Ecological Studies of the Wolf on Isle Royale - Fourth Annual Report (Covering the sixteenth year in the Isle Royale studies), 1973-1974
Peterson RO and Allen DL. 1974. Ecological Studies of the Wolf on Isle Royale - Fourth Annual Report (Covering the sixteenth year in the Isle Royale studies), 1973-1974. Department of Forestry and Conservation, Purdue University. West Lafayette, IN
This report summarizes the Summer, 1973 and Winter, 1974 wolf/moose field work on Isle Royale. The summer work included collections of moose remains and of quantification of wolf scats on hiking trails (as an indication of wolf avoidance of trails when humans use the trails). Examination of scats showed the importance of beaver as a summer food item for wolves. During Winter Study the wolf population was estimated at 31, partitioned into the two packs, one duo, and one loner. This was the highest wolf population recorded since these systematic studies began on Isle Royale in 1959. Excellent pup survival in the two packs was attributed to the ample availability of moose calves and beaver during the 1973 rearing season. The West Pack split into four groups by late winter, probably due to a change in leadership. The 1974 aerial moose census estimated the population at 875, slightly more than the last census in 1972. Based on results from Alaska, which show that such aerial estimates are at least 20% low, a recalculation of moose numbers for 1972 and 1974 places both estimates near 1000.
- Type
- Published Report
- Authors
- Peterson, Rolf; Allen, Durward
- Date of Issue
- 1974-04-30
- Publisher
- Department of Forestry and Conservation, Purdue University
- Units
- ISRO
- Keywords
- Aerial Survey, Ecology, Food Preferences, Gray Wolf (Canis lupus), Isle Royale National Park, Mammals, Michigan, Monitoring, Moose (Alces alces), Population Dynamics, Predation