khutzeymateen valley grizzly bear study : final report...grizzly bear – british columbia –...

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Ministry of ForestsResearch Program

KHUTZEYMATEEN VALLEYGRIZZLY BEAR STUDY

by

A.G. MacHutchonS. Himmer

C.A. Bryden

A cooperative project ofthe Ministry of Environment, Lands and Parks and the Ministry of Forests

Wildlife Branch Research BranchMinistry of Environment, Lands and Parks Ministry of Forests

Victoria, B.C. Victoria, B.C.

Fish and Wildlife Branch Prince Rupert Forest RegionMinistry of Environment, Lands and Parks Ministry of Forests

Smithers, B.C. Smithers, B.C.

Integrated Resources Branch North Coast Forest DistrictMinistry of Forests Ministry of Forests

Victoria, B.C. Prince Rupert, B.C.

Wildlife Report No. R-25Wildlife Habitat Research Report No. 31

January 1993

This publication is Wildlife Report No. R-25, WildlifeBranch, Ministry of Environment, Lands and Parks

Wildlife Habitat Research Report No. 31, ResearchBranch, Ministry of Forests

A cooperative project of the Ministry of Environment,Lands and Parks and the Ministry of Forests

Copies of this report may be obtained, depending onsupply, from:

Research BranchMinistry of Forests31 Bastion SquareVictoria, B.C.

The contents of this report may not be cited, in whole orin part, without the approval of the Director, ResearchBranch, B.C. Ministry of Forests, Victoria, B.C.

Cover photo: Stefan Himmer

Canadian Cataloguing in Publication DataMacHutchon, Arthur Grant, 1959-

Khutzeymateen Valley grizzly bear study

(Wildlife report, ISSN 0829-7797; no R-25)(Wildlife habitat research report, ISSN 0825-2769;no. 31)

“A cooperative project of the Ministry ofEnvironment, Lands and Parks and the Ministry of Forests.”Includes bibliographical references: p.ISBN 0-7726-7400-0

1. Grizzly bear – British Columbia – KhutzeymateenRiver Valley – Habitat. 2. Grizzly bear – British Columbia – Khutzeymateen River Valley – Behaviour.3. Grizzly bear – British Columbia – Khutzeymateen River Valley – Feeding and feeds. I. Himmer, S.II. Bryden, Colleen A. III. British Columbia.Ministry of Environment, Lands and Parks IV.British Columbia. Ministry of Forests. V. Title.VI. Series: Wildlife report (Victoria, B.C.); no.R-35. VII. Series: Wildlife habitat research;WHR-31.

QL737.C27M32 1992 599.74’4460451 C93-092046-5

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ACKNOWLEDGEMENTS

Two people were instrumental in ensuring that the Khutzeymateen Valley Grizzly Bear Study happened.On the surface, Tony Hamilton, Ministry of Environment, Lands and Parks (MOELP), Victoria, wassupervisor and management committee member. In reality, he was the heart and soul of the entireKhutzeymateen project. Logistic support, field assistance, technical advice, editorial comment, computernerding, vision, friendship — he provided it all. Bill Jackson, Ministry of Forests (MOF) retiree, PrinceRupert, made sure the field research proceeded without major incident. With his endless bag of tricks he madeseemingly big problems small. Bill also had a large supply of humour, friendship, advice, and concern he waswilling to share.

John Nagy handled many of the study’s logistical nightmares, directed the first season of field research,and set up a data collection and analyses structure that made it easy for us to take over. He devotedtremendous energy to making sure the first year and a half was a success. Frances Backhouse worked longand hard hours throughout the second field season. Her commitment was greatly appreciated.

Personnel of the North Coast Forest District, Prince Rupert, were always on hand to assist us withaspects of the field research. Thanks to B. Couperous, C. Demings, M. Easy, R. Fowler, D. Geiger,M. Grainger, R. Kabool, P. Madeley, A. Moen, B. Myers, E. Nelson, P. Perkins, C. Salter, K. Sawchuk,B. Wager, J. Watts, A. Wheatley, T. Wisdeski, and B. Young. Special thanks to G. Adolph who made sure hisstaff and the district’s resources were always available, L. Karlsen who never seemed to tire of our continualrequests for budgetary assistance, and W. Lindenblatt who always seemed to find what we were looking for.T. Frazier, R. Sobel, and W. Thompson always had a nice dinner for us when the Coast Ranger or Poplar IIIwere in the vicinity.

D. Eastman, MOELP, Victoria, and B. Nyberg, MOF, Victoria, oversaw the grizzly bear study workinggroup and provided field assistance, technical advice, and editorial comment.

F. Bunnell, S. Herrero, B. McLellan, and J. Schoen took time out from their busy schedules to act as theResearch Advisory Committee. They reviewed the working plan, progress reports, and an earlier draft of thisreport and we thank them for their comments.

E. Lofroth, MOELP, Smithers, spent considerable time preparing bait for the first trapping period andhelped out in the field numerous times. M. Eng, MOELP/MOF, Victoria, patiently guided us through the GISlabyrinth in addition to helping out in the field. B. Bonnor, R. Mark, W. Jones, and others at the InventoryBranch, MOF, Victoria, spent long hours grappling with the various GIS themes. R. McCann, R. Page, andW. Bergerud, MOF, Victoria, provided helpful advice on statistical analyses and tests for habitat selection.R. McCann was generous with his computer programs. A. Banner and S. Thomson, MOF, Smithers, werealways available to answer questions about vegetation ecology and provide assistance with vegetation dataanalyses.

Vancouver Island Helicopters, Prince Rupert, provided safe and reliable logistic support. R. Schur wasthe helicopter pilot for all three trapping periods. His fine skill as a pilot was certainly appreciated and he wasa pleasure to have at camp. We also thank the pilots and dispatch personnel of Trans Provincial Airlines,Prince Rupert, for their help with aerial telemetry and transportation.

W. McCrory, C. Russell, E. Mallam, T. Ellison, D. Freeze, J. Turner, S. Turner, and A. Dorst provided uswith a wealth of information gathered during their work in the watershed and we will fondly rememberdinners aboard the Ocean Light.

The Research and Development Section, MOELP, Victoria, made us feel at home during data analysesand write-up. L. Stanlake, G. Harcombe, L. Foxhall, and D. Cooper, MOELP, Victoria, helped edit, type, andformat the progress reports.

T. Boothman, MOF, Smithers, managed to secure some of the important field equipment. G. Allen,H. Langille, and other members of the electronics section, MOF, Smithers, made sure we were always in

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constant communication with the rest of the world. Fishermen’s Co-op and McMillan Fisheries, PrinceRupert, supplied most of the bait. Various people at the Department of Fisheries and Oceans, Prince Rupert,provided salmon escapement information.

Finally, we would like to thank the following individuals who voluntarily chose to expose themselves tothe climatic, geographic and biotic hardships of the Khutzeymateen Valley: R. Archibald, K. Atkinson,V. Banci, B. Beasley, P. Belliveau, L. Bonner, K. Bowen, S. Chatwin, C. Chestnut, D. Doyle, A. Edie, B. Fuhr,G. Harrison, S. Harrison, L. Hartman, A. Hetherington, K. Himmer, M. Hobson, R. Hoffos, R. Houtman,D. McGillis, B. McLellan, T. Manning, D. Miller, A. Rahme, G. Schultze, J. Shatford, T. Smith, C. Stewart,G. Taylor, L. Turney, D. Wellwood, D.W. Wellwood, and S. Wilson.

