Roosevelt elk (Cervus canadensis) have important subsistence, sport, economic, and ecological value for residents and non-residents of Alaska. Factors that may limit Roosevelt elk populations include availability and quality of forage, and abundance and distribution of thermal cover, which are influenced by forest management. The spatial and temporal availability of these resources can influence elk distribution. For example, elk may shift habitat use to older forest stands with high canopy cover during winter to facilitate thermoregulation and reduce energy expenditure. Alternatively, in spring and summer elk may select edges between relatively open areas that provide forage and densely vegetated areas that provide escape cover. Anthropogenic alterations (e.g., commercial timber harvest) of elk habitat can affect the availability of forage and thermal cover, though ungulates can benefit from logging due to increased abundance of browse after timber harvest. Understanding factors potentially influencing elk distribution and abundance, and how they vary among forest successional stages and management practices, is critical for developing effective forest management strategies which incorporate elk resource requirements.
While the effects of forest management on elk have received considerable attention, much of this research emphasized Rocky Mountain elk (Cervus canadensis nelsoni). Due to divergent evolutionary histories, important differences in behavior, physiology, and habitat requirements may exist. These differences may preclude biologists from applying management strategies suitable for Rocky Mountain elk to Roosevelt elk populations.
Commercial logging on Afognak Island occurred in the 1930s and became extensive since 1979, resulting in a mosaic of forest stands of varying age. However, the effects of this habitat alteration on elk are unknown. In addition to forest management practices, brown bears (Ursus arctos) can influence elk calf survival as well as elk distribution and resource use. Therefore, a secondary area of study includes characterizing potential impacts of logging on brown bear in relation to elk resource use.
Our overall goal is to identify habitat conditions and forest management practices that can enhance wildlife habitat and provide sustainable wildlife harvests. We will examine elk and brown bear distribution, space use, and resource abundance on Afognak and Raspberry Islands in unharvested and harvested forest stands to identify resource attributes important to these species.
- Estimate spatial and temporal availability of resources and their effects on elk space use.
- Examine elk movements and energetic costs across varied landscapes.
- Estimate seasonal diet of elk.
- Investigate brown bear space use relative to forest management, and elk movements and vulnerability (e.g., calving), to identify areas of increased elk risk.
- Formulate resource use models to develop recommendations for long-term management of sustainable logging, elk and brown bear populations, and sport and subsistence harvest opportunities.
The Kodiak Archipelago consists of 25 islands comprising 13,882 km2 south of mainland Alaska. The largest island in the archipelago is Kodiak (57.4912° N, 153.4950° W; 9,311 km2). Kodiak and surrounding islands have a subarctic maritime climate with average annual high and low temperatures of 7.9°C and 1.9°C, respectively. Archipelago-wide average annual rainfall is 198.2 cm and snowfall is 173.0 cm. Elevations on Kodiak Island range from 0 to 1,362 m. The island is heavily forested in the north and east, with open tundra in the south. About 13,500 people live on Kodiak Island, with 7,000 in the city of Kodiak. Commercial fishing is the dominant industry and includes 5 species of Pacific salmon (Onchorynchus spp.), Pacific halibut (Hippoglossus stenolepis), and crab. Numerous rivers are famous for salmon fishing and island-wide annual escapement counts typically range from 4.6 to 5.9 million salmon. Logging, ranching, fish processing, and copper mining also occur on Kodiak Island. The island supports native brown bears as well as introduced populations of mountain goats (Oreamnus americanus), black-tailed deer (Odocoileus hemionus), bison (Bison bison), and captive elk.
Afognak Island (58.3279° N, 152.6415° W) (1,809 km2) is the second largest island in the Kodiak Archipelago and is located 5 km north of Kodiak Island. The island has varying terrain ranging from steep mountains rising to 739 m along the western side, to generally flat and rolling hills in the interior and east. It has rocky shores and Sitka spruce (Picea stichensis) is the dominant tree species. Devil’s club (Oplopanax horridus), blueberry (Vaccinium ovalifolium), salmonberry (Rubus spectabilis), and willow (Salix spp.) comprise much of the understory. Afognak Island has about 200 year-round residents located primarily in two logging camps. The island was set aside by President Benjamin Harrison in 1892 as a fish culture, forest, and wildlife preserve. Pacific salmon spawn throughout several of the island’s streams and lakes. The average annual salmon escapement for the island ranges from 414,000 to 510,000. Black-tailed deer were released on Kodiak Island in the early 1900s and expanded their range to Afognak Island by the 1950s. Eight Roosevelt elk were released on Afognak Island in 1929 and the current population is about 840 individuals. Elk hunting on Afognak Island is by permit only. Brown bears are common on Afognak Island, but the population size is unknown.
Raspberry Island (58.0708° N, 153.1876° W; 197 km2) is located 1 km southwest of Afognak Island and 5.6 km north of Kodiak Island. The highest elevation is 1,006 m and the island is dominated by alder (Alnus spp.), salmonberry, grasses, and scattered Sitka spruce forests. Along with a herd of about 210 Roosevelt elk, black-tailed deer and brown bears are common. Pacific salmon spawn throughout several of the island’s streams and lakes. Land ownership of Afognak and Raspberry Islands includes native corporations (64%), state government (27%), and federal government (9%).
Afognak and Raspberry Islands, Alaska, USA.