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Use of Occupancy Models to Estimate the Influence of Previous Live Captures on DNA‐Based Detection Probabilities of Grizzly Bears
Author(s) -
BOULANGER JOHN,
WHITE GARY C.,
PROCTOR MICHAEL,
STENHOUSE GORDON,
MACHUTCHON GRANT,
HIMMER STEFAN
Publication year - 2008
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.2193/2006-447
Subject(s) - occupancy , grizzly bears , ursus , population , estimator , snag , geography , population size , statistics , ecology , biology , habitat , mathematics , demography , sociology
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)