Species: Callorhinus ursinus
Northern Fur Seal
Species
Encyclopedia of Puget Sound
Classification
Kingdom
Animalia
Phylum
Craniata
Class
Mammalia
Order
Carnivora
Family
Otariidae
Genus
Callorhinus
NatureServe
Classification
Other Global Common Names
otarie à fourrure du Nord
Informal Taxonomy
Animals, Vertebrates - Mammals - Carnivores
Formal Taxonomy
Animalia - Craniata - Mammalia - Carnivora - Otariidae - Callorhinus - for these seals.
Ecology and Life History
Short General Description
A fur seal.
Habitat Type Description
Marine
Migration
false - false - true - Males arrive in breeding areas in late May and early June, migrate south to winter range from early August to early October. Females and young migrate south beginning in October (e.g., see Ragen et al. 1995 for information on migration from St. Paul Island south through the Aleutian Islands), gone from Bering Sea by late November; begin returning north to rookeries in March (Reeves et al. 1992). San Miguel Island population probably stays in California waters all year.
Non-migrant
false
Locally Migrant
false
Food Comments
Feeds mostly on small schooling fishes and squids, including a wide variety of species in both groups. Occasionally eats birds. Feeds mostly at night. Adult males fast 1-2 months during breeding season. In the Pribilof Islands, lactating females forage usually within 160 km of rookery, occasionally up to 430 km away; feeding dives average about 68 m, sometimes exceed 200 m (Reeves et al. 1992).
Reproduction Comments
Females arrive at rookery mainly in June, with some arriving as late as early August. Pups are born 2-3 days after pregnant females arrive. Pupping peaks about July 15, usually ends about August 1. Mating occurs 4-7 days after single pup is born. In the Pribilofs, pups are weaned in October and November, about 125 days after birth; young go to sea soon afterward. Females sexually mature usually at 4-5 years, few males breed before they are 8-9 years old. In a given year, about 57% of adult females give birth. Few males breed in more than 2 seasons. Maximum longevity about 26 years. Male territory may contain from less than 10 to about 100 females.
Ecology Comments
Solitary or slightly gregarious at sea. <br><br>Large sharks, killer whales, and northern sea lions are the primary predators. Mortality rate is nearly 50% in first year; natural mortality averages 10-20% per year for 2-3-year-olds, 10-11% for mature females, and 32-38% for adult males (Reeves et al. 1992). <br><br>Some movement occurs among rookeries; immigrants from the Pribilof, Commander, and Robben islands contributed to growth of the San Miguel Island colony, and recent repopulation of the Kuril Islands evidently resulted from immigration of seals from western and eastern Bering Sea rookeries (Reeves et al. 1992).
Weight
270000
Conservation Status
NatureServe Global Status Rank
G3
Global Status Last Reviewed
2008-01-11
Global Status Last Changed
1996-11-18
Distribution
Conservation Status Map
<img src="http://www.natureserve.org/explorer/servlet/GetMapGif?CA.BC=__&US.AK=S2&US.CA=S1&US.OR=__" alt="Conservation Status Map" style="width: 475px; height: auto;" />
Global Range
Breeding range is mostly the eastern and western Bering Sea and Sea of Okhotsk; also the vicinity of San Miguel Island, California. Primary breeding sites are the Pribilof Islands (St. Paul and St. George) in the eastern Bering Sea and the Commander Islands in the western Bering Sea; smaller breeding rookeries are on Robben Island in the Sea of Okhotsk, on the Kuril Islands north of Japan, on Bogoslof Island in the eastern Aleutians, and on San Miguel Island (Adams Cove, Castle Rock) in southern California (Reeves et al. 1992). A few haul out seasonally on Southeast Farallon Island and (rarely) on San Nicolas Island, California (Reeves et al. 1992). In winter, the species ranges south to the Honshu coast, Japan, to California, and occasionally the Mexican coast in the eastern Pacific. Adult females range farther south in winter than do males, about which little is known regarding nonbreeding distribution (perhaps remain near the Aleutians).