l a c t i v i t y l e v e l s were t h e lowest v a l u e s o v e r a l l (range: 6.8 ± 9.2% t o 28.1 ± 12.3%). Four bears (1 suba d u l t female, 1 s u b a d u l t male, 2 a d u l t females) d i s p l a y e d a bimodal a c t i v i t y p a t t e r n w i t h a c t i v i t y peaks o c c u r r i n g i n the morning and evening p e r i o d s , the remaining 4 bears (1 a d u l t female, 2 s u b a d u l t females, 1 sub a d u l t male) e x h i b i t e d an i n c r e a s i n g a c t i v i t y l e v e l from t h e morning through t o t h e evening p e r i o d . Comparisons between e a r l y summer and the b e r r y season, w i t h sex and age f a c t o r i a l , a l s o r e s u l t e d i n s i g n i f i c a n t d i f f e r e n c e s among d i e l p e r i o d s (Table 9 ) . However, a f i r s t o r d e r i n t e r a c t i o n between d i e l p e r i o d and age, and a second o r d e r i n t e r a c t i o n i n v o l v i n g season, sex and d i e l p e r i o d were s i g n i f i c a n t (Table 9 ) . The p a t t e r n o f a c t i v i t y a c r o s s d i e l I morning diurnal evening noc turna l DIEL PERIOD F i g u r e 11. F i r s t o r d e r i n t e r a c t i o n between seasons and d i e l p e r i o d s from A n a l y s i s o f Variance o f g r i z z l y bear a c t i v i t y p a t t e r n s over seasons (Table 7 ) . P l o t t e d v a l u e s are p r e d i c t e d c e l l means. CO 84 T a b l e 9. Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e o f a c t i v i t y p a t t e r n s f o r sex-age c l a s s e s o f g r i z z l y b ears over e a r l y summer and the b e r r y season. Source o f v a r i a t i o n d . f . M.S. F Season 1 0. 908 2. 548 Sex 1 0. 082 0. 126 Age D i e l P e r i o d 1 0. ,130 0. 120 3 10. ,758 88. 970 Bear(Sex x Age) 6 0. ,654 8. 122 Season x Sex 1 0. ,394 1. 105 Season x Age 1 0. ,002 0. 005 Sex x Age 1 0. ,150 0. 229 Sex x D i e l P e r i o d 3 0. .342 2. 830 Age x D i e l P e r i o d 3 0. .645 5. 333 Season x Bear(Sex x Age) 6 0. .356 4. 429 Season x Sex x Age 1 0. .321 0. 900 Season x D i e l P e r i o d 3 0. .032 0. 478 Sex x Age x D i e l P e r i o d 3 0, .142 1. 176 Season x Sex x D i e l P e r i o d 3 0. .237 3. 503 Season x Age x D i e l P e r i o d 3 0, .021 0. 317 Season x Sex x Age x D i e l P e r i o d 3 0. .014 0. 205 D i e l P e r i o d x Bear(Sex x Age) 18 0, .121 1. 503 Season x D i e l P e r i o d x Bear(Sex x Age) 17 0. .068 0. 842 R e s i d u a l 313 0, .080 Prob. 0.162* 0.7357 0.671 <0.001 C <0.001 e 0.334 a ° ' 9 4 6 K 0.649 0.068 C 0.008 C <0.001 e 0.380* 0.702 0.347 C 0.038 d 0.813 d 0.891 d 0.087 6 0.643 6 T o t a l 391 * T e s t e d a g a i n s t Season x Bear(Sex x Age C l a s s ) T e s t e d a g a i n s t Bear(Sex x Age Cl a s s ) ^ T e s t e d a g a i n s t D i e l P e r i o d x Bear(Sex x Age C l a s s ) T e s t e d a g a i n s t Season x D i e l P e r i o d x Bear(Sex x Age) e T e s t e d a g a i n s t R e s i d u a l 85 p e r i o d s p o o l e d over a l l o t h e r f a c t o r s i n d i c a t e d a bimodal d i s t r i b u t i o n w i t h a c t i v i t y l e v e l s of 19 ± 2.9%, and 71.6 ± 3.5% i n the n o c t u r n a l and d i u r n a l p e r i o d s r e s p e c t i v e l y , w h i l e a c t i v i t y l e v e l s i n the morning and evening p e r i o d s were 80.0 ± 2.8% and 84.7 ± 2.6% r e s p e c t i v e l y . The age x d i e l p e r i o d i n t e r a c t i o n ( F i g . 12) i n d i c a t e d t h a t s u b a d u l t s were more a c t i v e i n a l l d i e l p e r i o d s except f o r the n o c t u r n a l p e r i o d when they were l e s s a c t i v e than a d u l t s . A d u l t s d i s p l a y e d a bimodal a c t i v i t y p a t t e r n a c r o s s d i e l p e r i o d s w h i l e s u b a d u l t s e x h i b i t e d l i t t l e d i f f e r e n c e i n a c t i v i t y between the morning and d i u r n a l p e r i o d s and an a c t i v i t y peak i n the evening p e r i o d . A c r o s s seasons, sex c l a s s e s showed l i t t l e d i f f e r e n c e i n a c t i v i t y i n t h e n o c t u r n a l p e r i o d ( F i g . 13a and b ) . R e s p e c t i v e l y , sex c l a s s e s tended t o have h i g h e r a c t i v i t y l e v e l s over t h e remaining d i e l p e r i o d s i n the b e r r y season than they d i d i n the e a r l y summer. In both seasons, females e x h i b i t e d a peak i n a c t i v i t y i n the evening p e r i o d , males tended t o be s l i g h t l y more a c t i v e i n the morning than i n the evening p e r i o d . In e a r l y summer, male and female a c t i v i t y l e v e l s c o n t r a s t e d s h a r p l y between morning and d i u r n a l p e r i o d s . A c t i v i t y Budgets Comparisons o f a c t i v i t y budgets over a l l 4 seasons (Table 10) i n d i c a t e d s i g n i f i c a n t d i f f e r e n c e s i n the main e f f e c t s o f seasons, q u a r t e r day p e r i o d s , and i n d i v i d u a l b e a r s . No d i f f e r e n c e s i n a c t i v i t y were apparent f o r t h e 100 Age Class subadults adults morning diurnal evening nocturnal DIEL PERIOD F i g u r e 12. F i r s t o r d e r i n t e r a c t i o n between age c l a s s e s and d i e l p e r i o d s from A n a l y s i s o f V a r i a n c e o f g r i z z l y bear a c t i v i t y p a t t e r n s f o r sex-age c l a s s e s over e a r l y summer and the b e r r y season (Table 8.) P l o t t e d v a l u e s a r e p r e d i c t e d c e l l means. F i g u r e 13. Second order i n t e r a c t i o n between seasons, sex c l a s s e s , and d i e l p e r i o d s from A n a l y s i s of Variance of g r i z z l y bear a c t i v i t y p a t t e r n s f o r sex-age c l a s s e s over e a r l y summer and the b e r r y season (Table 8) . Sex x d i e l p e r i o d i n t e r a c t i o n s are p l o t t e d f o r a) e a r l y summer, and b) the b e r r y season. P l o t t e d v a l u e s are p r e d i c t e d c e l l means. 88 T a b l e 10. Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e o f a c t i v i t y budgets f o r g r i z z l y b e ars over seasons. SA C l a s s r e p r e s e n t s those sex-age c l a s s e s (subadult males, sub a d u l t females, a d u l t females) f o r which t h e r e were s u f f i c i e n t data t o t e s t . Source o f v a r i a t i o n d . f . M.S. F Prob. Season 3 1. 021 20 .143 <0.001 a SA C l a s s 2 0. 008 0 .007 0.993 Quarte r Day 3 8. 460 43 .202 <0.001 C Bear(SA C l a s s ) 5 1. 131 16 .239 <o.ooi e Season x SA C l a s s 6 0. 