Mammals · Carnivora · Otariidae

Northern Fur Seal

Callorhinus ursinus

Vulnerable

It faces a high risk of extinction in the wild over the medium term. See full glossary

The northern fur seal — known in Spanish as oso marino septentrional or lobo fino del norte — is an otariid of the North Pacific that spends most of the year on the open sea and comes ashore only to breed, in extremely dense colonies. More than half the world population breeds on the Pribilof Islands, in Alaska. Unlike the true seals, it does not depend on a thick layer of blubber but on an extraordinarily dense coat that traps an insulating layer of air, which made it the target of intensive fur hunting for two centuries.

Weight

30 kg – 270 kg

Size

1.3 m – 2.1 m

Lifespan

25 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Irregular activity

Active at irregular times, by day or night depending on circumstances.

Social structure

Colony

Lives in large concentrations, often for breeding reasons.

Sighting difficulty

Moderate

Fun facts

  • Its coat can hold some 46,000 hairs per square centimetre, one of the highest densities in the animal kingdom, exceeded only by the sea otter.
  • It spends up to three hundred days at a stretch at sea without setting foot on land, sleeping at the surface with one flipper out of the water.

Life cycle & biology

Skeleton type
Vertebrate - internal bony skeleton (mammal)
Habitat & environment
Open sea of the North Pacific; it breeds on remote islands such as the Pribilofs and the Commander Islands
Birth weight
5 - 6 kg
Size at birth
About 60-65 cm; born with a black coat
Sexual maturity
3 years
Gestation / incubation
7.9 months
Litter / clutch size
1.3 (average)

Sources consulted: https://es.wikipedia.org/wiki/Callorhinus_ursinus

Best time: From June to August on the Pribilof Islands and in Kamchatka, when the breeding colonies fill with territorial males.

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Related species

Other species in the catalogue with the most in common with Northern Fur Seal — same habitat, park, country, tags or family.

How to help

The northern fur seal is classified as vulnerable. Organizations such as UICN, WWF y Wildlife Conservation Society work specifically on its conservation and that of its habitat; looking into their programs is a good starting point if you want to get involved.

It's documented in 7 real protected areas — part of why protecting these places matters for its conservation.

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