One of the best features of Point Reyes National Seashore is 80+ miles of undeveloped coastline and adjacent waters that support protected habitat, breeding grounds, and migration routes for a variety of marine mammals including the Harbor seal (Phoca vitulina). With an estimated 7,000 individuals, Point Reyes National Seashore easily boasts the largest concentration of harbor seals in the State of California.
Commonly referred to as "sea calves," or "sea dogs," harbor seals are considered true seals, with no ear tufts and no elongated fore flippers like sea lions. This smaller seal species typically breeds and feeds in the same area throughout the year. They generally do not live longer than thirty years and females tend to outlive males, though both genders incur their highest mortality rate during the first few months after birth. Male and female harbor seals are of similar coloration and size with a length of 5 feet and weight of up to 250 lbs. Their coat (pelage) color is typically a light beige with dark spots although some individuals have a reversed pattern of mostly black or dark brown with white spots. Occasionally a "red coat" harbor seal may be seen. The red pelage coloration may result from deposits of precipitated iron oxide on the hair. In water, harbor seals use their hind flippers for propulsion, while on land their method of locomotion is a caterpillar-like undulation utilizing their fore flippers for momentum.
Harbor seals may inhabit shallow areas of estuaries, rivers, and places where sandbars, beaches, or rocks are uncovered at low tide. Harbor seals use a variety of sites to rest or "haul-out" along coastal and inland waters to get warm and conserve energy. They prefer gently sloped beaches and low-lying flat spots since unlike their cousin the sea lion, a seal is unable to rotate its hind flippers underneath its body for greater locomotion on land. Harbor seals are carinovores, but are known to be opportunistic feeders. Their diet varies from one area to another and throughout the year depending on prey availability, and includes a wide variety of fishes and cephalopods. They generally feed close to shore or in shallow waters, and may feed at specific or preferred sites on a regular basis.
At Point Reyes, pups are generally born in the spring, which the park observes with special closures March 1 - June 30. Females produce one pup per year, beginning at age four or five. The majority of pups are born at protected haul-out sites but a female may give birth anywhere with easy access to the water's edge. Pups are precocial at birth, capable of swimming and following their mother into the water immediately after birth. Nursing pups remain with their mothers for about 4 to 6 weeks and then are weaned to forage and survive on their own. A nursing pup may triple its birth weight by the time it is weaned and uses its stored fat reserves as it learns to feed on its own. Pups frequently call to their mother with a sheep-like "m-a-a-a"; adults make a variety of sounds including grunts, growls and barks.
Common threats to the species include predation, disease, changes in food supply, disturbance to haul-out sites by commercial and recreational use, ship or boat injuries, and environmental changes such as rising sea levels. Marine mammals, including harbor seals, are protected under the Marine Mammal Protection Act of 1972 which makes it illegal to hunt, harm or harass any species of marine mammal in U.S. waters. Please stay at least 200 feet away from any marine mammal. If you find an injured or sick seal, you may report it to the Marine Mammal Center by calling 415-289-SEAL (7325), but please do not approach it.
Best Time to View
Year-round, breeding season March 1 - June 30
Best Place to View
Depending on the season and weather, park visitors have an opportunity see these majestic mammals from various overlooks, but make sure to bring binoculars for the best viewing opportunity. Since harbor seals are residents of Point Reyes they may be sighted year-round both on land and in the ocean surrounding the park. The best viewing sites are Sunset Beach, Drake's Estero, Bolinas Lagoon and by kayak along Tomales Bay. Avoid areas closed to visitors during the breeding season (March 1 - June 30) including areas in Drakes Estero and on Tomales Bay.
Become a Harbor Seal Monitoring Docent at Point Reyes National Seashore. Volunteers monitor the population of harbor seals in spring and summer. The data that they gather help scientists follow trends in the population, assess their health, identify disturbances to the harbor seals and protect, and preserve this valuable resource. Contact Sarah Codde at (415) 464.5210 or send an email.
Harbor Seal Resources