127 2 .500 0.083 a Season x Quarter Day 9 0. 282 4 .306 <0.001 d SA C l a s s x Quarter Day 6 0. 159 0 .812 0.577 C Season x Bear(SA C l a s s ) 12 0. 051 0 .728 0.724 6 Season x SA C l a s s x J Quarter Day 18 0. 140 2 .137 0.027 Quarter Day x Bear(SA C l a s s ) 15 0. 196 2 .811 <0.001 e Season x Quarter Day x Bear(SA C l a s s ) 35 0. 065 0 .939 0.571 6 R e s i d u a l 316 0. 070 T o t a l 430 a T e s t e d a g a i n s t Season x Bear(SA C l a s s ) T e s t e d a g a i n s t Bear(SA C l a s s ) ^ T e s t e d a g a i n s t Quarter Day x Bear(SA C l a s s ) T e s t e d a g a i n s t Season x Quarter Day x Bear(SA C l a s s ) e T e s t e d a g a i n s t R e s i d u a l 89 sex-age c l a s s e f f e c t . However, a l l main e f f e c t s were i n v o l v e d i n s i g n i f i c a n t i n t e r a c t i o n s and c o u l d not be i n t e r p r e t e d r e l i a b l y . Seasonal a c t i v i t y l e v e l s were 41.0 ± 3.5% i n t h e s p r i n g , 58.7 ± 2.1% i n the e a r l y summer, 64.4 ± 2.5% i n t h e b e r r y season and 44.1 ± 3.2% i n t h e f a l l . A f i r s t o r d e r i n t e r a c t i o n between seasons and q u a r t e r day p e r i o d s , and a second o r d e r i n t e r a c t i o n between seasons, sex-age c l a s s e s and q u a r t e r day p e r i o d s were s i g n i f i c a n t (Table 10). In s p r i n g and f a l l , a c t i v i t y l e v e l s p o o l e d over sex-age c l a s s e s were g e n e r a l l y lower a c r o s s q u a r t e r day p e r i o d s than i n e a r l y summer and the b e r r y season ( F i g . 14). The most n o t a b l e e x c e p t i o n was between 2300 - 0500 hours d u r i n g which bears i n the f a l l were more a c t i v e than they were i n o t h e r seasons. Bears were a l s o more a c t i v e a c r o s s q u a r t e r day p e r i o d s i n the b e r r y season than they were i n the e a r l y summer, except between 2300 - 0500 hours ( F i g . 14). The second o r d e r i n t e r a c t i o n was complex ( F i g . 15a - d ) . With r e s p e c t t o se a s o n a l a c t i v i t y budgets, sex-age c l a s s e s tended t o be l e s s a c t i v e a c r o s s q u a r t e r day p e r i o d s i n t he s p r i n g than i n e a r l y summer o r the b e r r y season except between 1100 - 1700 hours. During t h i s q u a r t e r day p e r i o d , s p r i n g and e a r l y summer a c t i v i t y l e v e l s o v e r l a p p e d c o n s i d e r a b l y , w h i l e o n l y the low a c t i v i t y l e v e l o f a d u l t females i n the b e r r y season overlapped w i t h s p r i n g a c t i v i t y l e v e l s . In the f a l l , bears were l e s s a c t i v e i n the q u a r t e r day p e r i o d s encompassing 0500 - 1100 and 1700 - 2300 hours, IOO-I 90- 0500-1100 1100-1700 1700-2300 2300-0500 QUARTER DAY PERIOD F i g u r e 14. F i r s t o r d e r i n t e r a c t i o n between seasons and q u a r t e r day p e r i o d s from A n a l y s i s o f V a r i a n c e o f g r i z z l y bear a c t i v i t y budgets over seasons (Table 9 ) . P l o t t e d v a l u e s are p r e d i c t e d c e l l means. vo o u. O 0600-1)00 1100-1700 fTOO-2300 23OO-0GOO QUARTER DAY PERIOD no tO M 70 to 60 40 30 20- 10- 0 0600-1100 1100-1700 1700-2300 2300-0600 OUARTER DAY PERIOD HX) (0 80 70 80 SO 40- 30- 20 10 b wo to BO 70 to 60 40 30- 20- 10 0 0600-1100 1100-1700 1700-2300 2300-0600 OUARTER DAY PERIOD 0600-1100 1100-1700 1700-2300 2300-0600 OUARTER DAY PERIOD Sex-Age Class subadult males subadult females adult females F i g u r e 15. Second order i n t e r a c t i o n between seasons, SA c l a s s e s , and qu a r t e r day peri o d s from A n a l y s i s of Va r i a n c e of g r i z z l y bear a c t i v i t y budgets over seasons (Table 9). SA c l a s s x d i e l p e r i o d i n t e r a c t i o n s are p l o t t e d f o r a) sp r i n g , b) e a r l y summer, c) the b e r r y season, and d) f a l l . P l o t t e d v a l u e s are p r e d i c t e d c e l l means. 92 but tended t o be more a c t i v e between 2300 - 0500 hours, than they were i n e a r l y summer o r the b e r r y season. Between 1100 - 1700 hours, the a c t i v i t y l e v e l f o r s u b a d u l t females i n the f a l l exceeded e a r l y summer a c t i v i t y l e v e l s , and a l s o exceeded the a c t i v i t y l e v e l f o r a d u l t females i n the b e r r y season. S p r i n g and f a l l a c t i v i t y l e v e l s o v e r l a p p e d c o n s i d e r a b l y w i t h the e x c e p t i o n o f t h e q u a r t e r day p e r i o d r a n g i n g from 2300 - 0500 hours f o r which bears were c o n s i s t e n t l y more a c t i v e i n the f a l l . A c t i v i t y l e v e l s f o r sex-age c l a s s e s i n e a r l y summer and the b e r r y season o v e r l a p p e d i n a l l q u a r t e r day p e r i o d s w i t h s u b a d u l t s i n e a r l y summer d i s p l a y i n g much h i g h e r a c t i v i t y l e v e l s between 1100 - 1700 hours than i n the b e r r y season. R e l a t i o n s h i p s between t h e sex-age c l a s s e s v a r i e d among seasons w i t h no c o n s i s t e n t t r e n d f o r one sex-age c l a s s t o e x h i b i t h i g h e r a c t i v i t y l e v e l s . Pooled over seasons and q u a r t e r day p e r i o d s , a c t i v i t y l e v e l s f o r each sex-age c l a s s were s i m i l a r ( f o r s u b a d u l t males 55.7 ± 2.8%, s u b a d u l t females 56.0 ± 2.4%, a d u l t females 54.6 ± 1.9%). However, p o o l e d over seasons and q u a r t e r day p e r i o d s , i n d i v i d u a l s v a r i e d g r e a t l y i n a c t i v i t y (range: 34.1 ± 5.4% t o 71.0 ± 3.4%). Comparisons between e a r l y summer and t h e b e r r y season, w i t h sex and age f a c t o r i a l , r e s u l t e d i n o n l y the main e f f e c t s o f q u a r t e r day p e r i o d s and i n d i v i d u a l bears been s i g n i f i c a n t (Table 11). However, both these main e f f e c t s , as w e l l as age and season, appeared i n s i g n i f i c a n t f i r s t o r d e r i n t e r a c t i o n s (Table 11). Only the main e f f e c t o f sex 93 T a b l e 11. Mixed model n e s t e d - f a c t o r i a l A n a l y s i s o f V a r i a n c e o f a c t i v i t y budgets f o r sex-age c l a s s e s o f g r i z z l y b ears over e a r l y summer and the b e r r y season. Source o f v a r i a t i o n d . f . M.S. F Season 1 0. 469 1. 822 Sex 1 0. 454 0. 767 Age 1 0. 638 1. 078 Quart e r Day 3 8. 997 109. 790 Bear(Sex x Age) 6 0. 591 7. 593 Season x Sex 1 <0. 001 <0. 