Callorhinus ursinus

• Male Northern Fur Seals reach sexual maturity at 3–4 years old, but they can only reproduce from 7–8 years old.
• Female Northern Fur Seals often suffer serious injuries or die due to fighting over females, as males grab them by the back of the neck, flippers, or sides.
• Male northern fur seals are much larger than females. The maximum body length of males reaches 2.2 meters, and their weight can reach up to 320 kg.
• Northern Fur Seals often forcibly keep females on their territory, especially in cases of isolated harems.
• The breeding grounds of the Northern Fur Seal are limited to several islands, including the Commander Islands, Medny Island, the Kuril Islands, and the Pribilof Islands.