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TABLE OF CONTENTS

ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1 BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3 STUDY AREA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

4 METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4.1 Capture and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.2 Seasonal Food Habits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.2.1 Diet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.2.2 Seasons of activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.3 Population Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.3.1 Incidental observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.3.2 Remote cameras . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.4 Home Ranges and Movements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.4.1 Telemetry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.4.2 Home range analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.4.3 Spatial distribution of activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.5 Habitat Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104.5.1 Data analyses and biases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104.5.2 Habitat selection and preference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124.5.3 Prominence value of food plants within habitats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.5.4 Evaluating working plan hypotheses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.5.5 Use of forest cover units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.5.6 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.5.7 Denning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.5.8 Habitat value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.6 Supplementary Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.6.1 Other wildlife . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.6.2 Human use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5 RESULTS AND DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1 Capture and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175.1.1 Morphometrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2 Seasonal Food Habits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185.2.1 Diet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185.2.2 Seasons of activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

5.3 Population Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255.3.1 Number of grizzly bears using the study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255.3.2 Grizzly bear density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325.3.3 Reproduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345.3.4 Mortality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35


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5.4 Home Ranges and Movements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355.4.1 Movements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355.4.2 Home ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395.4.3 Spatial distribution of activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5.5 Habitat Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445.5.1 General habitat use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455.5.2 Habitat selection and preference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.5.3 Prominence value of food plants within habitats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595.5.4 Evaluation of working plan hypotheses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615.5.5 Use of forest cover units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625.5.6 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 635.5.7 Denning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655.5.8 Habitat value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 695.5.9 Habitat values assigned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

5.6 Supplementary Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 745.6.1 Other wildlife . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 745.6.2 Human use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

5.7 Management Implications of Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 775.7.1 Direct human impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 775.7.2 Habitat sensitivity to forest development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

6 LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

APPENDICES

1 Grizzly bear capture data for the Khutzeymateen study area, 1989–1991 . . . . . . . . . . . . . . . . . 87

2 Black bear and wolf capture data for the Khutzeymateen study area, 1989–1991 . . . . . . . . . . 89

3 Summary of all photos (except test photos) taken at remote camera sites in the Khutzeymateenwatershed, 31 July–29 September, 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

4 Summary of grizzly bear detections at the remote camera sites in the Khutzeymateen watershed,31 July–29 September, 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

5 Descriptions of known or suspected grizzly bear mortalities, 1989–1991 . . . . . . . . . . . . . . . . . 92

6 Specific movement patterns and home ranges of radio-collared grizzly bears, 1989–1991 . . . 93

7 Seasonal breakdown by ecosystem unit for aerial and ground locations of radio-collared grizzlybears in the Khutzeymateen study area, 1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

8 Frequency of use of Bear Habitat Units (BHUs) by radio-collared grizzly bears in theKhutzeymateen study area, 1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

9 Measurements of dens visited during the Khutzeymateen Grizzly Bear Study . . . . . . . . . . . . . 104

10 Birds identified in the Khutzeymateen study area and Khutzeymateen Inlet, 1989–1991 . . . . . 104

11 Mammal species or their sign identified in the Khutzeymateen study area and KhutzeymateenInlet, 1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105


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TABLES

1 Biogeoclimatic zones, subzones, and ecosystem units mapped for the Khutzeymateen watershedand Larch and Cedar creeks by Clement (1990) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Area breakdown of the Khutzeymateen study area by biogeoclimatic zone and physiographicgrouping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3 Start and end dates for telemetry during the Khutzeymateen Valley Grizzly Bear Study,1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4 Bear Habitat Units (BHUs) for the Khutzeymateen study area and their derivation from theecosystem units defined by Clement (1990) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5 Bear Habitat Types (BHTs) for the Khutzeymateen study area and their derivation from BearHabitat Units (BHUs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6 Summary of grizzly and black bear captures in the Khutzeymateen study area, 1989–1991 . . 18

7 Summary of grizzly and black bear capture success in the Khutzeymateen study area, 1989–1991 18

8 Mean spring weights of grizzly and black bears captured in the Khutzeymateen study area,1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

9 Food items known to be consumed by grizzly bears in the Khutzeymateen study area . . . . . . 20

10 Salmon escapement estimates for the Khutzeymateen River, 1989–1991 . . . . . . . . . . . . . . . . . . 21

11 Incidental observations of grizzly bears during the Khutzeymateen Valley Grizzly Bear Study,1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

12 Summary of photos (excluding test photos) taken at remote camera sites in the Khutzeymateenwatershed, 31 July–29 September 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

13 Number of bear detections and camera-days per detection at remote camera sites in theKhutzeymateen watershed, 31 July–29 September 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

14 Camera-hours per bear detection at remote cameras during different time periods . . . . . . . . . . 30

15 Minimum number of different grizzly bears using three areas of seasonal concentration in theKhutzeymateen study area, 1990 and 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

16 Minimum number of different grizzly bears identified each year in the Khutzeymateen studyarea, 1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

17 Number of different grizzly bears known to have used the Khutzeymateen study area during theperiod 1989–1991 and potentially still using the study area in 1991 . . . . . . . . . . . . . . . . . . . . . 32

18 Minimum number of grizzly bears present in the Khutzeymateen study area in 1991 for each ofthe three active seasons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

19 Estimated seasonal densities of grizzly bears using the Khutzeymateen study area and watershedin 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

20 Known and inferred reproductive history of female grizzly bears in the Khutzeymateen studyarea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

21 Days spent in the Exchamsiks River valley by radio-collared female grizzly bears in 1990and 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

22 Estimates of 100% minimum convex polygon (MCP) home range size for adult female grizzlybears in the Khutzeymateen study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40


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23 Estimates of 100% minimum convex polygon (MCP) home range size for subadult male grizzlybears in the Khutzeymateen study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

24 Estimates of 100% minimum convex polygon (MCP) home range size for adult male grizzlybears in the Khutzeymateen study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

25 Summary of data types collected during the Khutzeymateen Valley Grizzly Bear Study,1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

26 Number of aerial and ground telemetry locations of radio-collared grizzly bears obtained in1989–1991 and number that resulted in a site investigation (Site) or were typed remotely(Remote) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

27 Primary activity recorded for ground and aerial telemetry locations in the study area, 1989–1991 46

28 Seasonal breakdown by Bear Habitat Unit (BHU) for aerial and ground locations of radio-collared grizzly bears in the Khutzeymateen study area, 1989–1991 . . . . . . . . . . . . . . . . . . . . . 47

29 Seasonal breakdown by Bear Habitat Unit (BHU) for feeding and bedding activities of radio-collared grizzly bears within the Khutzeymateen study area, 1989–1991 . . . . . . . . . . . . . . . . . 48

30 Manly’s beta values for each radio-collared bear by Bear Habitat Type (BHT) . . . . . . . . . . . . 56

31 Manly’s beta values for each radio-collared bear by Bear Habitat Type (BHT) . . . . . . . . . . . . 57

32 Comparisons between ranks of selection of BHTs using the Friedman test (Conover 1980) . . 59

33 Prominence values of frequently used grizzly bear food plants for Bear Habitat Types (BHTs) inthe Khutzeymateen study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

34 Distribution of sampled mark trees in the Khutzeymateen study area, 1989–1991 . . . . . . . . . . 65

35 Summary of radio-collared grizzly bear den information for the Khutzeymateen study area . . 68

36 Seasonal type values assigned to Bear Habitat Units (BHUs) in the Khutzeymateen study area 73

37 Seasonal type values assigned to Bear Habitat Types (BHTs) in the Khutzeymateen study area 74

38 Summary of human use of the Khutzeymateen study area and adjacent Khutzeymateen Inlet,1990 and 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

FIGURES

1 The Khutzeymateen study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Location and distribution of biogeoclimatic zones and subzones in the Khutzeymateenstudy area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Hourly distribution of telemetry locations obtained during the Khutzeymateen study . . . . . . . . 11

4 Use of food types during 1989 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22



7 Use of different food groups by season, 1989–1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

8 Location of remote camera sites in the Khutzeymateen watershed . . . . . . . . . . . . . . . . . . . . . . . 28

9 River valleys surrounding the Khutzeymateen study area and passes providing access to thesevalleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36


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10 Areas of season 1 activity in the Khutzeymateen study area as indicated by aerial telemetrylocations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41



13 Distribution of seasonal elevation and horizontal distance to a class I stream for all aeriallocations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

14 Selection shown for Bear Habitat Units (BHUs) by individual grizzly bears, illustrated as percentuse minus percent available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

15 Bear Habitat Type (BHT) availability in the Khutzeymateen study area including and excludingthe Alpine Tundra zone, and the percent use of BHTs for aerial and ground locations and aeriallocations alone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

16 Seasonal use and availability of Bear Habitat Types (BHTs) in the Khutzeymateen study area forpooled aerial and ground locations, including and excluding the Alpine Tundra zone . . . . . . . 54

17 Seasonal use of Bear Habitat Types (BHTs) for feeding and bedding . . . . . . . . . . . . . . . . . . . . 55

18 Chesson’s electivity indices for individual grizzly bears by Bear Habitat Type (BHT) . . . . . . . 58

19 Use and availability of Inventory Type Groups (ITGs) for pooled samples of aerial and groundlocations and aerial locations only, including and excluding the non-forested class . . . . . . . . . 62

20 Use and availability of forest cover age classes for pooled samples of aerial and ground locationsand aerial locations only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

21 Location of mark trees found in the Khutzeymateen study area . . . . . . . . . . . . . . . . . . . . . . . . . 64

22 Diameter at breast height (DBH) and age distribution of measured mark trees . . . . . . . . . . . . . 66

23 Den locations of radio-collared grizzly bears in the Khutzeymateen study area and adjacentMouse Creek watershed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

24 Black bear observations recorded during helicopter surveys in May 1989 . . . . . . . . . . . . . . . . . 76

A6.1 Minimum annual (1989) home range polygons for adult females GF18 and GF24 . . . . . . . . 94