001 Season x Age 1 0. 006 0. 024 Sex x Age 1 0. 083 0. 141 Sex x Quart e r Day 3 0. 192 2. 344 Age x Quart e r Day 3 0. 822 10. 027 Season x Bear(Sex x Age) 6 0. 258 3. 307 Season x Sex x Age 1 0. 396 1. 537 Season x Quart e r Day 3 0. 088 1. 584 Sex x Age x Quarter Day 3 0. 155 1. 895 Season x Sex x Quarte r Day 3 0. 118 2. 127 Season x Age x Quarte r Day 3 0. 106 1. 902 Season x Sex x Age x Quarter Day 3 0. 026 0. 470 Quarter Day x Bear(Sex x Age) 18 0. 082 1. 052 Season x Quarter Day x Bear(Sex x Age) 18 0. 056 0. 714 R e s i d u a l 312 0. 078 Prob. 0.226 a 0.4155* 0.339 <0.001 C <o.ooie 0.981 a 0.883 a 0.720 0.107 C <0.001 C 0.004 6 0.261 a 0.228 0.167 C 0.132 d 0.166 d 0.707 d 0.401 e 0.797 6 T o t a l 391 a T e s t e d a g a i n s t Season x Bear(Sex x Age Cl a s s ) T e s t e d a g a i n s t Bear(Sex x Age Cl a s s ) ^ T e s t e d a g a i n s t Quarter Day x Bear(Sex x Age Cl a s s ) T e s t e d a g a i n s t Season x Quarter Day x Bear(Sex x Age) e T e s t e d a g a i n s t R e s i d u a l 94 c o u l d be i n t e r p r e t e d and i n d i c a t e d no s i g n i f i c a n t d i f f e r e n c e between males (56.1 ± 2.2%) and females (63.1 ± 2.0%). The f i r s t o r d e r i n t e r a c t i o n between age c l a s s e s and q u a r t e r day p e r i o d s suggested t h a t s u b a d u l t s had h i g h e r a c t i v i t y l e v e l s than a d u l t s i n a l l q u a r t e r day p e r i o d s except between 2300 - 0500 ( F i g . 16). Pooled over q u a r t e r day p e r i o d s and seasons, a d u l t s were a c t i v e 56.6 ± 1.8% w h i l e s u b a d u l t s were a c t i v e 64.9 ± 2.3%. The f i r s t o r d e r i n t e r a c t i o n between seasons and i n d i v i d u a l s r e v e a l e d t h a t 4 i n d i v i d u a l s (1 a d u l t female, 1 a d u l t male, 2 suba d u l t females) e x h i b i t e d a d i s t i n c t i n c r e a s e (range o f a b s o l u t e d i f f e r e n c e s (RAD): 6.8 - 36.1%) i n a c t i v i t y from e a r l y summer t o t h e b e r r y season, 3 i n d i v i d u a l s (1 a d u l t female, 2 suba d u l t males) demonstrated l i t t l e d i f f e r e n c e (RAD: 0.6 - 2.3%) i n a c t i v i t y , and 3 i n d i v i d u a l s (1 a d u l t female, 1 a d u l t male, 1 su b a d u l t male) showed a d i s t i n c t decrease i n a c t i v i t y (RAD: 5.3 - 16.3%). Seasonal a c t i v i t y l e v e l s were 56.5 ± 2.0% f o r e a r l y summer and 63.8 ± 2.2% f o r the b e r r y season. DISCUSSION W i t h i n a s p e c i e s , an i n d i v i d u a l ' s t o t a l time a c t i v e and the d i s t r i b u t i o n o f a c t i v i t y over the d i e l c y c l e a r e determined by i n d i v i d u a l s p e c i f i c (e.g., weight, age, sex, p h y s i o l o g i c a l c o n d i t i o n ) and environmental (e.g., p r e d a t i o n , human a c t i v i t y , thermal s t r e s s , food type and abundance, a v a i l a b l e d a y l i g h t ) f a c t o r s (Bunnell and G i l l i n g h a m 1985). I F i g u r e 16. F i r s t o r d e r i n t e r a c t i o n between age c l a s s e s and q u a r t e r day p e r i o d s from A n a l y s i s o f V a r i a n c e o f g r i z z l y bear a c t i v i t y budgets f o r sex-age c l a s s e s over e a r l y summer and the b e r r y season (Table 10). P l o t t e d v a l u e s are p r e d i c t e d c e l l means. 96 I n d i v i d u a l f a c t o r s assessed i n t h i s study were r e s t r i c t e d t o sex and t o broad age c l a s s e s , although weight i s c o v a r i a t e w i t h both t h e s e f a c t o r s . Environmental f a c t o r s e x p l i c i t l y d e a l t w i t h were r e s t r i c t e d t o seasons (and hence, food type and abundance) and the d a i l y s o l a r c y c l e . Thermal s t r e s s and human a c t i v i t y tend t o be c o v a r i a t e w i t h seasons. Changes from the predominate s p r i n g and f a l l foods (Hedysarum sulphuresence and c a r r i o n ) t o g r a s s e s , f o r b s and b e r r i e s , were accompanied by a change i n thermal regime. S i m i l a r l y , use o f unroaded h i g h e l e v a t i o n b e r r y f i e l d s r e s u l t e d i n a s w i t c h t o b e r r i e s b e i n g accompanied by a change i n the l e v e l of human d i s t u r b a n c e . A c t i v i t y P a t t e r n s Most r e s e a r c h supports a g e n e r a l d e s c r i p t i o n o f g r i z z l y bears as n o c t u r n a l or c r e p u s c u l a r , w i t h a c t i v i t y peaks i n the mornings and evenings, and o f t e n h i g h e r a c t i v i t y l e v e l s d u r i n g the n i g h t than d u r i n g the day (Clevenger e t a l . 1990; Gunther 1990; P h i l l i p s 1987; Roth and Huber 1987; Roth and Huber 1986; Aune and S t i v e r s 1985; H a r t i n g 1985; Aune e t a l . 1984; Roth 1983; S c h l e y e r 1983). S u b s t a n t i a l v a r i a t i o n i n a c t i v i t y p a t t e r n s has been r e p o r t e d among and w i t h i n i n d i v i d u a l s (Clevenger e t a l . 1990; Aune and Kasworm 1989; Roth and Huber 1986; H a r t i n g 1985; H e c h t e l 1985; Roth 1983; S c h l e y e r 1983; Sizemore 1980), and among seasons, where se a s o n a l i n f o r m a t i o n i s a v a i l a b l e ( H a r t i n g 1985; S c h l e y e r 1983; Gebhard 1982; Sizemore 1980). Some authors have 97 r e l a t e d observed d i u r n a l a c t i v i t y t o reduced l e v e l s o f human i n t r u s i o n o r t o use o f h a b i t a t s t h a t have h i g h cover v a l u e (Clevenger e t a l . 1990; Aune and Kasworm 1989; B j a r v a l l and Sandegren 1987). Many have suggested t h a t observed n o c t u r n a l o r c r e p u s c u l a r a c t i v i t y i s a b e h a v i o r a l a d a p t a t i o n t o a v o i d humans. U n l i k e most o t h e r s t u d i e s of g r i z z l y bear a c t i v i t y p a t t e r n s , bears i n the F l a t h e a d were p r i m a r i l y a c t i v e d u r i n g d a y l i g h t hours. While a c t i v i t y l e v e l s expressed i n d i e l p e r i o d s f r e q u e n t l y d i d not suggest s t r o n g b i m o d a l i t y , p l o t s o f h o u r l y a c t i v i t y l e v e l s u t i l i z i n g a l l data ( F i g s . 