Northern fur seals back in California after 170 years


This video says about itself:

See these nothern fur seals up close filmed in HD quality!

The Northern Fur Seal (Callorhinus ursinus) is an eared seal found along the north Pacific Ocean, the Bering Sea and the Sea of Okhotsk. It is the largest member of the fur seal subfamily (Arctocephalinae) and the only species in the genus Callorhinus.

Northern fur seals have extreme sexual dimorphism, with males being 30–40% longer and more than 4.5 times heavier than adult females. The head is foreshortened in both sexes because of the very short down-curved muzzle, and small nose, which extends slightly beyond the mouth in females and moderately in males. The pelage is thick and luxuriant, with a dense underfur that is a creamy color. The underfur is obscured by the longer guard hairs, although it is partially-visible when the animals are wet. Features of both fore and hind flippers are unique and diagnostic of the species. Fur is absent on the top of the fored flippers and there is an abrupt “clean shaven line” across the wrist where the fur ends. The hind flippers are proportionately the longest in any otariid because of extremely long, cartilaginous extensions on all of the toes. There are small claws on digits 2–4, well back from the flap-like end of each digit. The ear pinnae are long and conspicuous, and naked of dark fur at the tips in older animals. The mystacial vibrissae can be very long, and regularly extend beyond the ears. Adults have all white vibrissae, juveniles and subadults have a mixture of white and black vibrissae, including some that have dark bases and white ends, and pups and yearlings have all-black vibrissae. The eyes are proportionately large and conspicuous, especially on females, subadults, and juveniles.

Adult males are stocky in build, and have an enlarged neck that is thick and wide. A mane of coarse longer guard hairs extends from the top of the head to the shoulders and covers the nape, neck, chest, and upper back. While the skull of adult males is large and robust for their overall size, the head appears short because of the combination of a short muzzle, and the back of the head behind the ear pinnae being obscured by the enlarged neck. Adult males have an abrupt forehead formed by the elevation of the crown from development of the sagittal crest, and thicker fur of the mane on the top of the head.

Canine teeth are much longer and have a greater diameter in adult males than those found on adult females, and this relationship holds to a lesser extent at all ages.

Adult females, subadults and juveniles, are moderate in build. It is difficult to distinguish the sexes until about age 5. The body is modest in size and the neck, chest, and shoulders are sized in proportion with the torso. Adult females and subadults have more complex and variable coloration than adult males. They are dark-silver-gray to charcoal above. The flanks, chest, sides, and underside of the neck, often forming a chevron pattern in this area, are cream to tan with rusty tones. There are variable cream to rust-colored areas on the sides and top of the muzzle, chin, and as a “brush stroke” running backwards under the eye. In contrast, adult males are medium gray to black, or reddish to dark brown all over. The mane can have variable amounts of silver-gray or yellowish tinting on the guard hairs. Pups are blackish at birth, with variable oval areas of buff on the sides, in the axillary area, and on the chin and sides of the muzzle. After 3–4 months, pups molt to the color of adult females and subadults.

Males can be as large as 2.1 m and 270 kg. Females can be up to 1.5 m and 50 kg or more. Newborns weigh 5.4–6 kg, and are 60–65 cm long.

The teeth are haplodont, i.e. sharp, conical and mostly single-rooted, as is common with carnivorous marine mammals adapted to tearing fish flesh. As with most Caniforms, the upper canines are prominent.

The northern fur seal is found in the north Pacific — its southernmost reach is a line that runs roughly from the southern tip of Japan to the southern tip of the Baja California peninsula, the Sea of Okhotsk and the Bering Sea.

From the San Francisco Chronicle in the USA:

Rare fur seals reclaim place on Farallon Islands

Animals fled 1834 slaughter; now they’re back and breeding

Glen Martin, Chronicle Environment Writer

Monday, September 11, 2006

A marine mammal that disappeared from California’s North Coast more than 170 years ago has returned in force to the Farallon Islands.

The Farallones once supported hundreds of thousands of breeding northern fur seals — big marine predators with luxuriant pelts.

