Ecology of the Badger (Taxidea taxus jeffersonii) in the Thompson Region of British Columbia: Implications for Conservation by Corinna Sara Hoodicoff Bachelor of Natural Resource Science, University-College of the Cariboo, 1998 A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in the Department of Biology We accept this thesis as conforming to the required standard Dr. K.W. Larsen, Supervisor (Adjunct, Department of Biology) Dr. P.T. Gregory, Co-Supervisor (Department of Biology) Dr. D. Duffus, Outside Member (Department of Geography) R.D. Weir, Outside Member Dr. D.S. Eastman, External Examiner (Department of Environmental Studies) © Corinna Sara Hoodicoff, 2003 University of Victoria All rights reserved. This thesis may not be reproduced in whole or in part, by photocopy or other means, without the permission of the author. ii Supervisor: Dr. Karl W. Larsen ABSTRACT My objective in this thesis was to fill knowledge gaps in badger (Taxidea taxus jeffersonii) ecology in British Columbia, in order to address conservation initiatives for the subspecies. I found that badgers used large home ranges (95% fixed kernel, x¯ = 28.6 km2, n = 7), and this was related to long-distance movements made during the breeding season. Badgers burrowed in habitats that were dominated by grass and supported abundant prey, but individuals exhibited plasticity of habitat use that depended on available resources. Within home ranges, badgers used certain areas more intensively (core areas) than others, particularly sites that reliably had prey and patches of suitable burrowing habitat. Badgers were relatively tolerant of humans, and used anthropogenically altered landscapes where there was sufficient prey. Conservation of badgers in British Columbia will depend reversing the negative impacts of humans, and on raising awareness of the ecological role of badgers in grasslands. iii Examiners: Dr. K.W. Larsen, Supervisor (Adjunct, Department of Biology) Dr. P.T. Gregory, Co-Supervisor (Department of Biology) Dr. D. Duffus, Outside Member (Department of Geography) R.D. Weir, Outside Member Dr. D.S. Eastman, External Examiner (Department of Environmental Studies) iv Table of Contents Title Page.........................................................................................................................i Abstract ..........................................................................................................................ii Table of Contents...........................................................................................................iv List of Tables ................................................................................................................vii List of Figures................................................................................................................ix Acknowledgements........................................................................................................xi Chapter One .............................................................................................................. 1 Introduction................................................................................................................... 1 1.1 BACKGROUND....................................................................................................1 1.2 BADGER ECOLOGY............................................................................................4 1.3 STUDY AREA..................................................................................................... 11 1.4 REFERENCES CITED ........................................................................................ 14 Chapter Two............................................................................................................ 20 Patterns of Spatial Use by Badgers (Taxidea taxus jeffersonii) in South-Central British Columbia, Canada .......................................................................................... 20 2.1 INTRODUCTION................................................................................................ 20 2.2 METHODS .......................................................................................................... 22 2.3 RESULTS............................................................................................................ 28 2.4 DISCUSSION ...................................................................................................... 33 2.5 CONCLUSIONS.................................................................................................. 38 2.6 REFERENCES CITED ........................................................................................ 39 v Chapter Three......................................................................................................... 45 Habitat Selection and Characteristics of Badger (Taxidea taxus jeffersonii) Burrows in South-Central British Columbia, Canada.............................................................. 45 3.1 INTRODUCTION................................................................................................ 45 3.2 METHODS .......................................................................................................... 47 3.3 RESULTS............................................................................................................ 52 3.4 DISCUSSION ...................................................................................................... 60 3.5 CONCLUSIONS.................................................................................................. 64 3.6 REFERENCES CITED ........................................................................................ 65 Chapter Four........................................................................................................... 69 Conclusions and Conservation Issues......................................................................... 69 4.1 CONCLUSIONS.................................................................................................. 69 4.2 LIMITATIONS OF THIS STUDY....................................................................... 71 4.3 CONSERVATION CONCERNS ......................................................................... 73 4.4 RECOMMENDATIONS FOR FUTURE RESEARCH ........................................ 81 4.5 REFERENCES CITED ........................................................................................ 83 Appendix I................................................................................................................ 86 A Two-Step Process to Determine Accurate Core Areas........................................... 86 I.1 INTRODUCTION................................................................................................ 86 I.2 METHODS .......................................................................................................... 88 I.3 DISCUSSION ...................................................................................................... 95 I.4 REFERENCES CITED ........................................................................................ 98 Appendix II ............................................................................................................ 102 S Code to Calculate Index of Aggregation ............................................................... 102 II.1 STEP 1: Generating simulated datasets using Monte Carlo methods................... 103 II.2 STEP 2: Calculating the Index of Aggregation and Probability Values ............... 104 II.3 REFERENCES CITED ...................................................................................... 105 vi Appendix III .......................................................................................................... 106 Food Habits of Badgers in the Thompson and Okanagan Regions of British Columbia ................................................................................................................... 106 III.1 INTRODUCTION.............................................................................................. 106 III.2 METHODS ........................................................................................................ 107 III.3 RESULTS.......................................................................................................... 109 III.4 DISCUSSION .................................................................................................... 112 III.5 REFERENCES CITED ...................................................................................... 114 vii List of Tables Table 2.1 Age-class and sex of badgers captured, and telemetry monitoring data for each animal. Both 100% minimum convex polygons (100% MCP), and 95% fixed kernel estimates (95% FK) were calculated from the independent locations (n) collected for each animal. An * in the Animal ID column indicates those badgers included in both fixed kernel and core area analysis................................................................. 29 Table 2.2 Index of aggregation results for all seasons (1999 – 2002), and for the summer (Apr 1–Aug 31). The index value (R) indicates the degree of aggregation of telemetry locations collected and the probability of the modeled index (p). The number of locations used in the analysis is represented by n. Index values for B06 and B14 were calculated during the summer only because there were no locations collected during other seasons. .............................................................................