Use of Occupancy Models to Estimate the Influence of Previous Live Captures on DNA-Based Detection Probabilities of Grizzly Bears |
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| Authors: | JOHN BOULANGER GARY C WHITE MICHAEL PROCTOR GORDON STENHOUSE GRANT MACHUTCHON STEFAN HIMMER |
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| Institution: | 1. Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523, USA;2. Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada;3. Sustainable Resource Development, Fish and Wildlife Division, Box 6330, Hinton, AB T7V 1X6, Canada;4. 817 Mill Street, Nelson, BC V1L 4S8, Canada;5. Arctos Wildlife Services, Site 10, Comp. 7, R.R. 1, Crescent Valley, BC V0G 1H0, Canada |
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| Abstract: | Abstract: Large carnivores potentially change their behavior following physical capture, becoming less responsive to the attractants that resulted in their capture, which can bias population estimates where the change in behavior is not appropriately modeled. We applied occupancy models to efficiently estimate and compare detection probabilities of previously collared grizzly bears (Ursus arctos) with bears captured at DNA hair-snag sites that were not previously collared. We found that previously captured bears had lower detection probabilities, although their detection probabilities were still >0, implying that they were still visible to be sampled via the DNA hair-snag grid, which was able to detect finer differences in capture probabilities of previously collared bears compared with Huggins closed-captures population models. To obtain relatively unbiased population estimates for DNA surveys, heterogeneity caused by previous live capture should be accounted for in the population estimator. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):589–595; 2008) |
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| Keywords: | DNA sampling grizzly bear hair snags mark—recapture occupancy models Program MARK |
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