The Juan Fernández fur seal (Arctocephalus philippii) is the second smallest of the fur seals, after the Galápagos fur seal. They are found only on the Pacific Coast of South America, more specifically on the Juan Fernández Islands and the Desventuradas Islands. Much is still unknown about this species. Scientists do not yet know the average lifespan of this species, or the diet and behavior of males outside the breeding season.

Description

The Juan Fernandez fur seal is part of the group of eared seals. Fur seals in general have thick insulating fur that protects the skin from cold water, they have small ear flaps on the side of their head, and they hold their weight on their front flippers which are also used for land locomotion. Fur seals are different from true seals because they have external ear flaps, but also true seals use their chest for support and movement, and fur seals walk on their front flippers.

The Juan Fernandez fur seal is the second smallest fur seal, second only to the Galápagos fur seal. Their bodies are short and robust with brown pelage. Both the fore flippers and the hind flippers are relatively short, and the hind flippers have fleshy tips on the digits. Females are lighter brown and average and long. Males are significantly larger and average and in length. Males have thicker necks than females and have generally darker brown pelage. Male seals have golden-tipped thick guard hairs on the back of the head, neck, and shoulders.

History

The Juan Fernández fur seal was discovered, and named, by Juan Fernández in the mid-1500s. Once the seal was discovered the population was decimated by over hunting for the fur trade. It was believed that the Juan Fernández fur seal was extinct until a small group of 200 was found on the Juan Fernández islands in the 1960s. Now it is estimated that over 12,000 individuals exist today.

The resulting classification by Peters became the subject of a long-running scientific controversy. Hermann Burmeister compared drawings and the written description of the species with specimens at the La Plata Museum and concluded in 1866 that it was not a new species but a Phoca porcina that was described by the Jesuit Juan Ignacio Molina many years ago. This seal is polygynous, meaning that one male breeds with multiple females. Pups are born between November and December and are weaned off the mother's milk at 10 months of age. Mothers stay with the pups for about a week and then they leave to mate again and forage. Pups are born with soft black fur that fades to light brown within the first few years. However, during this time, the pups' immune systems are not as highly-functioning as adults and can be prone to infection from intestinal parasites that lead to fatal infections. In the early 1990s, there were 60 pups discovered dead from hookworm infections, and also the presence of heavy metal ions were found in their systems. Such loss decimated the population and they are still recovering now.

See also

References

  • ARKive - images and movies of the Juan Fernández fur seal (Arctocephalus philippii)