A6.2 Minimum annual home range polygons for adult female GF26 . . . . . . . . . . . . . . . . . . . . . . . 94

A6.3 Seasonal home range polygons for adult female GF34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

A6.4 Minimum annual home range polygons for adult female GF40 . . . . . . . . . . . . . . . . . . . . . . . 95

A6.5 Minimum annual home range polygons for adult females GF41 and GF43 . . . . . . . . . . . . . . 96

A6.6 Minimum annual (1991) home range polygons for adult females GF54 and GF56 . . . . . . . . 97

A6.7 Spring and early summer home range polygon for adult male GM47 . . . . . . . . . . . . . . . . . . 98

A6.8 Minimum annual home range polygons for subadult males GM02, GM22, and GM36 . . . . 99

SEQ 4850 JOB KHUTZ-051-022 PAGE-0001 PAGE 1 REVISED 21MAY00 AT 18:04 BY BC DEPTH: 60.01 PICAS WIDTH 43.06 PICAS COLOR LEVEL 1

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EXECUTIVE SUMMARY

The Khutzeymateen Valley Grizzly Bear Study was conducted between 1989 and 1991 as a componentof the Khutzeymateen Project. A wide range of information on grizzly bears (Ursus arctos) in theKhutzeymateen study area was collected to estimate population density and determine habitat value. Meetingthese objectives was important for evaluating the impact of proposed land use scenarios on grizzly bears andtheir habitat.

Grizzly bears were radio-collared and monitored over the 3 years of study. Basic life history informationon movements, food habits, reproduction, mortality, and denning was collected. Three main seasons ofactivity were identified. Trapping, incidental observations, detection at remote camera sites, and aerialsurveys were methods used to determine population characteristics. Aerial and ground telemetry locationswere used to determine habitat use and evaluate what habitats were selected and preferred by grizzly bears ona seasonal basis. Habitat use was examined at two levels of resolution: Bear Habitat Units (BHUs) and BearHabitat Types (BHTs). Both BHUs and BHTs were seasonally rated from very high to nil for grizzly bearsbased on the above analyses, as well as: the prominence values of major grizzly bear foods within habitats; aqualitative assessment of relative habitat capability in adjacent watersheds; and a qualitative interpretation ofpatch use.

Sixty-four grizzly bears (including young) that used the Khutzeymateen study area were identifiedduring the 3 years of study. However, nine of these bears were known or suspected to have died by 1991.Fifty-one grizzly bears were identified during 1991 and within each season 30–40 different bears wereidentified. Based on these numbers, seasonal density estimates were determined, and ranged from 4.7 to 14.8km2 per bear.

Grizzly bears using the Khutzeymateen study area spent most of their active period on lower slopes orvalley bottoms, particularly the valley bottoms of the lower Khutzeymateen and Kateen rivers and lowerCarm Creek. During all seasons, grizzly bears actively selected habitats for feeding and bedding and withineach season they preferred certain habitats. Generally, the preferred and most heavily used habitats in allseasons were those on lower slopes and valley bottoms. These included both non-forested and forestedhabitats. Forested habitats such as floodplain old growth and skunk cabbage old growth were consistentlypreferred in all seasons, as were non-forested wetlands and estuaries. Sidehill old growth with high moistureand nutrient regimes and a diverse, abundant understory was used in all seasons and was preferred for feedingover drier sidehill old growth. The lower slopes of both types of sidehill old growth were frequently used forbedding, particularly when adjacent to well-used feeding areas.

The productive lower slopes and valley bottoms in the Khutzeymateen study area are some of the bestbear habitat. They are also among the best timber growing sites. This puts conventional timber extraction andthe maintenance of grizzly bear numbers and habitat in direct conflict. There is concern that conventionaltimber extraction would have a major effect on the capability of the Khutzeymateen study area to support andsustain the current grizzly bear population.

1 BACKGROUND

The Khutzeymateen Valley Grizzly Bear Study is a component of the Khutzeymateen Project, a 3-yearcooperative study designed to provide information necessary to develop a plan for future use of theKhutzeymateen watershed in north coastal British Columbia. An initial working plan was prepared (Hamiltonand Nagy 1990) and three seasons of field study were completed in 1989, 1990, and 1991. The results of the1989 field season and working plan for year 2 were presented in Nagy and MacHutchon (1991). The results ofthe 1990 field season and working plan for year 3 were reported in MacHutchon and Himmer (1992). Thisreport summarizes the results from all three seasons of research.


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2 OBJECTIVES

The objectives of the Khutzeymateen Valley Grizzly Bear Study as stated in the working plan (Hamiltonand Nagy 1990) were:

1. to test current concepts of seasonal habitat use and selection by coastal grizzly bears and, if necessary,to develop a revised conceptual model applicable to the Khutzeymateen ecosystem;

2. to identify, map, and determine the abundance of habitat units and to assess their relative importanceto grizzly bears using the Khutzeymateen ecosystem;

3. to identify and quantify the available resources (e.g., food, cover) within these habitat units and toassess their relative importance to grizzly bears using the Khutzeymateen ecosystem;

4. to estimate the population density of grizzly bears resident in the Khutzeymateen ecosystem, and toestimate the total number of bears using the watershed; and

5. to predict and assess the impacts of proposed land use scenarios for the Khutzeymateen ecosystem ongrizzly bears and their habitat.

At the time of working plan development, current concepts of seasonal habitat use and selection bycoastal grizzly bears were based on information from the Coastal Grizzly Project (Archibald and Hamilton1985; Archibald et al. 1985; Hamilton and Archibald 1985, 1986; Hamilton et al. 1986; Hamilton 1987,1988). Begun in 1982 and still in progress, the project was designed to determine the effects of logging andsilviculture on grizzly bears throughout coastal British Columbia (Hamilton and Nagy 1990). This documentrepresents the culmination of work conducted to develop a conceptual model of habitat use and selectionapplicable to the Khutzeymateen ecosystem. Objectives 2 and 3 are addressed in Section 5.5; objective 4 isaddressed in Section 5.3; objective 5 is partially addressed in Section 5.7 and more fully covered in Mitchelland Hamilton.1

3 STUDY AREA

The study area includes the drainages of the Khutzeymateen River and Larch and Cedar creeks, coveringapproximately 443 km2 (Figure 1). It is located 45 km northeast of Prince Rupert at the head of Khutzeyma-teen Inlet. The majority of intensive field research on grizzly bears was carried out in the Khutzeymateenwatershed portion of the study area because it was difficult to access Larch and Cedar creeks on the groundand there were no radio-collared bear locations beyond their estuaries.

The study area is in the Western Kitimat Ranges of the Coast Mountains. Topography is rugged, withelevations ranging from sea level to over 2100 m. Major terrain units include: a large estuary, level fluvialareas (floodplain), some upslope units with very shallow soils over bedrock, numerous avalanche tracks,organic bogs, and several colluvial and alluvial fans. Soils are typically Humo-Ferric Podzols and Ferro-Humic Podzols in mid-slope positions, but Typic Folisols are also common on shallow-to-bedrock sites(Baender 1976).

The climate is wet, mild, and oceanic (Banner and Yole 1986). Temperatures vary little throughout theyear; the mean annual temperature is 7°C, the mean temperature of the warmest month is 16.1°C, and themean temperature of the coldest month is −3.1°C. Mean annual precipitation is 304 cm, of which approx-imately 12% falls as snow (mean annual snowfall of 356 cm) (Banner and Yole 1986). Although winterconditions are usually not extreme, outflow winds can freeze upper Khutzeymateen Inlet.

1 Mitchell, A.S. and A.N. Hamilton. 1992. Khutzeymateen: Evaluation of Various Options. Min. For. and Min. Environ., Lands andParks. Victoria, B.C. Internal document.

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FIGURE 1. The Khutzeymateen study area. Note: Only Khutzeymateen River and Inlet, Kateen River, Exchamsiks River, Carm Creek,Mouse Creek, Larch Creek and Cedar Creek are official Geological Survey of Canada place names.

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Three biogeoclimatic zones are represented in the watershed: the Coastal Western Hemlock (CWH) zone(very wet maritime [vm] and wet maritime [wm] subzones); the Mountain Hemlock (MH) zone (moistmaritime [mm] and moist maritime parkland [mmp] subzones); and the Alpine Tundra (AT) zone (Figure The zonal plant association (Pojar et al. 1987) is Tsuga heterophylla (western hemlock) — Abies amabilis(amabilis fir) — Thuja plicata (western redcedar) — Vaccinium spp. (blueberry, huckleberry species) Blechnum spicant (deer fern) — Rhytidiadelphus loreus (lanky moss) — Hylocomium splendens (step moss).In 1989, a vegetation inventory program was conducted in the Khutzeymateen study area to map biogeo-climatic and ecosystem units (Clement 1990) (Table 1). Clement (1990) mapped 116 ecosystem units. Thestudy area was mapped at 1:20 000 and the potentially operable area for conventional forestry, covering thevalley bottom and lower slopes, was mapped at 1:10 000 (Clement 1990). Habitat polygons were mapped single ecosystem units, or composites of two or three ecosystem units. Table 2 is an area breakdown of study area by biogeoclimatic zone and major physiographic grouping.

