Fur Seal - Behavior and Ecology

Behavior and Ecology

Typically, fur seals gather during the summer months annually in large assemblages at specific beaches or rocky outcrops to give birth and breed. All species are polygynous, meaning dominant males reproduce with more than one female. For most species, total gestation lasts about 11.5 months, including a several-month period of delayed implantation of the embryo. While northern fur seal males aggressively select and defend the specific females in their harems, males of southern species of fur seals tend to protect spatial territories, and females are free to choose or switch their mates according to their own preference or social hierarchy. After several continuous days of nursing the newborn pups, females go on extended foraging trips that can last as long as a week, returning to the rookery to feed their pups until they are weaned. Males fast during the reproductive season, unwilling to leave their females or territories.

The remainder of the year, fur seals lead a largely pelagic existence in the open sea pursuing their prey wherever it is abundant and plentiful. Fur seals feed on moderately sized fish, squid and krill. Several species of the southern fur seal also have sea birds, especially penguins, as part of their diets. The fur seals themselves are preyed upon by sharks, orcas and occasionally by larger sea lions.

When fur seals were hunted in the late 18th and early 19th centuries, they hauled out on remote islands where there were no predators. The hunters reported being able to club the unwary animals to death one after another, making the hunt profitable even though the price per seal skin was low.