Marine Mammals Management
Alaska Region


Polar Bear

Polar Bear Feeding Ecology Study

Polar bears are an integral component of the marine environment and serve as an indicator of contamination, climate change, and other potential changes to the Arctic ecosystem. Polar bears spend most of their time on drifting Whale cutting. Credit: Susanne Miller/USFWS.pack ice and feed primarily on ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus). In Alaska, polar bears have also been observed feeding on stranded marine mammal carcasses during fall months while traveling along the coast and barrier islands of the Beaufort, Chukchi, and Bering seas. The near shore environment is an area that is subject to oil and gas development and other human activities that have the potential to impact polar bears and their foraging habits.

Native residents of the North Slope of Alaska consistently harvest bowhead whales (Balaena mysticetus) for subsistence purposes in the fall. Large numbers of polar bears congregate at whale harvest sites near the villages of Kaktovik, as well as near Barrow, and at Cross Island (the village of Nuiqsut’s bowhead whale hunting camp) and other barrier islands along the Beaufort Sea. Marine mammal carcasses provide tons of potential food for polar bears and may be an important food source before the onset of winter. Supplemental food sources such as stranded marine mammal carcasses may enhance the survival of nutritionally stressed bears. In turn, use of carcasses may be linked to reproductive success of female polar bears, which is critical to the continued health and stability of the population.

The FWS, with Minerals Management Service funding, is conducting a three-year study on polar bears using Barter and Cross Islands during fall months (late open water season) using coastal areas of the Beaufort Sea. The objectives of the study are to: Polar Bear feeding. Credit: Scott Schliebe/USFWS.

  1. determine the number, age and sex composition of polar bears;
  2. record habitat use and behavior of polar bears; and
  3. determine the magnitude of interchange of polar bears between Barter Island and Cross Island.

The Alaska Nanuuq Commission, North Slope Borough, and Native villages of Kaktovik and Nuiqsut are cooperators on the study. Field crews conducted observations of polar bears during 2002 and 2003. Observations were made by a combination of scan, continuous, and focal sampling, as well as direct observations, and video and still photography.

A preliminary report is available by contacting Susanne Miller at 1-800-362-5148. A final report will be ready in 2005 pursuant to additional field work currently scheduled for September 2004.

Last updated: September 10, 2008