The fisheries resource of the Khutzeymateen has a commercial value estimated as high as $5 millionannually (Jantz 1984). Net wholesale contribution to the economy is $1.58 million per annum.2 From 1980 1988, Khutzeymateen River escapements averaged 385 chinook (Onchorhyncus tshawytscha), 4080 coho(O. kisutch), 7610 chum (O. keta), and 46 400 pink (O. gorbuscha) (Jantz et al. 1988). A few steelhead(O. gairdneri) also spawn in the Khutzeymateen River. Chinook generally arrive in late July, start spawningin mid-August, and end by mid-September. Coho arrive in late August, begin spawning in late October, andend by early December. There are generally two runs of chum salmon. The first arrives in mid-July, startsspawning in late July, and ends by mid-August. The second run of chum arrives in mid-August, startsspawning in late August, and ends in late September. Pink salmon arrive in mid-July, start spawning in early

FIGURE 2. The location and distribution of biogeoclimatic zones and subzones in theKhutzeymateen study area.

2 Kremer, E. 1985. Khutzeymateen River conceptual development plan. Dep. Fish. Oceans, Prince Rupert, B.C. Letter.

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CWH vm ES Estuary n/a n/a 2–3CWH, MH vm, wm, mm NW Non-forested wetland n/a n/a 2–3CWH, MH vm, wm, mm AV Avalanche track n/a n/a 1–3CWH, MH vm, wm, mm RO Rock outcrop n/a n/a 1CWH, MH vm, wm, mm OW Open water n/a n/a n/a

MH mm MM Mountain hemlock—moss n/a n/a 3–7MH mm HF Hellebore—fern n/a n/a 1–7MH mm SS Subalpine scrub n/a n/a 3—7MH mm FW Forested wetland n/a n/a 7MH mmp PA Parkland n/a n/a 1–2AT AT Alpine tundra n/a n/a 1–2

mmHF

Hellebore—fernn/an/a1–7

MH mm SS Subalpine scrub n/a n/a 3—7MH mm FW Forested wetland n/a n/a 7MH mmp PA Parkland n/a n/a 1–2AT AT Alpine tundra n/a n/a 1–2AT OW Open water n/a n/a n/a

a Zone: CWH=Coastal Western Hemlock; MH=Mountain Hemlock; AT=Alpine Tundra.b Subzone: vm=very wet maritime; wm=wet maritime; mm=moist maritime; mmp=moist maritime parkland.c Successional stages: 1=Non-vegetated; 2=Herb; 3=Shrub; 4=Pole-sapling; 5=Young forest; 6=Mature forest; 7=Old growth.

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August, and end by mid-September (Jantz et al. 1988). Salmon habitat inventories were undertaken by theDepartment of Fisheries and Oceans (Karanka 1986, 1990).

Administratively, the study area is within Management Unit 6-14 of Ministry of Environment, Lands andParks Region 6 and the North Coast Forest District of the Ministry of Forests Prince Rupert Forest Region.There are three small Indian reserves (IR 38, 39, and 49) in the Khutzeymateen watershed. An archaeologicalstudy of the watershed was conducted by the Ministry of Municipal Affairs, Recreation and Culture, cooperation with the Port Simpson Indian Band (Eldridge 1989; Eldridge et al. 1990). Historic structureswere located on the north shore of the inlet near the Khutzeymateen estuary and IR 49 along the lowerKhutzeymateen River. Both sites were thought to be Native fishing camps (Eldridge et al. 1990).

The only significant logging in the Khutzeymateen watershed occurred in 1950, when a small stand timber adjacent to the estuary was removed by Columbia Cellulose Ltd. (Karanka 1986), and in 1956 whenIR 49 was logged (Eldridge et al. 1990). Considerable volumes have been removed from Khutzeymateen Inletby ‘‘A-frame’’ operators in the 1950s and 1960s (Sullivan et al. 1986) and by helicopter in the early 1980s,under a major Timber Sale Licence to Silver Grizzly Ltd.

TABLE 1. Biogeoclimatic zones, subzones, and ecosystem units mapped for the Khutzeymateen watershedand Larch and Cedar creeks by Clement (1990)

Ecosystem unit

Biogeoclimatic Unit Major vegetation Seral General vegetation of Success.Zonea Subzonesb label association association seral association stages

CWH vm CM Cedar—moss n/a n/a 6—7CWH wm HM Hemlock—moss n/a n/a 3–7CWH vm, wm BM Blueberry—moss n/a n/a 3–7CWH vm, wm FF Fern—foamflower n/a n/a 5–7CWH vm, wm DC Devil’s club n/a n/a 1–7CWH vm, wm FD Floodplain devil’s club FD(1) Alder—willow—Rhacomitrium—riverbar 1–5CWH FD(2) Alder—salmonberry 3–5CWH FD(3) Alder—elderberry 3–5CWH FD(5) Salmonberry—red-osier dogwood 3–6CWH FD(6) Cottonwood—alder—salmonberry 4–6CWH FD(8) Cottonwood—spruce—salmonberry—devil’s club 3–7CWH FD(9) Cottonwood—alder—stink currant 3–6CWH vm, wm SC Skunk cabbage n/a n/a 3–7CWH vm ES Estuary n/a n/a 2–3

CWH, MH vm, wm, mm NW Non-forested wetland n/a n/a 2–3CWH, MH vm, wm, mm AV Avalanche track n/a n/a 1–3CWH, MH vm, wm, mm RO Rock outcrop n/a n/a 1CWH, MH vm, wm, mm OW Open water n/a n/a n/a

MH mm MM Mountain hemlock—moss n/a n/a 3–7MH mm HF Hellebore—fern n/a n/a 1–7MH mm SS Subalpine scrub n/a n/a 3—7MH mm FW Forested wetland n/a n/a 7MH mmp PA Parkland n/a n/a 1–2


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The Khutzeymateen watershed is the core of a grizzly bear kill-free zone (Hamilton and Nagy 1990).There has been no legal hunting of grizzly bears in this area since 1984. The kill-free zone is 3850 km2 in sizeand was intended to support a grizzly bear population of at least minimum viable size.3

TABLE 2. Area breakdown of the Khutzeymateen study area by biogeoclimatic zone and physiographicgrouping

Zonea Physiographic grouping Area (ha) Percent

AT Alpine 20 757 46.9MH Mature to old-growth forest 4 038 9.1MH Young seral forest 393 0.9MH Subalpine scrub 1 022 2.3MH Wetland 86 0.2MH Parkland 1 601 3.6MH Avalanche tracks 3 715 8.4MH Open water 11 0.0MH Rock 1 229 2.8

CWH Sidehill mature to old-growth forest 6 832 15.4CWH Sidehill early to young seral forest 733 1.7CWH Floodplain mature to old-growth forest 393 0.9CWH Floodplain early to young seral forest 353 0.8CWH Estuary 75 0.2CWH Wetland 72 0.2CWH Avalanche tracks 1 754 4.0CWH Riverbar 82 0.2CWH Open water 539 1.2CWH Rock 587 1.3

Total 44 272 100.0

a Zone: AT=Alpine Tundra; MH=Mountain Hemlock; CWH=Coastal Western Hemlock.

4 METHODS

4.1 Capture and Handling

Trapping was conducted in the spring of each year of the study. Trap sites were established at over 35locations in the Khutzeymateen study area. Different combinations of trap sites were used from year to year.Trap sites were located in a general core area along the lower Khutzeymateen and lower Kateen rivers, lowerCarm Creek, and on the estuaries of the Khutzeymateen River and Cedar and Larch creeks in all years.Additional trap sites were located along the upper Khutzeymateen and upper Kateen rivers and Colleen,Cedar, and Larch creeks in 1989 and 1991, and in Coliseum and Grant creeks in 1989 (Nagy and MacHutchon1991). Trap sites were chosen that had a helicopter landing area and good visibility of the trap site andsurrounding area from the air and ground. Sightings of bears or evidence of recent bear activity were alsoimportant in the selection of trap sites.

In 1989, the main trapping period began on 29 April and continued until 21 May . Trapping continued onthe estuary at sites accessible by jetboat until 29 May and opportunistically during late summer and fall. In an

3 van Drimmelan, B. 1984. Grizzly Bear Management Plan for Skeena Region. B.C. Min. Environ., Fish and Wildlife Branch,Smithers, B.C. Unpubl. man.


