Fur Seals: Characteristics, Behavior, Species | Sea Life, Islands and Oceania

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FUR SEALS

fur seal species, From Animal Spot animalspot.net

Fur seals are sea lions not seals. They have forward-pointing back limbs, which allows them to get around on land, and have soft dense fur next to their skin. Coarse guard hairs provide a dense outer coat. Males remain in polar regions the year round but females migrate to warmer climates to give birth to their young. One of the main that distinguished sea lions and fur seals is that the latter has thick underfur.

The Fur seals thick layer of fur grows underneath coarse protective hair. But this hair does little to keep them warm when they dive deep in the water. To keep warm in deep seawater and on land seals and sea lions need blubber. Sea lions and fur seals have relatively thin layers of blubber but have more hair.

Fur seals were once extensively hunted for their furs. The fur is waterproof and very warm for the seals on land and at in surface waters. Their fur loses it warmth when the animal dives because under great pressure the water squeezes out the relatively warm air between the hairs.

Websites and Resources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se; Encyclopedia of Life eol.org; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures

Southern Fur Seals

Southern fur seals include seven distinct species, of all of which live south of the Equator except the Guadalupe fur seal, The South African and Australian are the largest. The primary thing that differentiates them is geography, although some breed on the beaches in the. same island groups of the southern oceans.

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Antarctic fur seal
Fur Seal Species: Common name (Scientific name), Subspecies, Numbers
Antarctic fur seal (Arctocephalus gazella), 700,000-1,000,000
Galápagos fur seal (Arctocephalus galapagoensis), Endangered, 10,000

Guadalupe fur seal (Arctocephalus townsendi), 10,000
New Zealand fur Seal (Arctocephalus forsteri), 100,000
Subantarctic fur seal (Arctocephalus tropicalis), 200,000.

Brown fur seal (Arctocephalus pusillus), 1,060,000: Subspecies: Cape fur seal (A. p. pusillus), 1,000,000; Tasmanian fur seal (A. p. doriferus), 60,000
South American fur seal (Arctocephalus australis), 99,000
Unnamed Peruvian fur seal,10,500

Falkland Island fur seal (A. a. gracilis), unrecognized by IUCN, 109,500
Juan Fernández fur seal (Arctocephalus philippii), 16,000. They are found only on the Pacific Coast of South America, more specifically on the Juan Fernández Islands and the Desventuradas Islands.

South American Fur Seals

South American fur seals (Scientific name: Arctocephalus australis) inhabit rocky shores along the coasts of Uruguay, Argentina, Chile and Peru. They are most numerous on the Atlantic side of South America and can be found on Uruguay islands and the Falkland Islands. Secluded places with few human disturbances and are safer for breeding. South American fur seals are found as far north as central Peru. They have been sighted as far off as 600 kilometers from the coast. [Source: Amelia DelGreco, Animal Diversity Web (ADW) /=]

South American fur seal

South American fur seals spend approximately equal time on land and at sea. When they dive they typically do so to depths of 40 to 170 meters (130 to 560 feet). Breeding periods are spent on the shores of Peru, Argentina, Uruguay and the Falkland islands. When its not the breeding season, they are usually in the ocean. When on land, they prefer rocky areas to shield them from the sun. They are able to move quite easily on land and are able to climb steep slopes. In the wild, these fur seals live between 12 and 30 years.

South American fur seals are nocturnal hunters. They feed on anchovies, shrimp, lobster, squid and krill. Where they live plays a big part in what they eat. In Peru and Uruguay they feed primarily on anchovies. Those living closer to Brazil shores hunt for shrimp. Those in Chile favor krill, particularly lobster krill. Fur seals can dive up to 170 meters and can stay underwater for seven minutes per dive. If the females are caring for young on shore, they will spend a couple days at sea, then come back for a few days to care for their pup.

South American fur seals are hunted by the South American sea lions, orcas, sharks, and humans. Other threats them include climate change and overfishing. These seals were hunted from 1515 to 1979 in Uruguay and Chile for their fur to make clothes skin to make leather and oil to light lanterns. They are no longer hunted commercially, but are still often poached, often for king crab bait. In 1997 the seals were harmed by an oil spill that covered about 5,000 square kilometers. An estimated 6,000 seals were killed. During El Nino years, food becomes scarce for the seals on the Pacific side of South America. An El Nino In Peru 2012, wiped out 80 percent of the females and pups. In Uruguay, the population is healthy and growing. South American fur seals are not endangered. They are designated as a species of least concern on the International Union for Conservation of Nature (IUCN) Red List and have no special status on Trade in Endangered Species (CITES).