Their thick, soft fur proved their undoing: In 1834, sealers slaughtered about 200,000 of the animals, delivering their pelts to Fort Ross in what is now Sonoma County.

The rest of the seals fled, abandoning their rookeries for more than a century and a half.

A few started returning in the early 1970s, but this year their numbers surged — an indication of the islands’ enduring vitality and proof that a sensitive species can revive under favorable circumstances.

“We’re ecstatic to see any marine mammal recovery, but it’s especially gratifying when you’re talking about a sensitive species like northern fur seals,” said Clyde Morris, manager of the Don Edwards San Francisco Bay National Wildlife Refuge.

“Their comeback is probably due to the high protection from human intrusion the Farallones receive.” …

Adam Brown, a PRBO marine biologist stationed at the Farallones, said six fur seals lived on the refuge in 1998. That increased slowly through 2004, when there were 38, Brown said.

“There were 90 in 2005, and last week we counted 188,” he said.

If the rate of increase continues to accelerate, Brown said, there could be up to 50,000 fur seals on the Farallones in less than a decade.

“It’s unclear if there are the habitat and prey base to support that many, but those kinds of numbers are at least possible,” he said.

Paradoxically, that sort of success could be a problem.

If the big, voracious fur seals return to the Farallones in anything approaching their original numbers, it could harm other mammals and birds, experts say.

Of particular concern, Sydeman said, are Cassin’s auklets.

The rare seabirds nest in the same kind of habitat fur seals prefer for their rookeries.

“Cassin’s auklets have suffered almost complete breeding failures for two consecutive years at the Farallones,” Sydeman said, noting the lack of nesting success was likely due to excessively warm water temperatures and inadequate plankton production.

“Any additional stress during the breeding season could have serious repercussions for them.”

Brown agreed that such concerns are justified.

“Any time you introduce a top predator into a system, you can expect changes,” he said.

“Right now, they’re not directly encroaching on the bird colonies, but that time probably isn’t very far away.

That said, it’s wonderful to watch this unfold. New pinniped colonies aren’t established every day.”

Unlike other West Coast pinnipeds such as harbor seals and sea lions, northern fur seals are pelagic by inclination, meaning they spend most of their lives drifting with the ocean currents. …

Perhaps a million northern fur seals range the North Pacific, which includes California waters.

The World Conservation Union, a group that keeps track of threatened species worldwide, considers the seal a vulnerable species at risk of extinction in the future.

Most of the world’s northern fur seals breed on the Pribilof Islands in the Bering Sea.

Indeed, some of the seals now inhabiting the Farallones migrated from the Pribilofs, Brown said.

“So far, we have counted nine seals, all females, that have Pribilof tags,” he said.

Smaller colonies are also found at Bogoslof Island in the Aleutian chain, and San Miguel Island off Santa Barbara.

Colonies of relatively modest size are also established on several islands in Russian territorial waters.

Though the global fur seal population may seem substantial, say biologists, their numbers are down drastically from the 1970s.

This year, about 850,000 adult and juvenile fur seals were on the Pribilof Islands — a 46 percent decline from the mid-1970s, Sydeman said.

Increased Bering Sea Ice Explains Prehistoric Fur Seal Rookeries: here.

Steller’s sea lions on camera: here.

Steller’s sea lions population decline: here.

New Zealand: Conservation groups have come together to put up reward money for any information that will result in an arrest and conviction of the person responsible for clubbing to death 23 fur seals: here.

5 thoughts on “Northern fur seals back in California after 170 years

  1. Pingback: USA: killer whale attacks great white shark | Dear Kitty. Some blog

  2. Pingback: Alaska’s Rat Island, a bird island again | Dear Kitty. Some blog

  3. Pingback: How Alaskan fur seal pups migrate | Dear Kitty. Some blog

  4. Pingback: Scandinavian prehistoric barley farming, earlier than thought | Dear Kitty. Some blog

  5. Pingback: Farallon Islands wildlife returning | Dear Kitty. Some blog

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.