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attempt to capture more female grizzly bears, the trapping period was begun later in 1990 and 1991. In 1990,trapping was conducted from 22 May to 5 June and in 1991 from 22 May to 9 June. Capture success wasmeasured as the number of bears captured per trap-night. A trap-night was one snare or one barrel trap set outovernight and checked the following day.

Bears were captured, immobilized, and handled using procedures described by Hamilton and Nagy(1990).

4.2 Seasonal Food Habits

4.2.1 Diet

Food items eaten by grizzly bears using the Khutzeymateen study area were determined fromfeeding sign at activity sites, scat analysis in the field and lab, and incidental observations of feeding.Each year, before bears began feeding on salmon, known-aged scats (


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Columbia, but with two main modifications. A microwave sensor, in addition to the infrared sensor and aconverter (Cygnus Technologies, Penticton, B.C.), were added to allow a 12-volt battery to power boththe camera and the sensors.

The areas selected for remote camera sites were in parts of the valley where travel corridors wererestricted by topography, and grizzly bear use was expected to be high. Unlike Mace et al. (1990) andF. Hovey (pers. comm.), bait was not used at camera sites. Sites were along well-used bear trails, usuallyin association with mark trees. The camera unit was mounted on the side of a tree 2–3 m from the groundand angled so that the focal point of the camera was 3–4 m away on the bear trail. Units were mountedso they did not face directly into the sun. Site disturbance was kept to a minimum. Colour print film (100or 200 ASA) was used and the camera automatically recorded time and date on the photos. Camerasunits were checked regularly and batteries and film replaced as necessary.

Negatives were printed and categorized, and individual bears identified. It was not always possibleto categorize lone bears; age and sex class could not always be determined with a high degree ofconfidence. Subadults and adults were distinguished according to relative size.

A ‘‘detection’’ was considered a single visit by a bear to a remote camera site. An individual bearcould be detected more than once at the same or a different site in a 24-hour period. Chi-squaregoodness-of-fit tests (Zar 1974) were used to test for significant differences in frequency of beardetections at night and during the day and in seasons 2 and 3. Chi-square two-way contingency tabletests (Zar 1974) were used to test for significant differences in detection frequency between grizzly andblack bears and lone grizzly bears and family groups, on a seasonal basis and at night and during the day.Dawn and dusk were defined for this study as 1-hour periods — a half hour on either side of sunrise andsunset (official times from Environment Canada), respectively. Two calculations of detection rate weremade: camera-hours per detection and camera-days per detection (one day=24 camera-hours).

4.4 Home Ranges and Movements

4.4.1 Telemetry

Adult and subadult grizzly bears of both sexes were fitted with colour-coded radio collars at thetime of capture (Telonics Ltd., Mesa, Ariz.). An insert made from fire hose was added to each radiocollar so that it would fall off when the insert rotted through. Radio collars were equipped with 5-seconddelay, pulse-reset devices so that general activity (moving, resting) could be inferred during aerial andground monitoring.

Table 3 summarizes the start and end dates for aerial and ground telemetry sessions during 1989–1991. Aerial telemetry surveys were conducted weekly, weather permitting (Nagy and MacHutchon1991). Locations were recorded on 1988 1:14 000 colour air photos or 1:50 000 NTS topographic mapsand transferred to 1:10 000 or 1:20 000 habitat/TRIM (Terrain Resource Information Management)maps. Universal Transverse Mercator (UTM) coordinates (to the nearest 5 m) and elevation (to thenearest 5 or 10 m) were recorded for all locations. Ground telemetry was modelled after a systemdescribed by Hamilton and Archibald (1986). Approximately 80 fixed telemetry stations were estab-lished at intervals of 100–150 m along the Khutzeymateen River, Kateen River, Carm Creek andKhutzeymateen Inlet. Approximately 4 km of trail was cut to access Carm Creek. A 1.5 m length ofconduit pipe was driven vertically into the ground or a log at each fixed station. A mobile telemetry pole,consisting of a 4-element antenna attached horizontally to the end of a 2 m aluminum pole could beinserted into the conduit pipe. The antenna could be rotated 360°. A compass, fitted into the handle of thealuminum pole, was used to take bearings. If a bear was beyond the range of the fixed telemetry stations,then a hand-held H-antenna (Telonics Ltd., Mesa, Ariz.) or a hand-held 3-element Yagi antenna (LotekLtd., Aurora, Ont.) was used to obtain bearings from temporary stations.

Bearings were taken from at least three different stations to estimate a radio-collared bear’slocation. Bearings were plotted on air photos to indicate the approximate position of the bear for


9

subsequent ground investigation. If the location was not visited on the ground, a best estimate of thebear’s location (in UTM coordinates) was determined using the computer program POLYGON (Page1982) or by using the centre of error polygons plotted on air photos. Care was taken to use the centre ofair photos when plotting bearings, and only locations within 300 m of telemetry stations were deter-mined from air photos.

TABLE 3. Start and end dates for telemetry during the Khutzeymateen Valley Grizzly Bear Study, 1989–1991

Year Aerial telemetry Ground telemetry Den surveys

1989 29 May–24 October 8 June–17 October7 February, 1990

1990 24 April–31 October 25 April–18 October7 February, 1991

1991 8 April–1 October 28 April–23 September5 March, 1992

4.4.2 Home range analysis

All radio-collared bears were inaccessible to ground telemetry at various times in their activeseason, at which time they could only be located during aerial telemetry surveys. Telemetry surveys wereusually flown once a week. The combined aerial and ground location sample was not always a truerepresentation of a bear’s annual home range because the samples could be clumped in time and space.That is, a bear in the lower Khutzeymateen Valley was located more frequently than if it was in the upperKateen Valley and only accessible to aerial telemetry. Aerial locations alone would better representannual home range, but sample sizes were too small for non-parametric home range estimators such asharmonic mean measures (Dixon and Chapman 1980; Worton 1987; Ackerman et al. 1989; Boulangerand White 1990). Consequently, the 100% minimum convex polygon (MCP) home range estimate wasused (Mohr 1947). All locations (aerial, ground, capture, den, and incidental) were included. Outlierswere not removed (Hamilton et al. 1986) from the analysis because the low number of locations when abear was inaccessible made their certain identification impossible. Home range estimates were calcu-lated with the computer program HOME RANGE (Ackerman et al. 1989).

Multi-annual 100% MCP home ranges sizes for grizzly bears monitored for more than 1 year weredetermined using a Geographic Information System (GIS) overlay (PAMAP Graphics Ltd., Victoria,B.C.).

4.4.3 Spatial distribution of activity

Aerial location samples were insufficient to determine seasonal movements of individual radio-collared grizzly bears. However, pooling aerial locations for all radio-collared bears by season indicatedareas where activity was seasonally concentrated.

Null hypothesis 5 in the working plan for the Khutzeymateen Valley Grizzly Bear Study (Hamiltonand Nagy 1990) was: ‘‘Collared grizzly bears will use elevational strata in proportion to theiravailability.’’

A random number generator (SAS Institute Inc. 1985) was used to produce 1089 sets of UTMcoordinates that fell within the study area. These random points and a pooled sample of aerial locationsfor radio-collared grizzly bears were overlain on a TRIM base using PAMAP GIS to determineelevations for the random points and distance to class I streams for both samples. Elevations of aerial


10

locations were determined from TRIM maps in the field. Class I streams are defined as streams whereanadromous salmonids or moderate to high levels of resident sport fish are present (Coastal Fisheries/Forestry Guidelines 1988). Distance to class I stream was measured as a straight line point-to-pointhorizontal distance, regardless of slope; it is not the true ground distance. These distance measurementswere used to determine relative differences from random and for between-season comparisons.

Statistical comparisons between location distributions were done with chi-square contingency tabletests (Zar 1974).

4.5 Habitat Use

Aerial and ground telemetry location data were collected with the methods described in Section 4.4.1and Nagy and MacHutchon (1991). After a grizzly bear moved away from the area where it had been located,a ground investigation of the location was conducted. Considerable effort was taken to verify that an activitysite corresponded to the radio-collared bear’s location. Verification criteria included some or all of thefollowing: presence of grizzly bear hair; presence of appropriately sized grizzly bear tracks; proximity of theactivity to the location; bear sighting; relative age of the sign; presence of scats; and nature of the disturbance.When a researcher was confident that an activity site corresponded to a ground or aerial location, a siteinvestigation was carried out. The following information was collected for each site investigation: activity;proportion of vegetation in different strata; percent cover of all plant species present (using standardvegetation forms [Luttmerding et al. 1990]); cover value (Archibald et al. 1985); description of beds, marktrees and mark trails; food species consumed; and distance to and availability and abundance of salmon.Cover value was measured by two researchers. One researcher would crouch at the centre of activity and thesecond researcher would walk in each of the four cardinal directions. For each direction, the first researcherwould measure how far the second researcher walked before the lower half of his or her body disappearedfrom sight. The lower half of the body was considered to be the approximate shoulder height of a grizzly bear.Each site investigation was assigned to one of the ecosystem units described by Clement (1990) (Section 3.0).

