Northern Fur Seal

Callorhinus ursinus
Family: Otariidae
northern fur seal

Photo © Verena A. Gill


See a 3-D animation of a northern fur seal skull.

fur seal range map

Distribution/Migration: North Pacific. Long-distance seasonal migrants. Leave Alaska rookeries in October–November and remain offshore until March–June. Adult males overwinter in North Pacific, females and subadult males spend winter offshore from Southeast Alaska to California. Pink shows summer range, purple shows year-round range.

This web page is modified from the book Marine Mammals of Alaska by Kate Wynne, illustrated by Pieter Folkens, available at the Alaska Sea Grant Bookstore.

Marine Mammal Guide

SIZE: Average adult male 6.5 ft (2 m), 300–600 lbs. Average adult female 4.2 ft (1.3 m), 65–110 lbs. At birth 2 ft. (0.6m), 11–12 lbs.

BODY: Small eared seal with thick fur and disproportionately long hind flippers. Ears tightly rolled and appear to be located low on neck (lower than eye level). Head round with large eyes and short, conical snout. Adult males have thickened neck and pronounced furred crown.

COLOR: Silver-gray to brown, appear black when wet. Female and juveniles have tan chest and flanks. Whiskers black at birth and lighten with age until white by age 6–8 yrs.

BEHAVIOR: Inquisitive and mostly solitary at sea. Adults come ashore only briefly, congregate on rookeries annually to pup and breed. Dive up to 7 min to over 600 ft (180 m). Sleep with nose, one front, and both hind flippers above water ("jughandle" position) while at sea. Porpoising common.

HABITAT: Primarily pelagic (7–10 mos per yr). Use remote islands as rookeries (primarily Pribilofs, but also Bogoslof Island, Alaska, and San Miguel Island, California).

FOOD HABITS: Feed primarily at night on variety of schooling fish and squid to 10 in. Herring, capelin, pollock, and squid important in Alaska waters.

LIFE HISTORY: Sexually mature at 4–5 yrs. Females breed late June–July with dominant males that establish and defend territories. Single pups born late June–July after gestation of 11.8 mos. Lactation lasts 4 mos; pups suckle intermittently between females' foraging trips at sea (up to 250 mi from rookery).

STATUS AND HUMAN INTERACTIONS: Depleted. Approx 700,000 in east Pacific and declining. Regulated commercial harvest on Pribilofs 1911–1984. Current annual subsistence harvest <800 animals, mostly juvenile males. Debris entanglement, fishery interactions, predation, and climate change are potential threats.