BEARS, WOLVES, MOOSE, AND FOREST SUCCESSION, SOME MANAGEMENT CONSIDERATIONS ON THE KENAI PENINSULA, ALASKA

Abstract

We compared population dynamics for moose (Alces alces) and black bear (Ursus americanus) in an older (1947) and recent (1969) burn from 1978-1988. Moose densities in the 1947 burn were moderately high in early years of study (1.3 moose/km²) but declined dramatically in later years (0.3 moose/km²) as habitat quality declined. Moose densities in the 1969 burn were high (3.3 - 3.7 moose/km²) in response to good habitat quality. Reproductive rates measured as percent of females with twins were 22 and 70% for the 1947 and 1969 burns. Estimates of neonatal moose calf survival using a Kaplan-Meier procedure were not different (P > 0.05) between the two areas (0.42 vs. 0.48). Predation accounted for 86% of all recorded mortalities; black bears accounted for 70% of all mortalities and 81% of all predation. Black bear density was similar in the two areas (205 vs. 258 bears/1000 km² in 947 and 1969 burns). Reproductive success measured as age of first litter production and interval between weaning of yearlings was significantly (P < 0.05) better in the 1969 burn. Cub survival was significantly lower (P < 0.05) in the 1947 burn. Mean body size of bears in the 1969 burn was significantly greater (P < 0.05) then in the 1947 burn. Better performance of bears in the 1969 burn was attributed to a greater availability of moose calves per bear which represented a significant source of high quality food during spring when other available foods were of lower quality. It appeared the high density moose population on the Kenai Peninsula was regulated by habitat quality and quantity. Wolf (Canis lupus) density was high (11-20/1000 km²) but not different between the two areas. Brown bears (U arctos) numbers in the two study areas were low (23 - 28/1000 km²) relative to black bears. Impacts of predation varied with changes in habitat carrying capacity and clearly defined management objectives determined when habitat enhancement or predator control was most appropriate.