Ecological Studies of Wolves on Isle Royale - Annual Report 1986-1987 (Covering the twenty-ninth year of research)
Peterson RO. 1987. Ecological Studies of Wolves on Isle Royale - Annual Report 1986-1987 (Covering the twenty-ninth year of research). Isle Royale Natural History Association. Houghton, MI
Wolves declined while moose and beaver increased during 1987-1987, the 29th consecutive year of research into wolf-moose dynamics at Isle Royale. Wolf numbers stood at only 16 in 1987. Mortality rate for the wolves present last year was 40-45%, very high for a protected wolf population. The nature of this mortality is unknown, but low kill rate, extensive trespassing, and continued interpack conflict all point to a chronically low food supply. Only two wolf packs persisted through the 1987 study. The moose population was estimated at 1380 (+-) 204, siggesting a substantial increase over last year. Calf recruitment in 1986 was strong, especially on the east ens of the island where wolf density has plummeted within the last two years. Overall, moose mortality is low. Radio-collared moose were used in 1987 to continue an assessment of moose "sightability" on census plots, or the proportion of moose seen and counted on plots.
- Type
- Published Report
- Authors
- Peterson, Rolf
- Date of Issue
- 1987-03-31
- 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