Occasionally, aerial locations were inaccessible, were not visited, or were visited but turned upinsufficient sign to warrant a site investigation. These locations were assigned to an ecosystem unit based oninterpretation of site characteristics from the air at the time of location. Ground locations that were not visitedwere assigned to an ecosystem unit if researchers considered the telemetry location accurate and the locationwas within a simple mapped polygon (only one ecosystem unit mapped for the polygon), or the bear was seenduring telemetry.

Observations of radio-collared bears that did not occur during aerial or ground telemetry were occa-sionally used for subsequent site investigation. An incidental sighting often led to the discovery of an activitysite in an adjacent ecosystem unit.

In addition to site investigations done at telemetry locations or in association with an incidentalobservation, investigations were conducted at sites of activity found incidentally while researchers travelledthrough the watershed. However, the data from site investigations of unknown grizzly bear activity andincidental observations were not used in the evaluation of habitat use.

4.5.1 Data analyses and biases

The above methods of data collection have inherent biases that, to various degrees, diminish theireffectiveness in predicting real patterns of habitat use. To put the habitat use information in propercontext, the following discussion outlines biases and how they were addressed in the field and the dataanalyses. Assumptions necessary for evaluating the results are also discussed.

Ecosystem unit mapping was only done for the Khutzeymateen study area, which includes theKhutzeymateen watershed and Larch and Cedar creeks. Therefore, the analysis and discussion of habitat

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use is restricted to the Khutzeymateen study area, even though almost all the radio-collared bears wereactive outside the study area at various times over the 3 years of study (movements outside the study areaare discussed in Sections 5.4 and 5.5.8).

Restricted access to the study area and the limited size of the field crew ruled out collecting data atnight. All telemetry locations were obtained between 0800 hr and 2200 hr, with the majority between1000 hr and 2000 hr (Figure 3). Discussion of habitat use applies only to these daylight hours.

A major limitation on data collection was the lack of ground access to all parts of the study area,and the difficulty of movement within accessible areas. Effective ground telemetry and follow-up siteinvestigation of both ground and aerial locations was generally confined to the most accessible parts ofthe Khutzeymateen watershed: the lower Khutzeymateen River, lower Carm Creek, and lower KateenRiver. The relative accessibility of each of these areas, as well as the relative accessibility of the radio-collared bears, varied across seasons and across years. This limitation has been recognized in thediscussion of habitat use and in the assignment of habitat value.

A corollary to the lack of access was the unequal distribution of habitats within the study area and,therefore, their unequal representation within individual home ranges. To address this problem, habitatuse was evaluated for individual bears and the alternative habitat use strategies of bears occupyingdifferent parts of the study area were examined.

If an individual radio-collared bear concentrated its activity in inaccessible parts of the study area,then the majority of its locations had to be typed from the air. A problem with this was the difficulty indifferentiating between ecosystem units with similar forest canopies, and in locating precisely anindividual within a mosaic of small ecosystem units. In addition, the activity of the bear could rarely be

FIGURE 3. Hourly distribution of telemetry locations obtained during the Khutzeymateen study (n=600).


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discerned. As many aerial locations as possible were visited on the ground, and for all others it wasassumed that the habitat designation was accurate at least at the Bear Habitat Unit level (Figure 3).

Ground telemetry was most precise and accurate when radio-collared bears were close to telemetrystations and there was, therefore, a greater probability of finding and verifying these locations. Close-range telemetry was possible in nearly all accessible areas of the valley because of the narrow floodplainand proximity of most areas to watercourses or trails. However, it was not possible to get reliablelocations of grizzly bears in some areas that were less accessible or had topographical features thatconsistently interfered with the accuracy of the telemetry. This affected the data because less was knownabout grizzly bear activity in these areas than in areas of more ‘‘reliable’’ telemetry. This bias may haveaffected the precision of habitat selection for individual bears, but it is believed not to have adverselyaffected the assignment of habitat type value (defined in Section 4.5.8). Even if a precise location wasnot always obtained for a bear, its approximate position was usually known. That is, it was usuallyknown if a bear was on the valley bottom versus a side slope. This type of information could not bequantified, but it added qualitative support to the general pattern of habitat use.

There were too many ecosystem units (n=116) for meaningful summary of habitat use data;consequently, 30 Bear Habitat Units (BHUs) were created that brought together ecologically similarecosystem units (Table 4). All ecosystem units that were common to both subzones of the CWH zonewere put in the same BHU. These ecosystem units were considered to provide similar features for grizzlybears and no distinction had been made between the two subzones for silvicultural prescriptions(M. Grainger, pers. comm.). The other major groupings were for the Floodplain devil’s club (FD)ecosystem units, which were grouped according to successional stage into three BHUs.

In this report, general and individual habitat use patterns of grizzly bears are discussed at the BHUlevel. This discussion is followed by a more analytical evaluation of habitat use at the Bear Habitat Type(BHT) level (see below). Because of differences in potential harvesting and silvicultural methods withinindividual BHTs, BHUs were the level of habitat resolution used for forest development planning andevaluation in the Khutzeymateen.5 Habitat use for denning and marking are also summarized at the BHUlevel.

4.5.2 Habitat selection and preference

To conduct analytical tests of habitat selection and preference, Chesson (1983), Alldredge and Ratti(1986), Page6 and others recommend limiting the number of habitats considered to between 5 and 10.Alldredge and Ratti (1986) showed that as the number of resources increases, the Type II multiplecomparison error rates increase. For analytical evaluations of habitat selection and preference in thisstudy, the 30 BHUs were reduced to 10 Bear Habitat Types (BHTs) (Table 5). Ten was considered theminimum number for the results to be still biologically relevant to the questions being asked.

Habitat selection occurs when an animal actively chooses a habitat (Johnson 1980). Usage isconsidered selective if components are used disproportionately to their availability (Johnson 1980). Theunderlying assumption in comparisons of use and availability to determine habitat selection is that, in theabsence of selection, habitats would be used in proportion to their availability (McLellan 1986). Habitatpreference is the relative selection of one habitat over another when each is offered on an equal basis(Johnson 1980); preference is therefore relative to the choices available.


6 Page, R. 1986. Statistical analyses of habitat selection. B.C. Min. For. Victoria, B.C. Unpubl. notes.


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There are three problems associated with measuring and testing for selection and preference. First,conclusions about habitat use depend upon which habitats are considered available to an animal(Johnson 1980). ‘‘Bounding of availability’’ has been addressed by many researchers and is often anarbitrary decision. Johnson (1980) proposed that researchers consider selection as a hierarchy and that,by doing so, the components available would depend upon which level of selection was being examined.Johnson (1980) considered the highest level selection by an animal to be the selection of a physical orgeographic range. Within that range the second level of selection determines the home range. The thirdlevel is the selection of habitats within the home range. Once an animal has selected a feeding habitat,then the fourth level of selection would be for the food types to use at a feeding site. Johnson’s (1980)hierarchical approach to selection has been supported for studies of grizzly bears (McLellan 1986).

TABLE 4. Bear Habitat Units (BHUs) for the Khutzeymateen study area and their derivation from theecosystem units defined by Clement (1990) (see Table 1)

Bear Habitat Unit (BHU) Ecosystem unit

Biogeoclimatic Area Unit Seral Success.cZonea Subzoneb Name Acronym (ha) label assoc. stages

