- McLaughlin, Craig
The Graduate School The University of Maine
Black bears (Ursus americanus) are an economically important big game species in Maine. Nuts of the American Beech (Fagus gradifolia) are their primary fall food in northern Maine. Beechnut production varies annually, with alternate-year crop failures. The future of this food supply is uncertain, as disease and trends in timber harvest may reduce numbers of nut-producing beech trees.
I examined effects of harvests on population growth by setting litter production to High, Moderate, Alternating High-Low, and Low in turn, and incrementally increasing hunting mortality. Populations with the highest vital rates recorded in Maine sustained 15% hunting mortality; those with alternate-year litter production could not sustain 5% mortality. Litter Production, age of first reproduction, and adult mortality should be monitored to assess the nutritional planes, trends, and harvest potential of female black bear populations.