Ecological Studies of Wolves on Isle Royale - Annual Report 2002-2003
Peterson RO and Vucetich JA. 2003. Ecological Studies of Wolves on Isle Royale - Annual Report 2002-2003. Annual Report. School of Forest Resources and Environmental Science, Michigan Technological University. Houghton, MI
During 2002-2003, the wolf population on Isle Royale increased slightly, from 17 to 19 individuals, while the moose population decreased slightly, from about 1,100 to 900, reflecting relative stability over the past three years. Three reproducing packs continue to occupy territories similar to those of 2002, although there was considerable turnover and poor reproduction in the East Pack, as its territory shrank in the face of challenge from the adjacent Chippewa Harbor Pack. An estimated seven pups survived in three litters, so five (29%) of the seventeen wolves present in 2002 perished, a mortality slightly above average. The moose population is currently very young, and wolf food supply (especially moose over 10 years old) will not increase until approximately 2007. Wolves were able to maintain midwinter kill rates at or above average levels. An outbreak of winter ticks led to higher moose mortality last spring, followed by reduced recruitment in the 2002 cohort. Another contributing factor was a late and cold spring in 2002. During the winter of 2002-2003, there were record-low snow depths, air temperature was unusually low, and wind speed was above average.
- Type
- Published Report
- Authors
- Peterson, Rolf; Vucetich, John
- Date of Issue
- 2003-03-31
- Publisher
- School of Forest Resources and Environmental Science, Michigan Technological University
- Units
- ISRO
- Keywords
- Aerial Survey, Beaver (Castor canadensis), Ecology, gray wolf (Canis lupis), Isle Royale National Park, Mammals, Michigan, Monitoring, Moose (Alces alces), Radio Collar