17 - 20) g e n e r a l l y d i d d i s p l a y a bimodal a c t i v i t y p a t t e r n w i t h peaks i n the morning and evening. Morning a c t i v i t y peaks, however, were o f t e n not c e n t e r e d about s u n r i s e but r a t h e r o c c u r r e d 1 o r more h a f t e r s u n r i s e . Evening a c t i v i t y peaks showed a c l o s e r r e l a t i o n s h i p t o sunset. Reported i n f l u e n c e s of seasons on d i e l a c t i v i t y p a t t e r n s o f bears are ambiguous. S c h l e y e r (1983) and H a r t i n g (1985) observed Yellowstone g r i z z l i e s t o be more d i u r n a l i n s p r i n g and f a l l than i n summer. Sizemore (1980) found g r i z z l i e s i n the southern F l a t h e a d area t o be more n o c t u r n a l i n the spring-summer season, but found no d i f f e r e n c e s i n d i u r n a l and n o c t u r n a l a c t i v i t y i n t h e summer- f a l l season. Some s t u d i e s on European brown bears (Clevenger e t a l . 1990; Roth and Huber 1986) have r e p o r t e d d i u r n a l a c t i v i t y by i n d i v i d u a l bears i n f a l l and w i n t e r , but i n d i v i d u a l s d i d not show c o n s i s t e n t p a t t e r n s a c r o s s y e a r s . KK) n 4 6 8 7 8 9 10 11 12 13 HIS 16 17 18 19 20 2122 23 24 ^ TTME OF DAY ^ 1 2 3 4 B 6 7 8 9 10 11 12 13 14 1B 16 17 18 19 20 21 22 23 24 A. TIME OF DAY A. 100- 90- 80- G TO" < LU 60 2 fe... LU O 30 E 20 10- 0 tm i i II IP 11 I I l l l 1 2 3 4 6 8 • i i i i 1 iliPIII III! M i l l II 7 8 9 10 11 12 13 14 IB 18 17 18 19 20 2122 23 24 TIME 6F DAY ^ F i g u r e 17. Percent of time a c t i v e by hour of the day i n s p r i n g f o r a) s u b a d u l t females, b) a d u l t females, and c) sub a d u l t males. Arrows i n d i c a t e approximate times of s u n r i s e and sunset. P l o t s were composed from a l l s p r i n g data c o l l e c t e d . For hours of the day, 1 = 0000-0100; 2 = 0100-0200 et c . vo 00 1 2 3 4 6 8 7 8 9 to 11 12 13 14 18 18 17 18 t9 20 21 22 23 24 ^ TIME OF DAY ^ TOO 80- 80- R 70- Uj 80 E - o g 40 O 30 20 10 0 I I 1 I I I i l i l l i l l II1 I I 1 III i l i i 11 n i l • f t I 11 il i n h i i n 1 2 3 4 B 8 7 8 9 10 11 T2 13 14 16 18 17 18 19 20 2122 23 24 ^ TIME OF DAY ^ F i g u r e 18. Percent o f time a c t i v e by X females, b) a d u l t females, i n d i c a t e approximate times from a l l e a r l y summer data 2 = 0100-0200 e t c . 100 90 -| LU 8 0 < Ul 80 2 u. O 60 40 30- 20- 10 0 1 mt m J i IH 1 H I §§11 i i 1 l l l l l l ! W i l l I I II 1 2 3 4 6 8 7 8 9 10 11 12 13 14 18 16 17 18 19 20 21 22 23 24 ^ TIME OF 0AY ^ TOO 90 < Ul 80 5 u. O 60 H 40 30- 20- 10 0 d II i l ^ ̂  ̂  ̂  ̂  i n pin • V I 11 H i _ II i i HI iiii i i i l l 2 3 4 6 8 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2122 23 24 ^ TIME OF DAY ^ Lour of the day i n e a r l y summer f o r a) s u b a d u l t c) subadult males, and d) a d u l t males. Arrows of s u n r i s e and sunset. P l o t s were composed c o l l e c t e d . For hours o f the day, 1 = 0000-0100; 100- 90- UJ B0- F 70- < LU 80-2 E - o fc- *0 S 20- 10- n ' i 1 1 11 l III 0 -J-J 100-. 90- U, BO- S' ro- < LU 60- 5 E - o y 30- E 20- 10- I o-U r'T*'v'i"f"r"Y"r'i t" 1 2 3 4 6 8 7 6 9 10 j 11 12 13 14 16 18 17 1 ME OF DAY M 3 192 I I 0 212 I Hi 1 2324 ll 1 2 3 4 5 8 7 8 9 10 11 12 13 14 16 18 17 18 19 20 21 22 23 24 A TIME OF DAY & F i g u r e 19. Percent of time a c t i v e by hour of subadult females, b) a d u l t female Arrows i n d i c a t e approximate times composed from a l l b e r r y season da 1 = 0000-0100; 2 = 0100-0200 e t c . 100 90- Uj 80- > < LU 60 2 o |_ 40 S 20 10 0 i l l II i i i i i i i i i i i i i i l l l l l l l l l l l l l l l l l .1 i i i l l l I P iiiiiniiiiini Y- Y. V. ' / / / / , V. Y. II -•ii M l 1 2 3 4 5 6 7 8 9 10 11 12 13 14 IS 16 17 18 19 20 21 22 23 24 A TIME OF DAY A 100 80 Uj 8° > 0 70 < UJ 60-| o |- 40 LU O 30- S 20- 10- I P i i | | i | I •••••••••1 i ^ WPP m i l i l l 1 2 3 4 5 8 7 8 9 10 11 12 13 14 16 18 17 18 19 20 21 22 23 24 A TIME OF DAY A the day i n the b e r r y season f o r a) , c) suba d u l t males, and d) a d u l t males. of s u n r i s e and sunset. P l o t s were a c o l l e c t e d . For hours o f the day, too 80- 70- »0 O 20- 11 m I I I I i l II J i l l " in•in i i pEL III HI II II II in I I i 2 3 4 6 6 7 8 9 10 11 12 13 14 15 18 T7 18 19 20 21222324 A TIME OF DAY A 100-i 2 3 4 5 8 7 8 9 10 11 12 1314 15 18 17 18 18 20 21222324 TIME OF DAY A T LU 100 80 G 7 0 < Ul 80 o 8 60- 40- 30 20- 10 0 L • • • l l l i p i l l M i i l i Hi 11 J 2 3 4 5 8 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21222324 A TIME OF DAY A F i g u r e 2 0 . Percent of time a c t i v e by hour of the day i n f a l l f o r a) subadult females, b) a d u l t females, and c) subadult males. Arrows i n d i c a t e approximate times of s u n r i s e and sunset. P l o t s were composed from a l l f a l l data c o l l e c t e d . For hours of the day, 1 = 0 0 0 0 - 0 1 0 0 ; 2 = 0 1 0 0 - 0 2 0 0 e t c . 102 In s p i t e o f s p r i n g and f a l l b e i n g s i m i l a r i n primary foods u t i l i z e d by bears, I found g r i z z l i e s i n the F l a t h e a d t o e x h i b i t t h e lowest n o c t u r n a l a c t i v i t y l e v e l s i n the s p r i n g and the h i g h e s t n o c t u r n a l a c t i v i t y i n the f a l l . A v a i l a b l e d a y l i g h t was s h o r t e r i n t h e f a l l and may c o n t r i b u t e t o t h i s r e s u l t . The a v a i l a b i l i t y o f c a r r i o n i n the f a l l i s p r i m a r i l y a f u n c t i o n o f s p o r t h u n t i n g (gut p i l e s from hunter k i l l s and c r i p p l e d animals) w h i l e s p r i n g c a r r i o n i s from w i n t e r k i l l s and w i n t e r weakened animals. Throughout most of t he year, human i n t r u s i o n i s p r e d i c t a b l e and c e n t e r e d a l o n g the network o f roads, w h i l e i n the f a l l , b ears have a much h i g h e r p r o b a b i l i t y o f e n c o u n t e r i n g hunters away from roads. The g r e a t e r a c t i v i t y by bears d u r i n g darkness i n the f a l l may be an avoidance r e a c t i o n t o hunter a c t i v i t y , but may a l s o r e l a t e t o bears s e a r c h i n g f o r remains o f hunter k i l l s a t n i g h t when h u n t i n g a c t i v i t y i s low. M c L e l l a n and Shac k l e t o n (1988) found t h a t g r i z z l y bears used areas c l o s e (0 - 250 m) t o roads s i g n i f i c a n t l y l e s s than expected i n the F l a t h e a d and t h a t t h i s r e p r e s e n t e d an 8.7% l o s s o f a v a i l a b l e h a b i t a t . They a l s o found t h a t bears used areas near roads more o f t e n a t n i g h t than d u r i n g the day. H a b i t a t s c l o s e t o roads (e.g., r i p a r i a n areas) tended t o be o f h i g h v a l u e t o