As spring presses the ice northward, females and subadults follow leads into the Chukchi Sea. Most adult males remain south in open water for the summer, hauling out on several islands and spits in the Gulf of Anadyr and Bristol Bay. Young are born in the spring on the ice. Females are six or seven years old before they breed, and then bear a single calf every two to three years. This reproductive rate is one of the lowest in the animal kingdom, which makes the walrus population very vulnerable to depletion.
Clams are the principal food of walruses.
They grub the clams from the sea bottom with their snouts or blow them loose with a jet of water, then suck the clams from their shells. This intensive tilling releases nutrients into the water column, provides food for scavengers such as starfish, and increases the patchiness of the bottom. The detailed impact on the ecology of bottom communities is unknown, but walruses clearly rank with such animals as beaver and sea otters, who have large effects on the biological communities they inhabit. Relationship with People Walruses harvest the resources of the sea floor and bring this concentrated bounty to the surface. In turn, walruses have been harvested by the Native peoples of Beringia since time immemorial.