The Northern Fur Seal was nearly hunted nearly to extinction at the turn of the 1900's for its fur. Their breeding grounds at the Pribilof Islands were leased to hunting companies. Since then, the government has intervened, now their numbers have increased greatly.

The Pribilof Islands host 2/3 of the world's population of Fur Seals during breeding season. Males arrive in early May and June to establish territories. They will defend these territories fiercely until the female seals arrive about 50 days later in mid June. As many as 100 females may be found in one territory but 20 to 60 is more common. Within two days of coming, they will most likely give birth to a single pup. They will stay and mate again within a week. Females will nurse the pups for up to four months.

The seals leave the Pribilof islands in November and December. By the end of December no animals are left. Young males and females can be found in the south by Mexico. Older animals stay in the Bering Sea during winter.

Here is a list of the population of fur seals at different places:

1,000,000 Pribilof Islands, St. George and St. Paul

50,000 Kuril Islands

55,000 Tyuleniy Island

225,000 Commander Island

5,000 Bogoslof Island

4,300 San Miguel