bears i n s p r i n g , e a r l y summer, and f a l l . T h i s study, however, i n d i c a t e s t h a t b ears have not made a s i g n i f i c a n t s h i f t i n t h e i r a c t i v i t y p a t t e r n s t o enable them t o e x p l o i t h a b i t a t s near roads and suggests t h a t 103 adequate amounts o f h a b i t a t f u r t h e r away from roads are a v a i l a b l e t o support c u r r e n t p o p u l a t i o n l e v e l s . S e v e r a l authors have suggested t h a t g r i z z l i e s a re more a c t i v e d u r i n g d a y l i g h t hours i n environments w i t h low human i n t r u s i o n (Aune and S t i v e r s 1989; B j a r v a l l and Sandegren 1987; Roth and Huber 1986; Roth 1983). Strong evidence i n d i c a t i n g h i g h use o f d a y l i g h t hours as normal f o r g r i z z l i e s has g e n e r a l l y been l a c k i n g . R e s u l t s o f t h i s study support a p r e f e r e n c e f o r d i u r n a l a c t i v i t y i n an environment where human i n t r u s i o n i s h i g h l y l o c a l i z e d around roads and hence, i s p r e d i c t a b l e i n space. P r e f e r e n c e s f o r d a y l i g h t may be r e l a t e d t o i n c r e a s e d o p p o r t u n i t i e s f o r s e l e c t i v e f o r a g i n g (Bunnell and G i l l i n g h a m 1985), or t o i n c r e a s e d s e a r c h i n g e f f i c i e n c y . C u r r e n t l y , i t i s u n c l e a r i f g r i z z l y p o p u l a t i o n s r e s t r i c t e d t o n o c t u r n a l f o r a g i n g e x p l o i t r e s o u r c e s l e s s e f f e c t i v e l y than they would w i t h d i u r n a l f o r a g i n g p a t t e r n s . A c t i v i t y Budgets Comparing se a s o n a l a c t i v i t y l e v e l s found i n t h i s study w i t h o t h e r r e s e a r c h on g r i z z l y bear a c t i v i t y budgets i s d i f f i c u l t due t o d i f f e r i n g d e f i n i t i o n s o f seasons a c r o s s s t u d i e s . These d i f f e r e n c e s , i n p a r t , r e f l e c t g e o g r a p h i c a l v a r i a t i o n i n food r e s o u r c e s , p l a n t p h e n o l o g i c a l development, and d u r a t i o n o f the denning p e r i o d . For the Yellowstone g r i z z l y p o p u l a t i o n , S c h l e y e r (1983) found a c t i v i t y l e v e l s t o be the lowest (approx. 2.4 - 4.8 hours o f a c t i v i t y p e r 24- 104 hour p e r i o d , o r 10 - 20% TA) i n p o s t - and pre-denning months (March, and September and Oc t o b e r ) . A c t i v i t y l e v e l s were h i g h i n A p r i l , June, J u l y , and August (approx. 8.0 - 12.0 hours o f a c t i v i t y per 24-hour p e r i o d , o r 33 - 50% TA). G r i z z l i e s were found t o be the most a c t i v e i n May, but data were not thought t o be r e p r e s e n t a t i v e . H a r t i n g (1985) a l s o s t u d i e d t h e a c t i v i t y p a t t e r n s o f Yellowstone g r i z z l i e s and a l s o found a c t i v i t y l e v e l s t o be h i g h i n the summer months ( p r o b a b i l i t y o f a c t i v i t y : 0.64 - 0.71) and lower i n September (0.52). In c o n t r a s t t o S c h l e y e r ' s (1983) r e s u l t s , bears were l e a s t a c t i v e i n May (0.52). In the southern F l a t h e a d r e g i o n , Sizemore (1980) r e p o r t e d g r i z z l y bear a c t i v i t y l e v e l s t o be s i g n i f i c a n t l y lower i n the s p r i n g - summer p e r i o d (den emergence t o J u l y 31) than i n t h e summer- f a l l p e r i o d (August 1 t o den e n t r y ) . For n o r t h e r n A l a s k a n g r i z z l y p o p u l a t i o n s , Gebhard (1982) found t h e a c t i v i t y l e v e l of a f a m i l y u n i t t o be 58% d u r i n g s p r i n g , e a r l y summer and l a t e summer, 71% i n e a r l y f a l l , and 83% i n l a t e f a l l . H e c h t e l (1985), however, d i d not f i n d a se a s o n a l t r e n d f o r i n c r e a s e d a c t i v i t y i n the f a l l by t h i s same f a m i l y u n i t i n the f o l l o w i n g year. I n f o r m a t i o n on monthly o r sea s o n a l a c t i v i t y l e v e l s o f European brown bears i s l i m i t e d . Roth (1983) found brown bears i n n o r t h e r n I t a l y t o be a c t i v e 45 - 60% o f the time i n summer and f a l l . While data d i d not permit s e p a r a t i o n o f se a s o n a l t r e n d s from i n d i v i d u a l v a r i a b i l i t y , Roth (1983) noted t h a t the da t a weakly suggested h i g h a c t i v i t y l e v e l s i n 105 summer and somewhat lower a c t i v i t y l e v e l s i n f a l l . A s u b a d u l t female brown bear i n Y u g o s l a v i a spent about 60% of the time i n a c t i v i t y from J u l y t o October dropping t o about 40% o f t h e time i n November and December (Roth and Huber 1986). From a l a r g e r sample o f brown bears i n Y u g o s l a v i a , Roth and Huber (1987) found a c t i v i t y l e v e l s t o be h i g h e s t i n May (64%) and September (58%) w i t h h i g h a c t i v i t y l e v e l s m a i n t a i n e d d u r i n g the i n t e r v e n i n g months. Data f o r an a d u l t male brown bear i n Spain (Clevenger e t a l . 1990) showed a c t i v i t y l e v e l s t o be lowest (31%) i n the post-denning p e r i o d (den emergence t o May 15), h i g h e s t (43%) i n the b r e e d i n g season (May 16 t o August 31), and s l i g h t l y lower (39%) i n f a l l / w i n t e r (September 1 t o den e n t r y ) . Most data thus support a seasonal t r e n d i n g r i z z l y bear a c t i v i t y budgets, w i t h p o s t - and pre-denning p e r i o d s b e i n g the l e a s t a c t i v e . T h i s t r e n d i s i n accordance w i t h the b e a r s ' annual p h y s i o l o g i c a l phases proposed by Nelson e t a l . (1983). The post-denning hypophagic p e r i o d i s c h a r a c t e r i z e d by a p e r s i s t e n c e i n the b i o c h e m i c a l changes a s s o c i a t e d w i t h denning f o r up t o 3 weeks a f t e r den emergence. Bears then e n t e r a p e r i o d o f normal a c t i v i t y , f o l l o w e d by hyperphagic a c t i v i t y . The t i m i n g o f hyperphagic b e h a v i o r can be expected t o v a r y between geographic areas r e l a t i v e t o the a v a i l a b i l i t y o f abundant, h i g h q u a l i t y food r e s o u r c e s . A s s e s s i n g the e x t e n t of the hyperphagic p e r i o d from a c t i v i t y budget d a t a may be d i f f i c u l t . The low a c t i v i t y l e v e l s of g r i z z l i e s i n f a l l observed by S c h l e y e