Ecological Studies of Wolves on Isle Royale - Annual Report 1985-1986 (Covering the twenty-eighth year of research)
Peterson RO. 1986. Ecological Studies of Wolves on Isle Royale - Annual Report 1985-1986 (Covering the twenty-eighth year of research). Isle Royale Natural History Association. Houghton, MI
Mechanisms of population regulation for Isle Royale wolves and moose remain the central interest in the long-term continuing study now entering its 29th year. Wolves on Isle Royale decreased slightly to 20 individuals in 1986 as one of the three territorial packs was displaced completely by a dominant pack. Survival rate for wolves present last year was 77%, not counting an adult female wolf killed by a pack during the winter study in 1986. Moose numbers in 1986 were estimated at 1025 (+/-) 108. The moose population has generally increased since 1982, although the rate of increase has apparently been slowed by wolf predation. Calf survival has remained relatively high since wolves crashed in 1982, and moose mortality is stable at a low level. Studies of radio-collared moose on the island will be largely concluded in 1986. Comprehensive studies of moose foraging and activity patterns in both winter and summer were completed, and the collared moose enabled researchers to determine the "sightability" of moose during the midwinter census, that is, the proportion of existing moose that are actually seen and counted on plots. Under present conditions, moose sightability during our winter census ranges from 75-95%, depending on the extent to which moose have moved into conifer cover.
- Type
- Published Report
- Authors
- Peterson, Rolf
- Date of Issue
- 1986-03-31
- Publisher
- Isle Royale Natural History Association
- Units
- ISRO
- Keywords
- Aerial Survey, Ecology, Gray Wolf (Canis lupus), Isle Royale National Park, Mammals, Michigan, Monitoring, Moose (Alces alces), Radio Collar