When you walk along a trail overlooking the numerous pocket beaches of Point Reyes, you may catch a glimpse of shy harbor seals (Phoca vitulina). They often haul out along the Pacific Coast from the Bering Sea to Baja California, sometimes in large numbers at established colony sites. Harbor seals are curious animals when in the water, and often lift their heads out of the water to look around. Sometimes when they see a person walking on the shore or kayaking, they follow at a distance of as close as 15–45 meters (50–150 feet) in the bays and estuaries of the park.
Harbor seals are residents of Point Reyes and so they may be sighted year-round both on land and in the nearshore waters. Some seals also migrate annually up to 800 km (500 miles) during the winter months to other foraging areas, and then return to Point Reyes to breed and molt their fur. Point Reyes has the largest population of harbor seals in California, excluding the Channel Islands, with twenty percent of state's harbor seals living or breeding within the park's boundaries. Select colonies at Point Reyes have been monitored since 1976, and have increased as the population has recovered with protection provided by the Marine Mammal Protection Act of 1972.
Harbor seals, and other pinnipeds, usually haul out in large groups onshore at traditional sites such as Point Reyes Headland. Their habit of hauling onto land to rest, give birth and nurse their young, and warm themselves in the sun provides nature enthusiasts a chance for an excellent wildlife sighting, but also makes the harbor seal vulnerable to disturbance. Harbor seals are shy animals whose habits are easily disrupted by the presence of humans on land. We recommend that visitors stay around 90 meters (300 feet) away from seals resting onshore.
How to Identify Harbor Seals
Harbor seals and elephant seals are in the Family Phocidae (the earless seals) so unlike sea lions and fur seals, they do not have external ear flaps on the head, just a small hole where their ear is. Harbor seals and elephant seals also are unable to rotate their pelvis, and so they drag their body inchworm fashion around on land, on beaches, or other nearshore substrates that have a low slope. Sea lions, in contrast, can rotate their pelvis forward and walk on all four limbs, enabling them to use steep, rocky shoreline habitat unavailable to harbor seals. Harbor seals also differ from sea lions in their smaller size and lighter color. When in water, harbor seals propel themselves with their hind flippers in a sculling motion, and steer with their front flippers, whereas sea lions and fur seals propel themselves with their fore-flippers, like wings.
What Do Harbor Seals Eat?
What eats harbor seals?
Rarely, male elephant seals have been documented killing harbor seals in California at harbor seal colonies such as Jenner. This elephant seal behavior is very unusual, and the male seals do not appear to interact or haul out with other elephant seals. Instead, they haul out at harbor seal colonies.
Why Harbor Seals Haul Out
All pinnipeds give birth on land, and that is one fact that distinguishes them from cetaceans, another group of marine mammals. Harbor seals give birth between March and June on tidal sandbars, rocky reefs and pocket beaches. They can give birth on areas which are inundated at high tide because harbor seal pups, unlike most pinniped species, can swim at birth. During the pupping season, mother seals will spend more time onshore nursing pups and resting, for an average of around 10–12 hours per day. The mother harbor seal stays with the pup almost continuously and rarely leaves the pup alone onshore. Mothers can take their pups with them when they go swimming and feeding because pups are adept swimmers.
A mother caresses and nuzzles its baby pup constantly, and for four to six weeks nurses it with her rich milk. The 48% fat content of milk makes the pup gain weight rapidly, and by around 30 days they are weaned. Pups weigh around 11 kg (25 lbs) at birth but when they are weaned they may weigh as much as 22 kg (50 lbs).
During the breeding season, male seals hold territories in the waters adjacent to where females haul out on shore, called maritory. Females are receptive to mating around when the pups are weaned and mating occurs in the water. Male seals will protect their maritory from other males and engage in stylized fighting during the breeding season.
Shortly after the pups are weaned, the seals begin their annual molt of their sea worn fur. The fur sheds much like a dog and the seals turn a luminous color with new fur. The molt period begins around mid-June and extends through July. During this time, seals will spend more time resting onshore because it is energetically taxing. Also, studies have shown that hair follicles grow faster in onshore than in the water. Seals can stay onshore resting for an average of 12 hours per day during the molt compared to around 7 hours per day during fall-winter months.
Harbor Seals Vulnerable to Disturbance
March through July, the pupping and molting seasons, is an especially vulnerable time for harbor seals. While hiking along the shores of the Pacific during these months, you may come across a seal pup alone on the beach. It is most likely not abandoned. The mother is probably in the water nearby feeding. However, if a mother is repeatedly disturbed on a site with her pup, she may decide to abandon her pup for the safety of the water, so please be sure to stay well away from any seals you see.
How You Can Help
Please take care NOT to make your presence known--either visually or audibly--when you come across an individual or a group of harbor seals when you are on land or on the water. Seals may flee into the water immediately when they hear or see a human. This flight disrupts their resting, can cause mother-pup separations and may endanger their health. If you see the seals raise their heads in a startle response, immediately back away so that they do not feel threatened.
Maintain a minimum distance of 90 m (300 feet) from any marine mammal in the water or on the shore to prevent a disturbance.
Avoid areas closed to visitors during the breeding season, from March 1 through June 30. Drakes Estero and the mouth to Drakes Estero are closed to boating, canoeing, and kayaking. Double Point and the western end of Limantour Spit are closed to all visitor access. Tomales Point is a harbor seal pupping area, but is not closed. Please use care not to disturb the animals at these places and keep a distance of 90 m (300 feet) away. Ask at visitor centers for a map indicating closed areas.
If you see an animal (adult or pup) that you think is in distress, do not touch or approach it. Contact a park ranger and give the exact location and a description of the animal, making note of its behavior, color, size (length and girth) and any particular markings or tags.
Contact the nearest National Seashore ranger first:
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.
Check out our Seasonal Harbor Seal updates to learn the latest news.
Even more information can be found on sfnps.org's Harbor Seals web pages.
Protecting Marine Mammals
Any human action that causes a change in the behavior of a marine mammal is considered harassment.
Watch the Elephants, Seals, and Lions, Oh My! video to learn how to differentiate harbor seals from other pinnipeds. Produced on October 7, 2012. 3:52 minutes.
Listen to the What's in a Seal? podcast. Produced on July 17, 2009. 6:28 minutes (3,044 KB mp3)