r (1983), were 106 a t t r i b u t e d t o them f e e d i n g on un g u l a t e s . Bears were found t o be s i g n i f i c a n t l y l e s s a c t i v e when u t i l i z i n g c a r c a s s e s than when u s i n g o t h e r foods ( S c h l e y e r 1983), however, i n g e s t i o n r a t e s by bears are h i g h when f e e d i n g on c a r c a s s e s and i t i s u n c l e a r i f t h e r e was a r e d u c t i o n i n e n e r g e t i c i n t a k e a s s o c i a t e d w i t h the lower a c t i v i t y l e v e l s . In t h i s study, expected t r e n d s i n sea s o n a l a c t i v i t y l e v e l s were f o r s p r i n g and f a l l t o be the l e a s t a c t i v e seasons due t o post-denning hypophagic b e h a v i o r , and the h i g h use o f c a r r i o n i n both seasons. Higher a c t i v i t y l e v e l s were expected i n e a r l y summer as bears e n t e r e d the normal a c t i v i t y phase. The b e r r y season r e p r e s e n t e d a p e r i o d o f abundant, h i g h q u a l i t y food and r e s u l t a n t hyperphagic b e h a v i o r coupled w i t h l o n g h a n d l i n g times was expected t o i n c r e a s e a c t i v i t y l e v e l s . Expected t r e n d s i n a c t i v i t y l e v e l s over seasons were met f o r a n a l y s e s both over a l l 4 seasons, and over e a r l y summer and the b e r r y season. Higher a c t i v i t y i n e a r l y summer and t h e b e r r y season, as compared t o s p r i n g and f a l l , appeared t o be a c o n s i s t e n t t r e n d over sex-age c l a s s e s and i n d i v i d u a l s . An i n c r e a s e i n a c t i v i t y l e v e l s from e a r l y summer t o the b e r r y season was not c o n s i s t e n t over sex-age c l a s s e s o r i n d i v i d u a l s . A t the l e v e l o f sex-age c l a s s e s , o n l y subadult females and a d u l t males showed the p r e d i c t e d i n c r e a s e i n a c t i v i t y . However, the i n t e r a c t i o n between i n d i v i d u a l s and seasons i n the a n a l y s i s over e a r l y summer and the b e r r y season, i n d i c a t e d t h a t w h i l e i n d i v i d u a l s ubadult females responded s i m i l a r l y , 107 a d u l t males d i d not. Male #25's a c t i v i t y l e v e l i n c r e a s e d from 36.9% i n e a r l y summer t o 73.0% i n the b e r r y season, w h i l e male #65's a c t i v i t y l e v e l decreased from 41.9% i n e a r l y summer t o 25.6% i n the b e r r y season. T h i s c o n t r a s t i n a c t i v i t y l e v e l s was accompanied by i n d i v i d u a l d i f f e r e n c e s i n f o r a g i n g s t r a t e g i e s , as male #65 u t i l i z e d r i p a r i a n r i v e r bottoms i n the b e r r y season r a t h e r than h i g h e l e v a t i o n b e r r y f i e l d s l i k e o t h e r bears. T h i s suggests t h a t s i z e o r frequency dependent d i f f e r e n c e s i n f o r a g i n g s t r a t e g i e s e x i s t and as a consequence, the importance of the b e r r y r e s o u r c e t o i n d i v i d u a l s i s not r e l a t i v e l y the same among sex-age c l a s s e s . S i n c e s u b a d u l t females are the most s o c i a l and p h y s i c a l l y s u b o r d i n a t e c l a s s o f bears, and are l i k e l y poor c o m p e t i t o r s f o r food r e s o u r c e s , l o s s o f a l a r g e , abundant, temporal r e s o u r c e t h a t i s not defendable by dominant i n d i v i d u a l s , may have t h e g r e a t e s t e f f e c t on s u b a d u l t females. Pooled over e a r l y summer and the b e r r y season, females tended t o be more a c t i v e than males, and s u b a d u l t s tended t o be more a c t i v e than a d u l t s . In t h e i r review o f mammalian a c t i v i t y budgets, B u n n e l l and Harestad (1989) found a g e n e r a l tendency a c r o s s s p e c i e s f o r a d u l t males t o be l e s s a c t i v e than a d u l t females, even when r e p r o d u c t i v e l y a c t i v e males and pregnant or l a c t a t i n g females were excluded from t h e a n a l y s e s . S i z e - r e l a t e d d i f f e r e n c e s i n s e l e c t i v i t y , and i n the case o f l a r g e h e r b i v o r e s , l a r g e r b i t e s i z e p e r m i t t i n g more r a p i d i n g e s t i o n r a t e s , were suggested as p o s s i b l e 108 c o n t r i b u t i n g f a c t o r s t o t h i s r e s u l t . In the case of bears, s i z e - r e l a t e d d i f f e r e n c e s i n access t o h i g h q u a l i t y food r e s o u r c e s may be more important i n e x p l a i n i n g b o t h d i f f e r e n c e s between males and females, and between a d u l t s and s u b a d u l t s . I n c r e a s e d e n e r g e t i c requirements f o r growth, cou p l e d w i t h p o t e n t i a l f o r a g i n g i n e f f i c i e n c i e s ( Bunnell and G i l l i n g h a m 1985) by s u b a d u l t s may a l s o be important. I n t e r e s t i n g l y , among sup e r c o n c e n t r a t e (e.g., mast) f e e d e r s , B u n n e l l and Harestad (1989) concluded t h a t time advantages a c c r u i n g t o males due t o t h e i r l a r g e r s i z e would be l o s t i f they c o u l d not secure p r o f i t a b l e patches f o r themselves. The h i g h a c t i v i t y l e v e l o f bear #25 i n the b e r r y season may be c o n s i s t e n t w i t h t h i s o b s e r v a t i o n i f bears f o r a g i n g i n the l a r g e b e r r y f i e l d s o f the F l a t h e a d V a l l e y have equal access t o the same d i s t r i b u t i o n o f food p a t c h q u a l i t y . While r e s u l t s f o r sex and age c l a s s e s over t h e e a r l y summer and the b e r r y season met e x p e c t a t i o n s , i t appeared t o be p r i m a r i l y dependent on the i n f l u e n c e o f low a c t i v i t y l e v e l s by a d u l t males i n the e a r l y summer and on the h i g h a c t i v i t y l e v e l o f s u b a d u l t females i n the b e r r y season. A c t i v i t y l e v e l s p o o l e d over a l l 4 seasons showed no t r e n d s a t t r i b u t a b l e t o sex-age c l a s s e f f e c t s . Over t h e i r e n t i r e a c t i v e p o r t i o n o f the year, a d u l t females and s u b a d u l t s of both sexes were a c t i v e about the same amount o f time. 109 LITERATURE CITED A r c h i b a l d , W. R., R. E l l i s , and A. N. Hamilton. 1987. Responses o f g r i z z l y bears t o l o g g i n g t r u c k t r a f f i c i n the K imsquit R i v e r v a l l e y , B r i t i s h Columbia. I n t . Conf. Bear Res. and Manage. 