Wolf Population Dynamics and Prey Age Structure in Isle Royale National Park
Peterson RO, Page RE, Vucetich JA. Wolf Population Dynamics and Prey Age Structure in Isle Royale National Park. IN: Study of Wolf Decline, R O Peterson, 1994 Chapter 8. School of Forestry and Wood Products, Michigan Technological University. Houghton, MI
At large spatial and temporal scales wolf density is broadly correlated with prey density, consistent with expectations for a top carnivore. Yet during a 2-decade period annual fluctuations of wolf numbers in ISRO were not similar to fluctuations in moose, their primary prey. Moose population level was estimated from reconstruction based on recovery of dead animals (1959-1982), on aerial surveys (1983-1993), and on simulations based on an empirical model of moose population rate of change (1994-2000). Population reconstruction was based on a field effort with an estimated recovery rate of 33%, employing corrections for seasonal bias in field effort, variable field effort, and moose yet alive. Wolf population level in 1959-1980 was best predicted by density of old moose, which provide 67% of prey biomass for ISRO wolves, including a lag of 2 years for wolf response. Wolf numbers >1980 were lower than expected based onfood abundance, which reached a low point in ca. 1990 and is predicted to rise rapidly during 1990-2000.
- Type
- Published Report
- Authors
- Peterson, Rolf; Page, Richard; Vucetich, J
- Publisher
- School of Forestry and Wood Products, Michigan Technological University
- Units
- ISRO
- Keywords
- Animal Studies, Gray Wolf (Canis lupus), Moose (Alces alces), Population regulation, Predation