CWH vm,wm Avalanche track AVA 1 754 AV n/a 2,3CWH vm,wm Blueberry — moss young seral BMY 104 BM n/a 3,4,5CWH vm,wm Blueberry — moss mature to old growth BMO 4 560 BM,FF n/a 6,7CWH vm,wm Devil’s club shrub DCS 506 DC n/a 3CWH vm,wm Devil’s club young seral DCY 123 DC n/a 4,5CWH vm,wm Devil’s club mature to old growth DCO 1 726 DC n/a 6,7CWH vm Cedar — moss mature to old growth CMO 237 CM n/a 6,7CWH wm Hemlock — moss mature to old growth HMO 309 HM n/a 6,7CWH vm,wm Skunk cabbage early to young seral SCY 63 SC n/a 3,4,5CWH vm,wm Skunk cabbage mature to old growth SCO 155 SC n/a 6,7CWH vm,wm Floodplain devil’s club shrub FDS 164 FD 2,3,5,8,9 3CWH vm,wm Floodplain devil’s club young seral FDY 126 FD 1,2,3,5,6,8 4,5CWH vm,wm Floodplain devil’s club mature seral FDM 40 FD 6,8,9 6,7CWH vm,wm Floodplain devil’s club old growth FDO 198 FD 5 6,7CWH vm Estuary EST 75 ES n/a n/aCWH vm,wm Riverbar RIB 82 FD 1 1,2CWH vm,wm Non-forested wetland NFW 72 NW n/a 2,3CWH vm,wm Open water OWA 539 OW n/a n/aCWH vm,wm Rock outcrop ROC 587 RO n/a 1,7MH mm Avalanche track AVM 3 715 AV n/a 2,3MH mm Mountain hemlock early to young seral MHY 393 MM,HF n/a 2,3,4,5MH mm Mountain hemlock mature to old growth MHO 3 912 MM,HF n/a 6,7MH mm Forested wetland FWE 126 FW n/a 7MH mm Subalpine scrub SSC 1 022 SS n/a 3,4,6,7MH mm Rock outcrop RCM 1 229 RO n/a 1MH mm Open water OWM 11 OW n/a n/aMH mm Non-forested wetland NFM 86 NW n/a 2MH mmp Parkland PAR 1 601 PA n/a n/aAT Alpine tundra ALP 20 662 AL n/a n/aAT Open water AOW 95 OW n/a n/a

a Zone: CWH=Coastal Western Hemlock; MH=Mountain Hemlock; AT=Alpine Tundra.b Subzone: vm=very wet maritime; wm=wet maritime; mm=moist maritime; mmp=moist maritime parkland.c Successional stages: 1=Non-vegetated; 2=Herb; 3=Shrub; 4=Pole-sapling; 5=Young forest; 6=Mature forest; 7=Old growth.


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However, some argue that the hierarchical order of selection for grizzly bears is different from thatoutlined by Johnson (1980) (A. Hamilton, pers. comm.; Page7). The important assumption neverthelessis that selection is hierarchical. This study does not attempt to examine the processes that led grizzlybears to use the Khutzeymateen watershed for some or all of their annual activity. Selection at this levelis influenced by a variety of factors, the sex and age class of the animal, learned behaviour, intraspecificcompetition, density-dependent pressures, and habitat quality and quantity. Similarly, the study does

TABLE 5. Bear Habitat Types (BHTs) for the Khutzeymateen study area and their derivation from BearHabitat Units (BHUs)

Biogeoclimatic Bear Habitat Type (BHT) AreaZonea Subzoneb BHU Name Acronym (ha) %

CWH vm,wm AVAMH mm AVM Avalanche track AVU 5 470 12.4

CWH vm,wm BMYCWH vm,wm BMOCWH vm CMOCWH wm HMO Sidehill mesic SMU 5 210 11.8

CWH vm,wm DCSCWH vm,wm DCYCWH vm,wm DCO Sidehill very moist SVU 2 355 5.3

CWH vm,wm SCYCWH vm,wm SCO Skunk cabbage SCU 218 0.5

CWH vm,wm RIBCWH vm,wm FDS Floodplain early seral FEU 246 0.6

CWH vm,wm FDYCWH vm,wm FDMCWH vm,wm FDO Floodplain young seral to old growth FOU 364 0.8

CWH vm ESTCWH vm,wm NFW Non-forested — sedge NFU 148 0.3

CWH vm,wm OWACWH vm,wm ROCMH mm OWMMH mm RCM Non-vegetated NVU 2 366 5.3

MH mm MHYMH mm MHOMH mm FWEMH mm SSCMH mm NFMMH mmp PAR Mountain hemlock MHU 7 139 16.1

AT ALPAT AOW Alpine ATU 20 757 46.9

a Zone: CWH=Coastal Western Hemlock; MH=Mountain Hemlock; AT=Alpine Tundra.b Subzone: vm=very wet maritime; wm=wet maritime; mm=moist maritime; mmp=moist maritime parkland.

7 Page, R. 1986. Statistical analyses of habitat selection. B.C. Min. For. Victoria, B.C. Unpubl. notes.


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not address the decisions grizzly bears make about the food types they will feed on once they haveselected a particular feeding habitat.

Habitat selection and preference were examined according to two availability scenarios: 1) eachbear was considered to have all habitats in the study area available to it (i.e., availability was equalbetween individuals); and 2) habitat availability was dictated by a bear’s home range (i.e., availabilitywas not equal between individuals). It was assumed that grizzly bears knew all the habitats in their homeranges, that the energetic costs of moving between habitats were minimal, and that the habitats were notdepleted during the study period. Therefore, grizzly bears were always in a habitat that they selected at aparticular time for a particular reason (McLellan 1986). It was further assumed that the distribution oflocations among habitats for each radio-collared bear reflected its habitat selection (McLellan 1986).

The second problem in testing for selection is that individual grizzly bears have different selectionstrategies as a result of factors such as intraspecific competition and learned behaviour (Chesson 1978;Thomas and Taylor 1990). Individual differences in the selection of BHUs and BHTs are discussed.

The third problem in testing for selection is that most analytical methods rarely find selection for acommon resource because the resource must not only be used more than it is available, but significantlymore (McLellan 1986). McLellan (1986) suggests that if a bear uses a resource, then it has made aselection. This is true, but habitat use data alone may suggest that one habitat was preferred more thananother when, in fact, there were more locations in the habitat simply because it was abundant. That is,grizzly bears could have greater preference for a less abundant habitat, which may not show up in usedata alone. Therefore, use data were compared against habitat availability and the relative abundance ofhabitats was considered when assigning type and patch value (see Section 4.5.8).

A three-stage approach for evaluating habitat selection and preference was used in this study. Thefirst stage examined the statistical difference between the frequency distributions of use and availabilityto determine whether habitat selection was occurring (Neu et al. 1974; McLellan 1986). The frequencyof use of BHTs was compared to the availability of BHTs within the study area for a pooled sample of allaerial and ground locations (n=643) and aerial locations alone (n=339). The frequency of use of BHTsby individual radio-collared bears was then compared with the availability of BHTs; first, in the bear’smulti-annual home range, and then in the study area. The null hypothesis tested in the first stage was:

H0: Usage of habitats occurs in proportion to availability.

For both pooled and individual location samples, observed frequencies across BHTs were comparedwith expected frequencies using a chi-square goodness-of-fit test (Neu et al. 1974; Byers et al. 1984). Inaddition, for individual radio-collared bears, Friedman’s test (Conover 1980; Alldredge and Ratti 1986,1992) was used to determine whether the ranks of the differences in use and availability were the samefor all BHTs.

The second stage evaluated relative habitat preference and was primarily descriptive, so no specifichypothesis was tested. The analytical approach used to measure preference was the selectivity indexdescribed by Chesson (1978, 1983) and originally developed by Manly (1974).

The third stage tested for differences in the selection of particular BHTs. The null hypothesis testedin this stage was:

H0: The relative selection for habitat i equals that for habitat j.

To test this hypothesis for the pooled location samples, 95% confidence limits were constructedaround the proportion of locations in each BHT, using the Bonferroni approach, and compared to theproportion available (Neu et al. 1974; Byers et al. 1984). For individual bears, if the Friedman testrejected the null hypothesis of no selection, then Fisher’s least significant difference (LSD) procedurewas used to determine which BHTs had different selection ranks (Conover 1980; Alldredge and Ratti1986, 1992).


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4.5.3 Prominence value of food plants within habitats

The computer program PC-VTAB (B.C. Ministry of Forests 1991a ) was used to calculate, byecological unit, mean percent cover and the percent presence of all plant species recorded in thevegetation plots done for the ecological mapping (Clement 1990). Prominence value is determined bymultiplying a species’ mean cover by the square root of its percent presence for each ecological unit(Banner et al. 1986). Prominence values were calculated for 20 species considered to be importantgrizzly bear foods in the Khutzeymateen. The species prominence values for each ecological unit werethen grouped by the appropriate BHT and averaged. Two BHTs were not included in this analysis: NVUwhich, by definition (i.e., non-vegetated), does not have any food plants; and ATU in which novegetation plots were done.

4.5.4 Evaluating working plan hypotheses

Four null hypotheses relating to habitat use by grizzly bears were outlined in the working plan forthe Khutzeymateen Valley Grizzly Bear Study (Hamilton and Nagy 1990). The hypotheses wereoriginally stated in terms of the habitat classification system developed for the Kimsquit Valley GrizzlyBear Study (Hamilton 1987). The null hypotheses are restated below in terms of the Bear Habitat Types(BHTs) developed for the Khutzeymateen study.

1. The Floodplain young seral to old-growth forest (FOU) and Skunk cabbage (SCU) BHTs areused by radio-collared grizzly bears in proportion to their occurrence within home rangeavailability.

