Density estimation in a wolverine population using spatial capture-recapture models

Journal of Wildlife Management
By: , and 
Edited by: Kevin McKelvey



Classical closed-population capture-recapture models do not accommodate the spatial information inherent in encounter history data obtained from camera-trapping studies. As a result, individual heterogeneity in encounter probability is induced, and it is not possible to estimate density objectively because trap arrays do not have a well-defined sample area. We applied newly-developed, capture-recapture models that accommodate the spatial attribute inherent in capture-recapture data to a population of wolverines (Gulo gulo) in Southeast Alaska in 2008. We used camera-trapping data collected from 37 cameras in a 2,140-km2 area of forested and open habitats largely enclosed by ocean and glacial icefields. We detected 21 unique individuals 115 times. Wolverines exhibited a strong positive trap response, with an increased tendency to revisit previously visited traps. Under the trap-response model, we estimated wolverine density at 9.7 individuals/1,000-km2(95% Bayesian CI: 5.9-15.0). Our model provides a formal statistical framework for estimating density from wolverine camera-trapping studies that accounts for a behavioral response due to baited traps. Further, our model-based estimator does not have strict requirements about the spatial configuration of traps or length of trapping sessions, providing considerable operational flexibility in the development of field studies.

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Publication type Article
Publication Subtype Journal Article
Title Density estimation in a wolverine population using spatial capture-recapture models
Series title Journal of Wildlife Management
DOI 10.1002/jwmg.79
Volume 75
Issue 3
Year Published 2011
Language English
Publisher The Wildlife Society
Publisher location Bethesda, MD
Contributing office(s) Patuxent Wildlife Research Center
Description 8 p.
First page 604
Last page 611
Country United States
State Alaska
Other Geospatial Southeast Alaska
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