South American Fur Seal Physical Characteristics

range of the South American fur seal

South American fur seals range in length from 1.4 to 1.9 meters (4.6 to 6.2 feet) and range in weight from 40 to 200 kilograms (90 to 440 pounds). Sexual dimorphism (differences between males and females) is significant. Males are much larger than females. Sexes are colored and patterned differently These seals are endothermic (use their metabolism to generate heat and regulate body temperature independent of the temperatures around them). [Source: Amelia DelGreco, Animal Diversity Web (ADW) /=]

Males can get up to three times larger than females. Females can reach up to 1.4 meters (4.6 feet) in length, whereas males can reach up to 1.9 meters 6.2 feet). Females weighing 50 kilograms (110 pounds) are considered large, but males can get up to 200 kilograms (440 pounds). Female seals are either dark brown or a dark gray on their backs, lighter in color on the nottom of their bodies. Male coloration is similar but can be darker. Juvenile males begin to have guard hairs around their face, from the top of their heads to about the shoulder area. When they become adults, the mane of guard hair is frosted with lighter gray coloring.

Adult seals have a stockier body than other fur seals and have a longer snout. The fins are also longer and narrower than other fur seals. South American fur seals have 20 upper teeth and 16 lower teeth. They have long front flippers to help them move around on the rocky shores. The fins of other fur seal tend to be more paddle like than those of South American fur seals.

South American Fur Seal Behavior and Communication

South American fur seals are nocturnal (active at night), motile (move around as opposed to being stationary), sedentary (remain in the same area), social (associates with others of its species; forms social groups), and have dominance hierarchies (ranking systems or pecking orders among members of a long-term social group, where dominance status affects access to resources or mates). In terms of home range, male seals compete for territory during breeding season along the shore. The most dominate male tend to have larger territories. [Source: Amelia DelGreco, Animal Diversity Web (ADW) /=]

South American fur seal in the Falklands Islands

South American fur seals live together in rookeries along the shore. They often fish in groups and fur seals do move around. They spend most of their time in the water swimming, diving and searching for food. During the breeding season they live on land. Seals pick areas to breed that are rocky and provide shade. Males compete physically for territories and females . Each male competes for an area, and the most dominate males generally obtains the largest and best positioned area.

South American fur seals communicate with vision, touch and sound and sense using vision, touch, sound and chemicals usually detected with smell. They employ several vocalizations. noises. Mothers and their pup have a special calls that are individual to each pair. Studies indicate that pups only recognize their mother's voice. When a mother returns to her rookery after foraging in the ocean for a couple days, she needs to be able to find her pup among the crowd.

South American Fur Seal Mating and Reproduction

South American fur seals: 1) are viviparous, meaning they give birth to live young that developed in the body of the mother; 2) engage in delayed implantation (a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months); and 3) employ in embryonic diapause (temporary suspension of development of the embryo).[Source: Amelia DelGreco, Animal Diversity Web (ADW) /=]

South American fur seals breed once a year shortly after the females give birth. The breeding season is between October and December. The number of offspring is one. The gestation period ranges from eight to 12 months.On average females reach sexual maturity at age three years. On average males reach sexual maturity at seven years.

South American fur seals are polygynous (males having more than one female as a mate at one time). Males fights and compete for certain areas along the shore between October and December to establish territories for themselves and females in their harem. Dominant males claim the most females and the largest territory. The ratio of male to female South American fur seals is greater than that of any other mammal, implying that each male has more females on average than any other polygynous mammal. Seven to ten days after giving birth, the female will mate with a male. Embryonic diapause (temporary suspension of development of the embryo) lasts between three and four months.

South American Fur Seal Parenting and Offspring

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fur seal pup
South American fur seal young are precocial. This means they are relatively well-developed when born. Parental care is provided by females. During the pre-birth and pre-weaning stages provisioning and protecting is done by females.

Newborns weigh between 3.5 and 5.5 kilograms (7.7 and 13 pounds) and measure 60 to 65 centimeters (2 to 2.2 feet) in length. When they are first born, pups are black. As they grow and molt they become lighter. They molt three to four months after birth. [Source: Amelia DelGreco, Animal Diversity Web (ADW) /=]

Females give birth during per breeding season. Pups are weaned between six and 12 months. They may nurse for up to three years. In this extreme case, mothers nurse two pups at the same time. Males reach sexual maturity around the age of seven, but many of them don’t actually mate until they are eight years of age. This may be the result of competition required to earn territory and females.

Female seals give birth and feed pups until they are able to feed on their own. After pups are born mothers alternates between days in the water foraging for food and days on land caring for their young. Often times, the survival of the pup relies on how crowded the shoreline is with seals. When the mother is gone foraging, if the shore is too crowded, the young pup can get trampled by other female seals or get lost and starve. El Nino years often result in a lack of prey fish for the mothers to catch and the many pups die of starvation.