7:251-257. Aune, K., T. S t i v e r s , and M. Madel. 1984. Rocky Mountain f r o n t g r i z z l y bear m o n i t o r i n g and i n v e s t i g a t i o n . Mont. Dep. F i s h , W i l d l . and Parks. Helena, Montana. 239 pp. Aune, K., and T. S t i v e r s . 1985. E c o l o g i c a l s t u d i e s o f t h e g r i z z l y bear i n the Pine Butte P r e s e r v e . Mont. Dep. F i s h , W i l d l . and Parks. Helena, Montana. 154 pp. Aune, K., and W. Kasworm. 1989. F i n a l r e p o r t : e a s t f r o n t g r i z z l y bear study. Mont. Dep. F i s h , W i l d l . and Parks. Helena, Montana. 332 pp. B j a r v a l l , A., and F. Sandegren. 1987. E a r l y e x p e r i e n c e s w i t h the f i r s t radio-marked brown bears i n Sweden. I n t . Conf. Bear Res. and Manage. 7:9-12. Boy, V., and P. Duncan. 1979. Time-budgets o f Camargue ho r s e s . 1. Developmental changes i n the time-budgets of f o a l s . Behaviour 71:187-202. B u n n e l l , F. L., and M. P. G i l l i n g h a m . 1985. F o r a g i n g b e h a v i o r : dynamics of d i n i n g out. In B i o e n e r g e t i c s o f w i l d h e r b i v o r e s . E d i t e d by. R. J . Hudson and R. G. White. CRC Press, Boca Raton, F l o r i d a , pp. 53-79. B u n n e l l F. L., and A. S. Harestad. 1989. A c t i v i t y budgets and body weight i n mammals: how sloppy can mammals be? Curr . Mammal. 2:245-305. Clevenger, A. P., F. J . Purroy, and M. R. P e l t o n . 1990. Movement and a c t i v i t y p a t t e r n s o f a European brown bear i n t he C a n t a b r i a n Mountains, Spain. I n t . Conf. Bear. Res. and Manage. 8:205-211. Eberhardt, L. L. 1977. "Optimal" management p o l i c i e s f o r marine mammals. W i l d l . Soc. B u l l . 5:162-169. 110 Gebhard, J . G. 1982. Annual a c t i v i t i e s and b e h a v i o r o f a g r i z z l y bear (Ursus a r c t o s ) f a m i l y i n n o r t h e r n A l a s k a . M.Sc. T h e s i s . Univ. A l a s k a , F a i r b a n k s , A l a s k a . 218 pp. G e i s t , V. 1971. Bighorn sheep b i o l o g y . W i l d l . Soc. News. 136:61. G r i e g , M., and J . B j e r r i n g . 1978. UBC GENLIN - a g e n e r a l l e a s t squares a n a l y s i s o f v a r i a n c e program. Computing Centre. Univ. o f B r i t i s h Columbia, Vancouver, B r i t i s h Columbia. 48 pp. Gunther, K. A. 1990. V i s i t o r impact on g r i z z l y bear a c t i v i t y i n P e l i c a n V a l l e y , Yellowstone N a t i o n a l Park. I n t . Conf. Bear Res. and Manage. 8:73-78. Harding, L., and J . A. Nagy. 1980. Responses of g r i z z l y b e a rs t o hydrocarbon e x p l o r a t i o n on R i c h a r d s I s l a n d , Northwest T e r r i t o r i e s , Canada. I n t . Conf. Bear Res. and Manage. 4:277-280. H a r t i n g , A. L. 1985. R e l a t i o n s h i p s between a c t i v i t y p a t t e r n s and f o r a g i n g s t r a t e g i e s o f Yellowstone g r i z z l y b e a r s . M.Sc. T h e s i s , Mont. S t a t e Univ., Bozeman, Montana. 103 pp. H e c h t e l , J . L. 1985. A c t i v i t y and food h a b i t s o f b a r r e n - ground g r i z z l y bears i n A r c t i c A l a s k a . M.Sc. T h e s i s . Univ. Montana, M i s s o u l a , Montana. 74 pp. H i c k s , C. R. 1982. Fundamental concepts i n the d e s i g n o f experiments. 3rd edn. H o l t , R i n e h a r t and Winston, New York, New York. 425 pp. Jacobsen, N. K., and A. D. Wiggins. 1982. Temporal and p r o c e d u r a l i n f l u e n c e s on a c t i v i t y e s t i m a t e d by time- sampling. J . W i l d l . Manage. 46:313-324. Knight, R. R. 1980. B i o l o g i c a l c o n s i d e r a t i o n s i n the d e l i n e a t i o n o f c r i t i c a l h a b i t a t . I n t . Conf. Bear Res. and Manage. 4:1-3. I l l Mattson, D. J . , R. R. Knight, and B. M. Blanchard. 1987. The e f f e c t s o f developments and primary roads on g r i z z l y bear h a b i t a t use i n Yellowstone N a t i o n a l Park, Wyoming. I n t . Conf. Bear Res. and Manage. 7:259-273. M c L e l l a n , B. N. 1989. Dynamics o f a g r i z z l y bear p o p u l a t i o n d u r i n g a p e r i o d o f i n d u s t r i a l r e s o u r c e e x t r a c t i o n . I I I . N a t a l i t y and r a t e o f i n c r e a s e . Can. J . Z o o l . 67:1865- 1868. M c L e l l a n , B. N., and D. M. Shac k l e t o n . 1988. G r i z z l y bears and r e s o u r c e - e x t r a c t i o n i n d u s t r i e s : e f f e c t s o f roads on behaviour, h a b i t a t use and demography. J . A p p l . E c o l . 25:451-460. M c L e l l a n , B. N., and D. M. Shackleton. 1989a. G r i z z l y bears and r e s o u r c e - e x t r a c t i o n i n d u s t r i e s : h a b i t a t displacement i n response t o s e i s m i c e x p l o r a t i o n , timber h a r v e s t i n g and road maintenance. J . A p p l . E c o l . 26:371- 380. M c L e l l a n , B. N., and D. M. Shackleton. 1989b. Immediate r e a c t i o n s o f g r i z z l y bears t o human a c t i v i t i e s . W i l d l . Soc. B u l l . 17:269-274. Nelson, R. A . , G. E . F o l k , E . w. P f e i f f e r , J . J . Craighead, C. J . J o n k e l , and D. L. S t e i g e r . 1983. Behavior, b i o c h e m i s t r y , and h i b e r n a t i o n i n b l a c k , g r i z z l y , and p o l a r b e a r s . I n t . Conf. Bear Res and Manage. 5:284-290. P h i l l i p s , M. K. 1987. Behavior and h a b i t a t use o f g r i z z l y b ears i n n o r t h e a s t e r n A l a s k a . I n t . Conf. Bear Res. and Manage. 7:159-167. Roth, H. U. 1983. D i e l a c t i v i t y o f a remnant p o p u l a t i o n o f European brown bears. I n t . Conf. Bear Res. and Manage. 5:223-229. Roth, H. U., and D. Huber. 1986. D i e l a c t i v i t y o f brown bears i n P l i t v i c e Lakes N a t i o n a l Park, Y u g o s l a v i a . I n t . Conf. Bear Res. and Manage. 6:177-181. 112 Roth, H. U., and D. Huber. 1987. P a t t e r n s o f amount o f a c t i v i t y o f brown bears i n Y u g o s l a v i a . A b s t r . from T h i r d Congr. o f the C r o a t i a n B i o l . S o c , M a l i L o s i n j , Y u g o s l a v i a . S c h l e y e r , B. 0. 1983. A c t i v i t y p a t t e r n s o f g r i z z l y bears i n the Yellowstone ecosystem and t h e i r r e p r o d u c t i v e b e h a v i o r , p r e d a t i o n and use o f c a r r i o n . M.Sc. T h e s i s , Mont. S t a t e Univ., Bozeman, Montana. 130 pp. Servheen, C. 1981. G r i z z l y bear ecology and management i n the M i s s i o n Mountains, Montana. Ph.D. T h e s i s , Univ. o f Montana, M i s s o u l a , Montana. 