HARBOR SEAL
Phoca vitulina
meaning of Latin name: calf-like seal

DESCRIPTION: Harbor seals have spotted coats in a variety of shades from silver-gray to black or dark brown. They reach five to six feet (1.7-1.9 m) in length and weigh up to 300 pounds (140 kg). Males are slightly larger than females. They are true or crawling seals, having no external ear flaps. True seals have small flippers and must move on land by flopping along on their bellies. In San Francisco Bay, many harbor seals are fully or partially reddish in color. This may be caused by an accumulation of trace elements such as iron or selenium in the ocean or a change in the hair follicle.

RANGE/HABITAT: Harbor seals are found north of the equator in both the Atlantic and Pacific Oceans. In the northeast Pacific, they range from Alaska to Baja California, Mexico. They favor near-shore coastal waters and are often seen at sandy beaches, mudflats, bays, and estuaries.

MATING AND BREEDING: In California, harbor seal pups are born in March and April and weigh about 30 pounds at birth. If born prematurely, harbor seals retain a whitish lanugo coat (which is usually lost before birth). A pup can swim at birth, and will sometimes ride on its mother's back when tired. Pups make a bleating noise that sounds like "maaaa." After about four weeks, the pups are weaned. Adult females usually mate and give birth every year. They may live 25 to 30 years.

BEHAVIOR: Harbor seals spend about half their time on land and half in water, and they sometimes sleep in the water. They can dive to 1,500 feet (457 m) for up to 40 minutes, although their average dive lasts three to seven minutes and is typically shallow. They are opportunistic feeders, eating sole, flounder, sculpin, hake, cod, herring, octopus, and squid.

While harbor seals swim safely in the surf, they will often curiously watch humans walking on beaches. However, they are wary of people while on land, and will rush into the water if approached too closely or disturbed. In fact, if disturbed too often, they have been known to abandon favorite haul-out sites or their pups.

STATUS: The total harbor seal population in the eastern north Pacific is estimated to be 330,000, and in California the estimated population was 40,000 in 1997. They are usually found in small groups, but sometimes occur in numbers of up to 500.

AT THE MARINE MAMMAL CENTER: From approximately mid-February through the end of June, The Marine Mammal Center's rescue and rehabilitation work is mainly focused around the care of harbor seal and elephant seal pups. Each year people find harbor seal pups on shore and pick them up, thinking the pups have been abandoned. Usually they are not abandoned; the mothers are just out hunting or watching nearby. This problem has caused many seals to be unnecessarily orphaned. These pups are then at further risk because they are unable to get needed antibodies from their mothers' milk, making them more susceptible to diseases. When they are being cared for at The Marine Mammal Center they are kept in an area away from the other animals so they do not catch other diseases. If you see a harbor seal pup alone on a beach, remember to call The Marine Mammal Center at 415. 289.7325 to find out what to do.

May be reprinted for scientific and educational purposes

Revised 1/01

Learn more about the following:

Northern Elephant Seal
California Sea Lion
Steller Sea Lion
Northern Fur Seal
Guadalupe Fur Seal

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