THE DENALI UNGULATE-PREDATOR SYSTEM

Abstract

During 1981-85, moose (Alces alces), caribou (Rangifer tarandus), wolf (Canis lupus), Dall sheep (Ovis dalli), and grizzly bear (Ursus arctos) numbers were evaluated within the entire range of the Denali caribou herd and within the expanded Denali National Park and Preserve, Alaska. Wolf numbers were about to double in the 1930’s when caribou populations were 10 times higher. Caribou populations in 1984 were about 2,600 and were recovering, but the population size was 20,000-30,000 in 1917-40. The decrease availability of caribou as prey for wolves was apparently reflected in a 27% decline in mean wolf pack size and a 40% decline in mean litter site that occurred after 1975. Moose increased dramatically in the western and central park from 1974 to 1984, but declined about 32% in the eastern. Caribou availability may have influenced moose status. Caribou have been more available as alternate prey since 1980 in the areas where moose increased but were unavailable in the eastern park where moose declined.