Elephant seals spend most of their life at sea, but starting in late December, individuals begin to come on shore one by one. Males arrive first. Fourteen to sixteen feet long and weighing up to 2 1/2 tons, they engage in small skirmishes and violent battles to establish dominance and for the right to settle in the center of the harem and mate with all its females.

Females give birth to a single 75-pound pup 3 to 6 days after they come on shore, then they gather in large harems. They nurse their young for 28 days, then abandon the pups (who now weigh up to 350 pounds) to return to the sea. By March, most of the adults are gone and the pups, called "weaners" must learn how to swim, find food and survive on their own.

Most animals shed hair year-around, but elephant seals do it abruptly. They return to the shore during the spring and summer to molt. The rest of the year they are at sea, where they spend up to 90% of their time under water, diving for 20 minutes at a time to a depth of 2,000 feet searching for food.