Demography and Movements of Wolves in Relation to the Western Arctic Caribou Herd of Northwest Alaska Research Progress Report

Ballard, Warren; Ayres, Lee; Fancy, Steven; Reed, Daniel; Roney, Kathryn; Spindler, Michael

During April 1987 a pilot study was initiated to determine the status of the wolf population and to examine the feasibility of conducting a wolf demography and survey techniques investigation in northwest Alaska. Eleven wolves in 6 packs were captured and radio collared; 1 of which was fitted with a prototype satellite collar. Autumn 1987 wolf density was estimated at 4.4 wolves/1,000 km^2 and the wolf population appeared to be increasing. Consequently a more intensive study was initiated in April 1988. Between April 1988 and April 1989 a total of 49 wolves have been captured and radio collared within 13 packs. Sex ratios of pups were skewed in favor of females while other ages were not different from 50:50. From April 1987 through June 1989 the 13 packs have been relocated a total of 1,012 occasions with conventional telemetry methods. Territory sizes of 4 packs ranged from 950 km^2 to 2,358 km^2. During the first year of study all study packs maintained year-round territories. During the 2nd year of study at least 2 of 6 packs migrated 170-230 kms south; an apparent attempt to follow migrating caribou. Caribou and moose were the major prey species. When caribou were present within pack areas caribou was the predominant prey killed whereas when caribou migrated and few were present moose were the primary species killed. Wolf densities ranged from a low 2.7/1,000 km^2 in spring 1987 to a high of 6.3/1,000 km^2 during autumn 1989. Seven satellite collars were tested during 1987-89; 1 in 1987-88 and 6 in 1988-89. Two of the seven collars failed. The first collar performed flawlessly and resulted in 415 revocations and 747 sets of sensory data. During 1988-89 the 6 satellite collars, referred to as pits, transmitted for varying lengths and provided 1,606 relocations and at least 2,063 sets of sensory data. Wolf pit's had an average life span about 10 months. Transmission duty cycles were compared and VHF collars which transmitted 6 hours per transmission provided a greater number of usable relocations than those transmitting for only 4 hours. An average of 26 locations per month were obtained with either a 4 or 6 hour transmission cycle. Evaluation of satellite transmitters for monitoring wolf movements will continue. Several wolf census methods will be tested in 1990.