Cream patches are also noticeable on the sides and top of the muzzle, chin and under the eye. Adult males are dark brown to black with grey or yellowish guard hairs on the back of the mane, and the neck, chest and shoulders are enlarged. Northern fur seals have relatively small heads with short, pointed snouts. On warm days, the hind flippers can be seen waving above the water, dissipating heat. Northern fur seals are most likely to be seen alone or in pairs and spend quite a bit of time at the surface, asleep or grooming.
Males gather on the rookeries at breeding time to establish and def ined territories.
Breeding occurs on the Pribilof Islands from mid-June to August and approximately two weeks earlier in California. Pups are born black with lighter colouring on the belly and face. Mating occurs about one week after birth. Pups are nursed for about 4 months. Females, pups and juveniles migrate south from northern rookeries, remaining offshore along the continental shelf until they return the rookeries in March.