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

During 1986 through 1990, we studied demography and movements of grizzly bears in the 6,700-km² Noatak River study area that encompassed the Red Dog Mine Project (Fig. 1). The Red Dog Mine Project is a joint venture between the Northwest Alaska Native Association Regional Corporation (a local private native Corporation) and Cominco Alaska, Inc. The project includes an open-pit lead and zinc mine located on Red Dog Creek 131 km north of Kotzebue (Fig. 2). In addition to the mine, the project includes tailings ponds, mill, power plant, worker housing, water reservoir, at least 90 km of gravel road, a saltwater port, and several gravel borrow sites (Environmental Protection Agency and U.S. Department of the Interior 1984). At normal production levels, a minimum of one large truck will pass on the road to port every 45 min. The project is expected to last more than 40 years, 225-250 employees will occupy the site at any one time. The transportation corridor may accommodate a railroad in future years. Easier human access to remote areas is expected to result in an increase in human use and an additional "long-term increase in natural resource productivity in the western Brooks Range (e.g., hard rock minerals, coal, oil, and gas)" (Environmental Protection Agency and U.S. Department of the Interior 1984). More than 18,000 mining claims exist within the area. Ore production began begin in winter 1989, but full production did not begin until late fall 1990.

Fig. 1. Location and boundaries of the Noatak River study area where grizzly bears were studied during 1986 through 1990 in northwestern Alaska.

Fig. 2. Map of the Red Dog Mine project in northwestern Alaska as envisioned at the beginning of full ore production in 1990.

The NRSA includes portions of Cape Krusenstern National Monument in the south and Noatak National Preserve in the northeast (Fig. 3). The NRSA is managed administratively by two federal agencies, one state agency, one regional native corporation, and two village corporations. Cape Krusenstern National Monument and Noatak National Preserve are administered by the National Park Service, and the federal lands lying between the two units are managed by the Bureau of Land Management. State lands are managed by the Alaska Department of Natural Resources. Sport and subsistence hunting for grizzly bears is allowed within the NRSA except within Cape Krusenstern National Monument, where only subsistence hunting is allowed. Exploitation of nonrenewable resources is not allowed on National Park Service units.

Fig. 3. Land ownership in and adjacent to the Noatak River study area in northwestern Alaska.

The NRSA is characterized by a polar maritime climate along the coast and a continental type climate inland. Summer temperatures range from 2.2 to 32.2° C, and winter temperatures have been as low as —47° C. Extremely low winter temperatures occur less frequently in the mountains because of temperature inversions. Annual precipitation averages from 25 cm along the coast to 51-76 cm in the mountains; half of it occurs in July through September. Snow cover usually occurs from mid-October through mid-May. Elevation ranges from sea level to 1,212 m. Elevation increases from flat lowlands near saltwater and major river systems at the southern end of the study area; it grades into moderately sloping foothills, then to steep, rocky mountains separated by narrow valleys in the north. Permafrost underlies much of the area. Trees are absent except along the Noatak and Kelly river floodplains. Caribou (Rangifer tarandus), moose (Alces alces), and Dall sheep (Ovis dalli) occur within the study area and serve as prey or carrion for grizzly bears. No black bears (Ursus americanus) have been observed. All of the major rivers and their tributaries provide fish that are an important seasonal source of food for bears. Arctic char (Salvelinus alpinus), grayling (Thymallus arcticus), pink salmon (Oncorhynchus gorbuscha), and chum salmon (O. keta) are predominant species. Salmon migration usually occurs from July through September each year. Late fall chum salmon runs seem particularly important because they provide food for bears just before denning. The late chum runs in the Noatak area are some of the latest in North America (C. Lean, Alaska Department of Fish and Game, Nome, personal communication) and probably have a relation to bear densities. A number of bears appeared to forage on marine mammal carcasses, such as beluga whales (Delphinapterus leucas), walrus (Odobenus rosmarus), and several species of seals (Phoca spp.), that wash up onto the Chukchi Sea coastal beaches each spring and summer.

We selected the NRSA boundaries to encompass an area receiving a moderate amount of bear hunting pressure. Because the NRSA was much too large for effectively conducting an intensive census, we selected a smaller area based on movements of radio-collared bears in 1986 and location of the mine and associated roads (Fig. 4). This smaller area is referred to as the Red Dog Mine count area or just count area.

Fig. 4. Boundaries of count areas used to survey grizzly bears within the Red Dog Mine census area of northwestern Alaska from 29 May through 4 June 1987.

The count area was characterized by steep, mountainous terrain traversed by several major rivers and creeks. Vegetation types ranged from riparian stands of willow (Salix spp.), birch (Betula nana, B. glandulosa, and B. spp.), and cottonwood (Populus balsamifera) along the streams and rivers to closed and tall shrub, low shrub, open low shrub, tundra, and then bare rock and ice as elevation increased. Relatively thick stands of white spruce (Picea mariana) occurred within the southern half of count areas 3, 4, and 8 along the Noatak River and near the mouths of Wrench and an unnamed creek (i.e., No Name Creek) in count area 10. Elevations within the count areas ranged from approximately 62 m along the southern boundary to 1,183 m along the northern boundary. The count areas (1-10) included the den sites of seven radio-collared bears. All of the census area was considered usable bear habitat, although the northern half of the area was probably more representative of high-quality denning habitat rather than habitat used on a year-round basis. Only a relatively small portion of the census area encompassed areas above 909 m that were considered to be poor bear habitat in this portion of Alaska. Consequently, the entire area was used for calculation of a density estimate.