CONSIDERATIONS FOR INTENSIVE MANAGEMENT OF MOOSE IN ALASKA

Abstract

The Alaska Legislature recently passed a law directing the Alaska Board of Game to identify certain game populations that will be managed intensively. This mandate implies management for maximum sustained yield (MSY), yet managing populations for MSY is problematic. Over-harvest at MSY may cause populations to decrease to low levels, and in the presence of predation low density equilibrium can be established. We recommend maintaining intensively managed populations at densities above the actual point of MSY to avoid potential over-harvests caused by stochastic variation in recruitment. Managing intensively will require better information on factors that influence recruitment and corresponding rates of increase in moose populations, including: age at first reproduction; rates of pregnancy, twinning, age-specific survival, dispersal, and predation; as well as population sex ratios. Population modeling indicates that rate of increase is most sensitive to changes in adult survival, but under most circumstances in real moose populations, calf survival is very important. Factors affecting calf survival include habitat quality, weather, and predation, and the effects of these factors can be minimized by maintaining moose densities slightly above those which maximize recruitment. An intensive management strategy for moose populations in Alaska must include the ability to implement cow harvests, predator management, and habitat management. Aggressive monitoring of population parameters, cause-specific mortality rates, trends in habitat quality, and a knowledge of carrying capacity will be essential to selecting appropriate management strategies. Gaining this information will be expensive but the alternative is potential mismanagement and the risk of population declines.