Marine Mammals - Sounds Wild


Download Episode: Walrus (MP3 file 3,520 kB)



On a summer day, hundreds of walrus swim in the waters near Round Island, part of the walrus island complex in the Bering Sea west of Dillingham. Most walrus move north to the Arctic waters of the Chukchi Sea in the summer, but a number of males stay at the Walrus Islands in northern Bristol Bay. Their unusual belling and gonging calls can be heard as they forage in the waters around the island. Walrus feed on clams that they excavate from the sea floor - they use their sensitive, bushy whiskers to locate the mollusks and they literally suck them up out of the sea bottom mud. The walrus's distinctive tusks are not used for foraging or feeding.

Walrus move seasonally following the retreat and advance of ice - most of the population moves north in the spring and migrates south in the fall. The animals rest on the edge of the sea ice between bouts of foraging. Recent reductions in the extent, thickness, and duration of the summer sea ice may have profound effects on walrus distribution, movement patterns, and feeding opportunities, as less ice is available for a resting platform.

Biologists are working to learn more about walrus, their numbers, and these seasonal movements. A 1990 census of the Pacific walrus population indicated about 200,000 animals. Russian and American biologists recently conducted new, updated survey in the Chukchi and Bering seas. Russian biologists deployed about 40 satellite tracking tags on walrus in 2007, and this year, U.S. researchers tagged 70 walruses in Alaska to gain insights into walruses foraging areas, sea ice habitats and movements.