Pacific Walrus

Pacific Walrus

Lifestyle

Built for the extreme conditions of the Arctic Circle, walruses spend about two-thirds of their lives in frigid waters, and the other third on frosty land. They are strong and graceful swimmers, able to dive down to 260 feet to feed on the ocean floor. Generally, they forage underwater for 2 to 10 minutes at a time, then haul out on ice or land to rest. They use their tusks and flippers for traction on slippery surfaces.

Walruses migrate with the pack ice, traveling south during the Arctic winter and north during the spring. Gregarious creatures, thousands can be seen packed right up against each other on ice floes and beaches. Except for during breeding season, these herds are usually separated by sex, so mothers with calves stick together, and adult males stick together.

Food

Walruses mainly eat krill, clams, and mussels. They root out their meals from the ocean floor, squirting water from their mouths to blast the shellfish out of the mud. Walruses have weak vision but use their vibrissae—the stiff bristles around the snout—to find food.

Life Cycle

During mating season, males, or bulls, court females with elaborate, booming songs, a bit like humpback whales. They make bell-like sounds underwater, and whistle above water. They also drum on their chests with their flippers. After mating, a walrus mother’s gestation lasts about 15 months in total. Calves generally arrive around June, when environmental conditions are optimal for survival. After a walrus gives birth, she joins a group of other mothers and young. There is some evidence of community caregiving, but walrus rearing is mostly a one-parent job. Mothers and calves typically stay together for at least two years. Females usually remain with their mother’s herd, but after an additional two or three years, young males join an all-male herd. Walruses can live to be 30 years old.

Some of My Neighbors

Polar bears, harp seals, ring seals, belugas, bowheads, narwhals

Population Status & Threats

An estimated 250,000 Pacific and 50,000 Atlantic walruses remain in the wild. Because they depend on the seasonal ice caps, they are threatened by global warming. When the Arctic pack ice melts, they have no place to rest. Mothers with calves are especially affected by diminishing ice. In addition, if the pack ice retreats from the shallow, productive waters in the Bering Strait to deeper waters that walruses cannot access, they will starve.

WCS Conservation Efforts

WCS landscape ecologists have worked with researchers from the United States Geological Service to create a Geographical Information Systems (GIS) map of the changes in sea ice habitat over time. The map will help scientists distinguish short-term, seasonal effects and large-scale climate phenomena from the long-term global warming trends that threaten Arctic wildlife. Conservationists will then be able to predict where the ice is likely to remain solid in the near future, and how this will affect the many species that depend on it.