Guadalupe Fur Seals

Guadalupe fur seals (Scientific name: Arctocephalus townsendi) live in the waters off southern California and the Pacific coast of Mexico. During the breeding season, they are found in coastal rocky habitats and caves. Little is known about their whereabouts during the non-breeding season. Females weigh around 50 kilograms (110 pounds) and are about 1.5 meters (five feet long). Males weigh about 180 kilograms (400 pounds0 and are 2.2 meters (seven feet) long. Their lifespan is about 20 years. [Source: NOAA]

Guadalupe fur seal

The breeding grounds of Guadalupe fur seals are almost entirely on Guadalupe Island, off the Pacific coast of Mexico. There are small populations off Baja California on San Benito Archipelago and off southern California at San Miguel Island. Guadalupe fur seals generally do not migrate, although they have been documented traveling great distances from their breeding grounds. They are only species of southern fur seals that occurs north of the equator. From archeological findings Guadalupe fur seals were historically found as far north as the northwest Washington coast.

Threats include entanglement and incidental hooking on (longlines) in commercial and recreational fishing gear, oil spills, coastal development and military activities Commercial sealers heavily hunted Guadalupe fur seals in the 1700s to the 1800s until they were thought to be extinct in the early 1900s. Dr. Hubbs and Dr. Bartholomew from the University of California rediscovered them breeding in a cave on Guadalupe Island in 1954.

The Guadalupe fur seal population has continued to increase from the small remnant group on Guadalupe Island due to protection by the Mexican Government. Guadalupe fur seals are listed as threatened under the Endangered Species Act and depleted under the Marine Mammal Protection Act. The Guadalupe fur seal population has been growing steadily since 1955.Based on surveys conducted between 2008 and 2010 there are approximately 20,000 of these fur seals.

Guadalupe Fur Seal Characteristics, Behavior, Feeding and Reproduction

Guadalupe fur seals have narrow, flat heads with pointed, narrow, long snouts. Their fore-flippers are broad, with some hair, reaching past their wrists and forming a "V" on the foreflipper. Their coloration is dark brown. Adult males have tan or yellow hairs on the back of the mane. Adult males are considerably longer and larger-bodied than adult females. [Source: NOAA]

range of the Guadalupe fur seal

Guadalupe fur seals are generally solitary, are thought to be non-social animals when at sea. They primarily feed at night on coastal and pelagic squid, and small pelagic fish (such as, mackerel,sardine, and lanternfish) by diving to average depths of 30 meters (65 feet) with maximum depths of about 76 meters (250 feet), They rest in the water with their heads below water and their hind-flippers jutting out. NOAA]

Guadalupe fur seals' breeding season extends from June through August. Adult males return to the colonies during early June. They set up territories that they defend through aggression and vocalizations when challenged or threatened by other males. Breeding Guadalupe males are polygamous and may mate with up to 12 females during a single breeding season. Adult females arrive to the colonies in early June, giving birth a few days later. Pups are born from early June through early July, with a peak in late. Pups are born from early June through early July, with a peak in late June. An adult female will mate about a week after giving birth to her pup. Weaning occurs around nine months.

Northern Fur Seals

Northern fur seals (Scientific name: Callorhinus ursinus) range over a large area from the Bering Sea in the east to the Japanese islands of Hokkaido and Honshu in the west. Also known as the Alaska or Proibilof fur seal, northern fur seals feed on fish and squid and hunt at night. They have very sensitive whiskers which they use to track prey. They in turn are fed on by sharks and killer whales. Sometimes pups are taken by foxes on land. There are around 650,000 of them. It was once estimated that there were more than a million of them.

Northern fur seals get their name from their fur, which looks black when wet but is brownish gray or reddish brown on males and silvery-gray with a white patch on females. Their hair is densely packed at 60,000 hairs per square centimeter, forming a waterproof coat and layer of insulation that allows the animal to thrive in cold water and deep sea environments. Their blood contains 3½ times the hemoglobin of humans.

Northern fur seal

Northern fur seals are members of the "eared seal" family (Otariidae). They spend most of the year in the ocean. Males can live up to 18 years, while females can live up to 27 years. Weaned pups typically spend nearly two years away before returning to their breeding colonies. Northern fur seals primarily use open ocean for foraging and rocky beaches for resting and reproduction. [Source: NOAA]

Northern fur seals often sleep in the open sea. They sleep unihemispherically, which means that one hemisphere of the brain sleeps while the other is awake. Dominant males form harems with 20 or 30 members and occasionally up to 100. They copulate with females for a month without eating and lose about 25 percent of their body weight. Sometimes females mate again within 48 hours of giving birth.

Northern fur seals have been hunted by Russians, Americans, Canadians and Japanese. for their fur and body parts which are regarded as having medicinal properties. One Japanese shogun ate fur seal extracts for strength. Hunting them is a matter of considerable controversy. Images of baby fur seals being clubbed

Image Sources: Wikimedia Commons, NOAA

Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.

Last Updated June 2023