139 pp. Sizemore, D. L. 1980. F o r a g i n g s t r a t e g i e s o f the g r i z z l y bear as r e l a t e d t o i t s e c o l o g i c a l e n e r g e t i c s . M.Sc. T h e s i s , Univ. of Montana, M i s s o u l a , Montana. 67 pp. So k a l , R. R., and F. J . R o h l f . 1981. Biometry. 2nd edn. W. H. Freeman and Co., New York, New York. 859 pp. CHAPTER 5: OVERALL CONCLUSIONS Human a c t i v i t i e s can a f f e c t g r i z z l y bears i n many ways. The p o t e n t i a l n e g a t i v e consequences of human a c t i v i t i e s on g r i z z l i e s can be c l a s s i f i e d b r o a d l y i n t o d i r e c t and i n d i r e c t impacts. D i r e c t impacts tend t o be immediate, extreme, and r e s u l t i n bear m o r t a l i t i e s from h u n t i n g , poaching, problem bear c o n t r o l , and a c c i d e n t s a l o n g roadways. I n d i r e c t impacts a re a s s o c i a t e d w i t h environmental m o d i f i c a t i o n s t h a t u l t i m a t e l y express themselves as changes i n the be h a v i o r , i n the energy s t a t u s o f the p o p u l a t i o n , o r i n both. D e s t r u c t i o n o r a l t e r a t i o n o f important h a b i t a t s a r e fre q u e n t consequences o f human se t t l e m e n t , a g r i c u l t u r e , and r e s o u r c e e x t r a c t i o n . D i s t u r b a n c e from human i n t r u s i o n may r e s u l t i n c o s t l y f l i g h t responses by bears, r e s u l t i n bears a v o i d i n g h a b i t a t s c l o s e t o areas o f human a c t i v i t y , o r cause bears t o a l t e r t h e i r d a i l y rhythms o f a c t i v i t y and i n a c t i v i t y . I f severe enough, i n d i r e c t impacts may l e a d t o d e c l i n e s i n p o p u l a t i o n s i z e and p r o d u c t i v i t y . The u l t i m a t e y a r d s t i c k by which d i r e c t and i n d i r e c t impacts a re measured i s p o p u l a t i o n demography. However, d e t e r m i n i n g a p o p u l a t i o n ' s s t a t u s i s time consuming, expensive, and d i f f i c u l t . F r e q u e n t l y , p o p u l a t i o n s t a t u s i s unknown p r i o r t o opening an area f o r r e s o u r c e development, and p o p u l a t i o n s can undergo l a r g e d e c l i n e s b e f o r e i t i s d e m o n s t r a t i v e l y apparent t h a t d e c l i n e s a re o c c u r r i n g . Recovery i s slow, i f not i m p o s s i b l e . C o n s e r v a t i o n o f s p e c i e s l i k e t he g r i z z l y , which have low r e p r o d u c t i v e 114 p o t e n t i a l , w i l l depend on our a b i l i t y t o as s e s s the occurrence and probable e x t e n t o f p o p u l a t i o n d e c l i n e s e a r l y , and t o modify human a c t i v i t i e s i f necessary. P r e s e n t l y , a c t i v i t y parameters are of l i m i t e d u t i l i t y i n a s s e s s i n g i n d i r e c t impacts of human a c t i v i t i e s on bears. T h i s study i n d i c a t e s t h a t bears p r e f e r t o use d a y l i g h t , and a p p a r e n t l y w i l l c o n t i n u e t o do so i n areas where human a c t i v i t y i s p r e d i c t a b l e and l o c a l i z e d . The dense cover o f the low e l e v a t i o n p o r t i o n s o f the F l a t h e a d a l s o l i k e l y had a m i t i g a t i n g e f f e c t . However, n o c t u r n a l a c t i v i t y by bears may per m i t the e x p l o i t a t i o n o f h a b i t a t s u n a v a i l a b l e d u r i n g d a y l i g h t and hence, reduce some i n d i r e c t impacts o f human a c t i v i t i e s . M o d i f i c a t i o n s i n b e h a v i o r o f a p o p u l a t i o n a re not i n themselves i n d i c a t i o n s o f reduced e n e r g e t i c s t a t u s o r p o p u l a t i o n d e c l i n e . The s i m i l a r i t y i n a c t i v i t y budgets between g r i z z l i e s i n the F l a t h e a d and o t h e r p o p u l a t i o n s t h a t f o l l o w a n o c t u r n a l a c t i v i t y schedule would suggest l i t t l e d i f f e r e n c e i n the a b i l i t y o f bears t o e x p l o i t r e s o u r c e s i n d a y l i g h t o r darkness. However, such comparisons a r e confounded by d i f f e r e n c e s i n h a b i t a t q u a l i t y and predominate food t y p e s , and by a l a c k o f v i t a l i n f o r m a t i o n (e.g. age o f f i r s t r e p r o d u c t i o n , l i t t e r s i z e , i n t e r b i r t h i n t e r v a l s , p o p u l a t i o n d e n s i t y ) t h a t i n t e g r a t e s the animal w i t h i t s environment. Appendix 1. Data t o t a l s (sum of a c t i v e and i n a c t i v e bout d u r a t i o n s ) by bear, year, and season, i n decimal hours. Bear Age c l a s s , sex, and No. r e p r o d u c t i v e s t a t u s s o r i n g e a r l y summer b e r r v season 1984 46 subadult male 47 subadult male 48 subadult female 37.60 45.98 67.03 60.72 1985 25 a d u l t male — — 142.67 3 6 subadult female — 15.10 37.00 38 subadult female 46 subadult male 6.45 19.88 47 subadult male — 4.52 48 subadult female 80.82 49.99 8.72 1986 18 36 38 46 48 ad u l t female, y e a r l i n g s a d u l t female, C0YS a subadult female a d u l t male subadult female 4.13 43.87 41.48 21.90 17.95 10.42 24.25 Appendix 1. Continued. Bear Age c l a s s , sex, and No. r e p r o d u c t i v e s t a t u s s p r i n g 1987 25 a d u l t male 36 a d u l t female, y e a r l i n g s 38 a d u l t female, alone 45 a d u l t female, alone 46 a d u l t male 48 a d u l t female, alone 58 a d u l t female, alone 63 subadult male 64 subadult male 65 a d u l t male 67 subadult female 68 subadult female 69 subadult male 1988 25 a d u l t male b 27.40 36 a d u l t female, alone 118.93 38 a d u l t female, COYS 66.92 48 a d u l t female, alone 35.32 63 subadult male 83.60 65 a d u l t male 25.23 67 subadult female 53.88 68 subadult female 95.77 aCOYS = cubs-of-the-year. accompanied by 2-year-olds i n s p r i n g . e a r l y summer b e r r y season f a l l 60.65 135.67 151.32 38.93 125.75 31.38 106.68 121.72 146.15 90.85 44.80 38.82 150.47 93.45 140.65 52.43 93.37 19.23 201.53 167.25 100.28 100.83 123.12 62.57 53.87 57.28 85.55 50. 62 44.57 56.43 4.55 46.57 84 .73 68.03 52.60 197.48 128.15 3.02 98. 60 62.20

Cite

Citation Scheme:

    

Usage Statistics

Country Views Downloads
Germany 5 1
United States 3 0
China 3 0
Canada 1 0
Croatia 1 1
City Views Downloads
Unknown 7 2
Beijing 3 0
Mountain View 2 0
Ashburn 1 0

{[{ mDataHeader[type] }]} {[{ month[type] }]} {[{ tData[type] }]}

Share

Share to:

Comment

Related Items