NATIONAL PARK SERVICE Demography of Grizzly Bears in Relation to Hunting and Mining Development in Northwestern Alaska

Conservation of brown or grizzly bears (Ursus arctos) in Alaska is partially dependent on the availability and use of assessment methods that allow resource managers to monitor the status of populations on a regular basis. Historically, managers have relied primarily on gross analysis of harvest data and miscellaneous observations to assess bear population trends and harvest effects. The basis for use of harvest statistics for monitoring population status, however, is not well documented and seems to be imprecise and unreliable (Harris 1984; Harris and Metzgar 1987a, 1987b). In areas where unreported harvests are potentially large, reported harvests may not represent patterns of population mortality. Consequently, problems associated with analysis of harvest data for assessing population trends may be insurmountable. Fortunately, bear populations seem healthy and abundant in many areas of Alaska (Peterson 1987). With scientific management, however, appropriate methods must be developed and tested so that managers can confidently identify and remedy population declines or allow opportunities for additional harvest as the situation warrants.

Human populations have significantly increased while the abundance and distribution of grizzly bears in North America have significantly decreased (Cowan 1972). Although abundance and distribution of bears in Alaska have changed little from historical times, significant changes in the environment or human distribution could permanently alter the productivity and survival of some Alaskan populations. Current knowledge about the effects of resource development activities on grizzly bear populations is inadequate to provide effective guidelines to agencies and private companies for minimizing and mitigating human effects to bear populations. This inadequacy exists because such effects are usually long term, and research is usually of short duration; and many effects have occurred relatively recently and have not been investigated (Peek et al. 1987).

Our study was conceived because of conflicting testimony received from the public concerning bear abundance and potential adverse effects from development and operation of the Red Dog Mine in northwestern Alaska. The study was designed to evaluate effects of hunting on bear populations. We desired to compare bear densities with known reported harvests and to provide baseline data on population density, sex and age structure, movements, and reproduction parameters before large-scale development of the Red Dog Mine. Actual effects from the mine and other associated developments were to be assessed at a later date by repeating the study using identical methods. Obtaining an accurate and precise estimate of the bear density in the potential affected area was the key objective of this research effort.