A reappraisal of the evidence for regulation of wolf populations |
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Authors: | C A Cariappa John K Oakleaf Warren B Ballard Stewart W Breck |
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Institution: | 1. Department of Natural Resources Management, Texas Tech University, Box 42125, Lubbock, TX 79409-2125, USA;2. U.S. Fish and Wildlife Service, Mexican Wolf Field Projects Coordinator, P.O. Box 92, Alpine, AZ 85920, USA;3. USDA/Wildlife Services, National Wildlife Research Center, 4101 Laporte Avenue, Fort Collins, CO 80521, USA |
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Abstract: | The dogma that gray wolf (Canis lupus) population densities in naturally occurring systems are limited almost solely by available ungulate biomass is based upon studies that fit straight line linear regressions (Type 1 numerical response) to data collected at 32 sites across North America. We fit Type 1, 2, and 3 response functions to the data using linear and nonlinear regression as appropriate and found that the evidence supported wolf population regulation by density-dependence as much as limitation by prey availability. When we excluded 4 of 32 points from the original data set because those points represented exploited or expanding wolf populations the data suggested that wolf populations are self regulated rather than limited by prey biomass by at least a 3:1 margin. In establishing goals for sustainable wolf population levels, managers of wolf reintroductions and species recovery efforts should account for the possibility that some regulatory mechanism plays an important role in wolf population dynamics. © 2011 The Wildlife Society. |
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Keywords: | numerical response prey limitation regulation Type 1 Type 2 Type 3 wolves |
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