Behavior

Most phocid species are gregarious during an annual molting period, when they haul out on land or ice to shed their hair and acquire a new coat. Many species form colonies during an annual breeding period, with species like elephant seals forming large dense harems of over a hundred females and a few males, all lying in contact with one another, to dispersed male-female pairs of hooded or crab-eater seals (Lo-bodon carcimphagus) a half mile (0.8 km) or more apart on floating ice pans.

Males and females of many species migrate from breeding areas to separate areas used for foraging. In some cases these migrations are associated with seasonal changes in ice patterns. Other species remain in the vicinity of the seasonal breeding areas for feeding or disperse in a more random pattern rather than migrating.

Otariid seals are better adapted to locomotion on land than are phocids. Otariids can rotate their rear flippers underneath their body and "walk" on four flippers. Phocids must crawl on their ventral surface like a caterpillar or swish their rear end from side to side for locomotion on land, likely incurring higher energy costs for movement on land than otariids. While swimming, otariids use their foreflippers in an oar-like fashion, whereas phocids use their rear flippers, thrusting them from side to side for propulsion. (Illustration by Jacqueline Mahannah)

Otariid seals are better adapted to locomotion on land than are phocids. Otariids can rotate their rear flippers underneath their body and "walk" on four flippers. Phocids must crawl on their ventral surface like a caterpillar or swish their rear end from side to side for locomotion on land, likely incurring higher energy costs for movement on land than otariids. While swimming, otariids use their foreflippers in an oar-like fashion, whereas phocids use their rear flippers, thrusting them from side to side for propulsion. (Illustration by Jacqueline Mahannah)

Researchers are only beginning to learn more details about foraging tactics as a result of a few studies that have attached cameras to free-living seals to record the behavior of the seals during foraging. One such study of harbor seals shows that some males use a tactic of digging in the bottom substrate for species that bury themselves in sand while others find and follow schools of fish, picking off individual fish that leave the school and go to the bottom to avoid the seal.

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