Abstract: I studied the ecology of black bears (Ursus americanus) in the central Adirondack Mountains of New York. I examined the influence of food abundance and forest management on foraging habits, habitat selection, home range, denning, reproduction and survival.
Foraging habits were documented from scat analysis and observation. Plant foods constituted 90% of scat volume during 1988-1989. During spring, bears consumed grass, sedge, and other vegetation. The summer diet was dominated by fruits, especially red raspberry (Rubus ideaus). Beechnuts (Fagus grandifolia) and black cherries (Prunus serotina) were primary fall foods.
I sampled seasonal food abundance within 17 habitats and used food abundance indices to predict habitat selection. Even-aged managed and uneven-aged managed habitats provided the highest abundance of spring foods and summer fruits. Fall foods, especially beechnuts, were most abundant in non-managed and uneven-aged managed hardwood habitats. Seasonal shifts in habitat use by 5 adult female bears during 1989-1991 were related to changes in food abundance.
Mean annual home range size of 5 adult females was 31.2 km2 using minimum convex polygon (MCP) and 38.4 km2 using bivariate normal ellipse (BNE). Annual home range size of 1 adult male was 170.0 km2 using MCP and 383.4 km2 using BNE. Annual home range size was not affected by food abundance, however a decrease in summer home range size coincided with high fruit abundance.
Most adult female bears entered dens during mid-November and emerged during early April. Mean denning period was 141.1 days (n = 8). Denning dates did not differ by year or reproductive status of the female.
Mean litter size in dens was 3.0 (n = 3) cubs and 2.0 (n = 2) yearlings. Mean known interbirth interval was 2.5 years (n = 2). No significant relationship among litter size, litter production, female weight, and food abundance were observed.
Yearling survival was affected by food abundance. A yearling female apparently died of starvation and a yearling male was killed after foraging on human-foods.
I formulated a model for predicting beechnut production by individual trees. This model estimated that beechnut production in a non-managed stand was reduced by 37% as a result of beech bark disease.
The relationship of forest management to black bear habitat ecology and management implications were discussed.