Northern fur seal (Alaskan fur seal)
The Northern fur seal, also known as the Alaskan fur seal, is a marine mammal found in the cold waters of the northern Pacific Ocean. Characterized by their sharp snouts and robust bodies, these seals are well adapted to their frigid environment, featuring a thick layer of blubber and dense underfur that insulates them. Adult males can reach lengths of up to seven feet and weigh as much as 600 pounds, while females are smaller, averaging five feet and weighing around 110 pounds. Their coloration varies, with females and young males typically displaying a silver-gray top and reddish-brown underside, while adult males are darker and possess distinctive manes.
Northern fur seals are carnivorous, primarily feeding on squid and various fish, and they require substantial daily intake to maintain their weight, especially during their growth periods. Their breeding season occurs from June to July, particularly at the Pribilof Islands, where large gatherings take place. Conservation efforts have helped increase their population after significant declines due to historical hunting practices. Although the species is recovering, it remains classified as vulnerable, facing threats from natural predators and environmental changes. With a lifespan of 25 to 30 years, these seals have a relatively long reproductive maturity age of around eight years.
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Northern fur seal (Alaskan fur seal)
Northern fur seals are furry sea mammals that live in the freezing cold waters of the northern Pacific Ocean. They are also called Alaskan fur seals.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Otariidae
Genus: Callorhinus
Species: Ursinus
Northern fur seals have sharp snouts, round bodies, and abundant underfur which helps to protect them from the freezing waters where they live. When they are wet their coats appear dark or almost black, but they can be many different shades when they are dry. Females of all ages, and young males, are usually silver-gray on top and reddish brown below, with lighter colored chests. Adult males have heavy manes and darker bodies, often black or dark brown, with short muzzles. Males can be up to five times larger than females. They can be as long as seven feet (two meters) and weigh up to 600 pounds (270 kilograms). Females usually measure up to five feet (1 1/2 meters) and weigh up to 110 pounds (50 kilograms). Northern fur seals have a layer of fatty tissue, called blubber, located right under their skin. This fat is used to keep the animals warm in colder waters and as a storage place for food.
Northern fur seals are carnivores, or meat-eaters. The food of fur seals varies depending on location, but often includes squid, herring, walleye pollock, and lantern fish. Young fur seals under the age of four need to eat about fourteen percent of their overall body weight in food each day to maintain their weight.
Fur seal pups are sometimes eaten by steller sea lions, or leopard seals. Other predators include killer whales and large sharks. Between 1786 and 1867, two and a half million fur seals were killed by hunters at the Pribilof Islands for their skins, fur, and blubber. The North Pacific Fur Seal Convention in 1911 banned open-sea sealing and saved the fur seal from extinction. The hunting of seals, however, continued into the late 1980s. Thanks to continuous conservation efforts, the northern fur seal is increasing its population numbers but remains a vulnerable species.
The fur seals' breeding grounds are very lively places from June to July. At their peak, the breeding of fur seals at Pribilof Islands was thought to be the largest gathering of large mammals anywhere in the world.
Fur seals are very active on land and in water. A male will gallop across a rocky beach in pursuit of a rival. On broken ground, a fur seal can progress faster than a man can run. Often the males will fight with each other for mates. Successful breeding bulls (males) have harems, or many female mates. The gestation period (duration of pregnancy) is one year. Eight days after the cow (female) has her pup, the baby seal, she will mate again, then depart to sea on a feeding trip. The cow, female seal, nurses the pup for about four weeks. After being weaned in three to four months, the pups will take to the sea in groups. The weaning for fur seals is shorter than for other seals so that they can protect themselves from predators. Northern fur seals are ready to mate when they are around eight years old.
Northern fur seals have a life span of 25 to 30 years.
Bibliography
Sackler, Rebecca. “ADW: Callorhinus Ursinus: Information.” Animal Diversity Web, 2012, animaldiversity.org/accounts/Callorhinus‗ursinus. Accessed 2 May 2024.
Thiessen, Mirko. “Northern Fur Seal - Facts, Diet, Habitat, & Pictures on Animalia.bio.” Animalia, 2024, animalia.bio/northern-fur-seal. Accessed 2 May 2024.