2. Bedding, marking, and travel activity by radio-collared grizzly bears occur evenly throughouthabitat patches of the Sidehill mesic (SMU) and Sidehill very moist (SVU) BHTs.

3. The number of seasons of use of the Floodplain young seral to old-growth (FOU) BHT by radio-collared grizzly bears is not significantly different from the number of seasons of use for otherBHTs with commercial forest.

4. There are no significant differences in food value ranks among the commercial forested BHTs.

Data that support or oppose these null hypotheses will be evaluated after the discussion of habitatselection and habitat preference.

4.5.5 Use of forest cover units

Sample size limitations required that analysis of forest cover data be done at a relatively generallevel — Inventory Type Group (B.C. Ministry of Forests 1991b ). Twelve Inventory Type Groups (ITGs)were available in the study area. However, it was necessary to lump some ITGs together to improvesample sizes. Six ITGs (H — hemlock; HC — hemlock-cedar; HB — hemlock-true fir; HS — hemlock-spruce; S — spruce; SH — spruce-hemlock) and three lumped categories (cedar-dominated [C and CH];mixed conifer-deciduous [HDecid and SDecid]; deciduous [DDecid and CotDecid]) were used in theanalyses. In addition, units without an ITG (i.e., non-forested) were included in some analyses. Chi-square goodness-of-fit tests were used to determine if there was an overall difference in the use andavailability distributions among these units; and Bonferroni procedures (Byers et al. 1984) were used todetermine which units were used more than expected. Forest cover age class information was analyzedin the same manner. Age classes were lumped into three groups: age classes 1–4 (1–80 years old), 5–8(81–250 years old), and 9 (251+ years old).

4.5.6 Marking

There was no systematic search for mark trees or trails in the Khutzeymateen study area. Markingsign was recorded opportunistically in the course of site investigations and ground travel. Data collected


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at marking sites included: mark tree species, age, and diameter; scar dimensions; trail characteristics;habitat type; and an estimate of when the tree or trail was last used.

4.5.7 Denning

Surveys were flown in early February 1990 and 1991 and early March 1992 to locate radio-collaredgrizzly bears in their dens. Elevation, tree species composition, general terrain, and snow conditionswere noted at the time of location. Slope and aspect were taken from a TRIM base map using PAMAPGIS. A plastic hoop tied with flagging tape, and in some cases equipped with a radio transmitter, wasplaced on the top of a tree near the den location. Den sites were investigated in mid- to late spring.

4.5.8 Habitat value

All BHTs and BHUs were assigned a type and patch value. Type value was considered to be thevalue of a habitat for feeding, bedding, and travel activities, regardless of where the habitat occurred inthe study area (Hamilton and Nagy 1990; Hamilton and Bunnell8). Patch value was a modification to atype value, based on where the habitat was in relation to other habitats or geographic features. Patchvalues for BHUs are not explicitly outlined in this report. However, patch value modifications to BHUtype values were incorporated into the impact assessment of different forest development scenariosconducted by Mitchell and Hamilton.9

Watersheds around the Khutzeymateen study area were surveyed in September and October 1991 tosee how they compared to the Khutzeymateen in terms of these watersheds’ relative use by grizzly bearsin season 3 (see Section 5.4.1). In addition, the Exchamsiks River was floated from the headwaters to theSkeena River in late August to early September 1990. Subjective assessments of their relative capabilityto support grizzly bears in other seasons were also made.

4.6 Supplementary Information

4.6.1 Other wildlife

Information on wildlife other than grizzly bears was recorded opportunistically during the 3 yearsof the study. Additional data on the distribution of black bears and mountain goats were obtained duringfive helicopter surveys flown in the study area in May 1989 (Section 4.3).

4.6.2. Human use

The number of people and the duration and purpose of their stay in the study area were recorded in1990 and 1991.

5 RESULTS AND DISCUSSION

5.1 Capture and Handling

Grizzly and black bear captures in the Khutzeymateen study area from 1989 to 1991 are summarized inTable 6. Twenty grizzly bears were fitted with radio collars (9 adult females, 7 adult males, and 4 subadultmales, including one 2-year-old). The overall capture success for the 3 years was: 20 trap-nights per bear

8 Hamilton, A.N. and F.L. Bunnell. [1992]. Integrating coastal grizzly bears and forest management at the regional, watershed, stand,and microsite levels. Int. Conf. Bear Res. and Manage. 9:000-000. In preparation.



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(black and grizzly); 38 trap-nights per grizzly bear; and 42 trap-nights per black bear (Table 7). Capturesuccess ranged from 26 to 76 trap-nights per grizzly bear and 28 to 51 trap-nights per black bear.

TABLE 6. Summary of grizzly and black bear captures in the Khutzeymateen study area, 1989–1991

New grizzly bears Grizzly Number radio-collared New black bears Black bearYear Males Females Total recaptures Males Females Males Females Total recaptures

1989 11 5 17a 1 3 4 17 0 17 11990 4 3 7 6 4 3 2 0 2 21991 3 2 5 1 4 2 8 1 9 0

Total 18 10 29 8 11 9 27 1 28 3

a A grizzly cub of unknown sex was captured in 1989.

TABLE 7. Summary of grizzly and black bear capture success in the Khutzeymateen study area, 1989–1991

Capturesa Trap-nights per capture

Grizzly Black All Total Grizzly Black AllYear bears bears bears trap-nights bears bears bears

1989 15b 18 33 495 33 28 151990 13 4 17 338 26 85 201991 6 9 15 455 76 51 30

Total 34 31 65 1288 38 42 20

a Includes recaptures.b Does not include GM11 caught on 11 June, GF34 caught on 25 September, or a cub-of-the-year caught on 6 October outside the

main trapping period.

5.1.1 Morphometrics

The physical measurements of all grizzly and black bears captured in the Khutzeymateen study areafrom 1989 to 1991 are summarized in Appendices 1 and 2, respectively. The mean spring weights ofgrizzly and black bears are summarized in Table 8. The mean spring weight of adult males is probablygreater than 231.3 kg because five of the nine captured were not weighed. These males were estimated tobe between 250 and 300 kg.

5.2 Seasonal Food Habits

5.2.1 Diet

Approximately 500 scats were collected over the 3-year study. Analysis was begun but notcompleted for this report. General food habits were determined from site investigations and fieldobservations. Table 9 is a list of all known grizzly bear foods (n=65) recorded in the Khutzeymateenstudy area from 1989 to 1991.

Sedges were the most frequently eaten food item from late April until early July (Figures 4–6).Skunk cabbage was eaten throughout the active period, but predominated in the diet during late June and


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July, and again in late September and October. Several Umbelliferae (cow-parsnip, beach lovage,kneeling angelica, hemlock parsley, and water-parsley) were common in the diet during mid- to late Juneand July, and cow parsnip was used again in late September and early October. Several herb species(stinging nettle, lady fern, and Mexican hedge-nettle) were commonly eaten from June to early Auguston avalanche slopes. Hedge-nettle, common horsetail, and common touch-me-not were eaten in wet-lands and on river bars from late June to late August.

TABLE 8. Mean spring weights of grizzly and black bears captured in the Khutzeymateen study area,1989–1991

Mean weightAge (kg) SD Range n

Grizzly bearsMales

3 113.2 22.6 75–135 54 141.7 4.7 135–145 36+ 231.3 36.8 190–260 4

Females4 100.0 15.0 85–115 2

12+ 131.3 17.5 112–151 6

Black bearsMales

5+ 86.7 19.5 48–135 26

The current year’s growth of a number of fruiting shrubs was eaten before berries became ripe. Theshoots of salmonberry and thimbleberry, the leaf buds and petioles of devil’s club, and the leaf petiolesof elderberry were commonly eaten. Feeding on new buds and shoots generally occurred from early Juneto mid-July (Figures 4–6).

All berry species in the Khutzeymateen study area were eaten by grizzly bears to various degrees,apparently depending upon local and annual abundance as well as relative availability. The frequencyand timing of use of different berries corresponded to the dates of ripening, which varied from year toyear and between species. The general chronological order of use was: salmonberry, huckleberry, redelderberry, devil’s club, stink currant, highbush-cranberry, red-osier dogwood, and Pacific crabapple.The berries most frequently fed upon were red elderberry, devil’s club, and stink currant. Berries wereprimarily eaten between early July and early September (Figures 4–6).

Runs of salmon began moving into the Khutzeymateen River in late July and early August andbecame the major food item of grizzly bears until mid- to late October (Figures 4–6). Bears fed uponfreshly killed spawning salmon, as well as the carcasses of spawned-out salmon. The general order of thesalmon ru

khutzeymateen valley grizzly bear study : final report...grizzly bear – british columbia –...

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