Northern Fur Seal: CIC Exhibit

Northern Fur Seals

CIC Museum Research Document (Created 2/1/2026) Creative Commons photograph.

Far beyond Washington’s shoreline, vast herds of northern fur seals fill the air with barking calls as they begin one of the longest migrations of any marine mammal. Each year, they can travel up to 6,000 miles across the open Pacific, moving between remote breeding islands in Alaska and Russia and foraging grounds that stretch from Southern California to Japan. For most of their lives, these seals remain far from land, hunting in deep offshore waters. When they do appear along Washington’s coast, it is often due to powerful ocean forces, seasonal changes, or challenges at sea. Sightings in places like Grays Harbor offer a rare glimpse into life in the open ocean and the health of Pacific marine ecosystems.

Not Quite Seals

Northern fur seals (Callorhinus ursinus) are close genetic relatives of seals, sea lions, and walruses. Despite their name, they are not true seals. Northern fur seals belong to the family Otariidae, or the eared seals, while true seals are members of the Phocidae family, which lack external ear flaps. Fur seals are more closely related to sea lions, sharing key traits such as visible ear flaps, the ability to rotate their hind flippers forward to move on land, and a similar skeletal structure.

At Home in the Open Ocean

Northern fur seals are pelagic, meaning they spend the vast majority of their lives at sea. These marine mammals come ashore almost exclusively for breeding, pupping, resting, and molting — fasting while on land and returning to the sea to hunt intermittently. Adult fur seals typically spend over 300 days per year—about 80 % of their time—in the open ocean, returning to land mainly during the summer breeding season and for their annual molt.

Heavyweight Champions:

Northern fur seals exhibit extreme sexual dimorphism, meaning males and females differ greatly in size and appearance. Adult males can weigh three to four times more than females. During winter, males feed heavily on fish and cephalopods such as squid, building the energy reserves they will need for the breeding season.

Males are the first to arrive at the breeding islands, where they compete for and claim the best stretches of beach. Once established, a male northern fur seal will aggressively defend his territory and a harem of females for the duration of the breeding season. This can last around six weeks, during which males typically do not eat at all. By the end of this intense period of fasting, male northern fur seals  may lose up to one-third of their body weight.

Life Begins on a Crowded Shore

Each summer, female northern fur seals return to remote breeding islands such as the Pribilof Islands in the Bering Sea, often coming back to the same sites where they were born. Most female northern fur seals give birth to a single pup within a day or two of arriving on land. Newborn pups remain in constant contact with their mothers for about 8–10 days, learning her unique call and scent before she must return to the sea to feed.

Over the next three to four months, mothers alternate trips to the open ocean to forage with visits ashore to nurse their pups. During these absences, pups remain on land and rely entirely on the energy stored from their mother’s rich milk.

Rookeries—crowded breeding colonies—are risky places for newborn fur seals. Pups weigh only 10–14 pounds, while large, territorial adult males can weigh 350–600 pounds. To avoid injury, pups quickly learn to seek shelter beneath or between rocks.

Once weaned, young fur seals leave the rookery and head to sea. Many juveniles remain in the open ocean for nearly two years before returning to land, spending this early stage of life almost entirely at sea.

Pitiful Pearl

Pitiful Pearl is a young northern fur seal on display here at the CIC. Based on her size, she was likely just 4–6 months old at the time of her stranding. Freshly weaned from her mother’s milk, she had recently begun the journey south to forage on her own. At this stage, young fur seals must quickly learn to hunt and survive in the open ocean. She was found deceased in the fall of 2011, around the time when northern fur seals leave their summer breeding grounds. Her story, while a sad one, is a powerful reminder of the challenges these animals face in the wild. Northern fur seals have only about a 50% chance of surviving from weaning at four months old to their first year of life.

The Importance of Sustainable Harvesting

Ancestors of the Quileute and Quinault nations historically hunted northern fur seals from dugout canoes during the fur seal migrations along the Pacific coast. These communities practiced sustainable hunting, taking only what was needed and only during the seals’ annual migrations. By the mid-1800s, however, they likely witnessed the rapid decline of northern fur seal populations. Thousands of miles away, Russian sealing stations at the Farallon Islands near San Francisco decimated local fur seal populations between 1812 and 1840. By exploiting the northern fur seal’s foraging grounds, Russian traders contributed to dramatic declines in the global population almost driving them to extinction. Reducing the population from an estimated 2-3 million individuals to about 216,000–300,000 individuals in just a few decades.

Road to Recovery and Current Conservation

The recovery of the northern fur seal was made possible through human intervention like the North Pacific Fur Seal Convention of 1911 — one of the first international treaties regulating commercial hunting — and further protections from the 1972 Marine Mammal Protection Act.

Today, the Quileute and Quinault nations do not hunt northern fur seals. However, the loss of this historic resource of food and pelts stands as a reminder of the ecological consequences that occur when sustainable practices are ignored.

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Sources

1. Maniscalco, John M. “The effects of birth weight and maternal care on survival of juvenile Steller sea lions (Eumetopias jubatus).” PloS one vol. 9,5 e96328. 7 May. 2014, doi:10.1371/journal.pone.0096328
2. Allen, Sarah G., Joseph Mortenson, and Sophie Webb. “Northern Fur Seal.” Field Guide to Marine Mammals of the Pacific Coast: Baja, California, Oregon, Washington, British Columbia. Berkeley: University of California, 2011. 442-54. Print.