Elephant seal
| Elephant Seal | |
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| File:Elephant seal.jpg | |
| Southern elephant seal, Mirounga leonina | |
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| Genus: | Mirounga
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Elephant seals are large, oceangoing mammals in the genus Mirounga, in the earless seal family (Phocidae). There are two species: the Northern Elephant Seal, M. angustirostris, and the Southern Elephant Seal, M. leonina. Both were hunted to the brink of extinction by the end of the nineteenth century, but numbers have since recovered. The Northern Elephant Seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the U.S. and Mexico. The Southern Elephant Seal is found in the southern hemisphere on islands such as South Georgia, Macquarie Island, and on the coasts of New Zealand, South Africa, and Argentina in the Peninsula Valdés, which is the fourth largest elephant seal colony in the world and the only growing population.
Appearance
Elephant seals take their name from the great size of their bodies and the large proboscis of the adult males (bulls) which resembles an elephant's trunk. The bull's proboscis is used in producing extraordinarily loud roaring noises, especially during the mating season. More importantly, however, the nose acts as a sort of rebreather, filled with cavities designed to reabsorb moisture from the animals' exhalations. This is important during the mating season when the male seals rarely leave the beach to feed, and therefore must conserve body moisture, as they have no incoming source of water. Bulls of both the northern elephant seal and the southern elephant seal reach a length of 18 ft (5.5 m) and a weight of 5,000 lb (2,270 kg), and are much larger than the cows, which typically measure about 10 ft (3 m) and 1,430 lb (650 kg). The largest known bull elephant seal weighed 5000 kg (11,000 lb) and measured 6.9 m (22.5 ft) in length. This makes the elephant seal the largest member of the order Carnivora.
Ecology
Elephant seals spend up to 80 percent of their lives in the ocean. They can hold their breath for over 80 minutes—longer than any other non-cetacean mammal. Furthermore, elephant seals possess the ability to dive to 1500 meters beneath the ocean's surface. The average depth of their dives is about 300 to 600 meters, as they search for their favorite foods, which are skates, rays, squid, octopuses, eels, and small sharks. Their stomachs also often contain gastroliths. While excellent swimmers, they are even more surprising on land, where they have a higher velocity than the average human when moving over sand dunes.
Elephant seals are shielded from extreme cold by their blubber, more than by fur. The skin on top of this blubber and its hair molts periodically. It has to be re-grown by blood vessels reaching through the blubber. When molting occurs, the seal is susceptible to the cold, and must rest on land, in a safe place called a "haul-out." The type of molt which an elephant seal undergoes is a catastrophic molt. While this is taking place, the bulls actually cease fighting with one another.
Elephant seals have extra spaces in their abdomens called sinuses where they can store extra blood.[1]
Lifespan
Female elephant seals have an average life expectancy of about 20 years, and can give birth starting at the age of 3–4. Males reach maturity at five years, but generally don't achieve alpha status until the age of 8, with the prime breeding years being between ages 9 and 12. The average life expectancy of a male elephant seal is 14 years.
See also
External links
- http://www.elephantseal.org/
- Elephant Seal Research Group - http://www.eleseal.it
Media
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Northern Elephant seal in California -
Elephant seals hauled out on a beach -
Vagrant adolescent male Elephant seal resting up on Campbell Island, New Zealand -
Males fighting, Point Reyes, CA, US -
Molting elephant seals, Año Nuevo State Park, California -
Molting elephant seals, Año Nuevo State Park, California
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| Elephant seals mating |
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HELLO EVERYONE I'M AN ELEPHANT SEAL CALLED FRED!