Fur seals are a group of marine mammals belonging to the Otariidae family, including sea lions. They are known for their thick, luxurious fur, external ear flaps, and strong swimming abilities. Several species of fur seals are classified into two genera: Arctocephalus (southern fur seals) and Callorhinus (northern fur seal).

Northern Fur Seal (Callorhinus ursinus): Males can reach up to 2.1 metres (7 feet) and weigh around 270 kilograms (600 pounds), while females are smaller, about 1.3 metres (4 feet) and 50 kilograms (110 pounds).

Southern Fur Seals (Arctocephalus spp.): Size varies by species, but males generally weigh 2–5 times as much as females.

Fur seals have dense underfur with long guard hairs that provide insulation and a plush appearance. Their colouration ranges from grey to brown, with some species showing lighter underbellies. They have external ear flaps (pinnae) and long, muscular front flippers for swimming.

Fur seals are highly social, especially during breeding seasons, forming large colonies called rookeries.

They are agile swimmers, often travelling long distances in search of food and are capable of foraging at great depths.

Many fur seal populations were heavily hunted for their fur in the 18th and 19th centuries, leading to drastic declines.