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Elephant SealsKingdom = AnimaliaPhylum= ChordataClass = MammaliaOrder = CarnivoraSuborder = PinnipediaFamily = Phocidae
There are two different species of Elephant Seal, Northern and Southern. They do not differ much at all other than in their size and where they live. Male elephant seals are called bulls nd have an average life expectancy of 20 years. The females have a life expectancy of 23 years. During the 19th century, Elephant seals were close to extinction because they were hunted for their oil. By 1892, there were only 50 to 100 seals left and the only colony left was off the coast of Baja California. In 1922, the first laws to protect the seals were instated by the Mexican government. Since then, number have increased and there are approximately 160,000 northern elephant seals today.



Physiology
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Most elephant seals grow to 16 feet and weigh about 6,600 pounds. To compare their large size, cows only grow to be 10 feet and weigh about 2,000 pounds so Elephant Seal are significantly larger. Despite their large size, they are capable to rapid movement in the ocean and on land. Elephant seals have fore flippers, back flippers, and a tail. The fore flippers each have five webbed fingers with nails are used for either scratching or climbing rocks. The webbed hind flippers are used for swimming and help the seals balance when they are at an upright position. Lastly, the tail of the Elephant seal is found between the two back flippers.



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They get their name, Elephant Seal, from the large proboscis of the adult bulls(males). This proboscis, or trunk, of the seal is used as a way of communicating and as a rebreather. This trunk can grow up to two feet long, and the nostrils can be opened and closed independently of one another. During mating season, the bulls use the their trunks to produce a loud roaring sound to fend off other seals who attempt to take their territory. The proboscis is used as a rebreather because it is filled with cavities designed to conserve body moisture. These cavities reabsorb the moisture from the animals' exhalations and this is vital during mating season because the males do not leave the beach to feed.

In order to stay warm in the waters, especially the Southern seals in the Antarctic waters, they have blubber and fur. The blubber is several inches thick and is made up of lipid and collagen. It covers the whole body and

is attached to the muscles and skeleton of the seal. 50 percent of a bull’s body weight consists of blubber and is important for managing their body temperature. It is also an important part of their food source because
during their mating and birthing season on land, the seals do not eat at all and have a built-in food storage that they use for energy. The fur on the seal does not act as an insulator but rather a layer to protect the blubber. The fine hair of the fur also helps water drag in the ocean.


During the spring and summer months, Elephant seals do something called molting. This molt period is when they replace old skin and hair. Most animals do this year round,but elephants seals so it all at once.
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An Elephant Seal molting during the summer



Northern and Southern Elephant Seals

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yellow areas are where elephant seals are found.

Northern Elephant seals are commonly found off the Pacific coast of United States, Canada and Mexico. A popular spotting of this species is found off the tip of Vancouver
Island. These aquatic animals prefer offshore islands rather than mainland when it comes to breeding season.

Southern Elephant seals, who prefer to live in sub- Antarctic and Antarctic waters because they are rich with marine founds that they enjoy such as fish and squid. Like the Northern elephant seal, they spend their time breeding on land, but in the winter they are in these brutally cold waters. Other places in the Southern hemisphere that this species is found are off the coast of New Zealand and South Africa, islands such as South Georgia, and the fourth largest seal colony in the world, Pennisua Valdes on Argentina. Another significant characteristic that differs the two species is the size of the Southern Elephant Seal. They are notebly larger than the average seal at a size of over 20 feet long and weight 8,800 pounds.



Life in the Ocean

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Feeding patterns of male and female elephant seals

Elephant seals spend 80 percent of their lives in the ocean (8-10 months a year). They can hold their breath up to 100 minutes and dive downwards as far as 1550 meters. On
average, seals dive between 300 and 600 meters to find food. A female seal usually dives for 20 minutes and the males can be under there for up to an hour. They have a large volume of blood so they are able to hold their breathe and keep oxygen for a long amount of time during feeding. In addition, they have large sinuses in their abdomen. This is useful for holding blood and store oxygen in their muscles. With more red blood cells than most aquatic animals, Elephant seals are able to stay under water for longer amount
of time and dive further.

Northern and Southern Elephant seals eat skates, rays, squid, octopuses, and eels. Only Southern seals eat penguins because they live in the arctic waters. Females do not eat during mating or birthing season and males do not eat for 3 months when they are on land as well. Because of the prolonged time without food, the seals but eat a substantial amount when at sea and store in in their blubber. When the males and females return to sea, they tend to stay away from one another and travel with their own sex. Males tend to stay more northern than the females when searching for food. More information is known about the seals when they are on land during molting and reproduction because during foraging, the seals are too spread out for scientists to study in groups. To eat their food, Elephant Seals have eight pairs of flat canine teeth on the upper and lower jaws. Since most of their diet can be swallowed whole, they use the teeth to hold the prey in place. If the food is larger than they can handle, they thrash around until the prey is broken down and small enough to swallow.



Birth
The Elephant seal breeding season begins in December and this is when they return to the beaches they were born at. This also happens to be the same beaches they molt at during the summer. A month before the females arrive, the bulls come on shore and engage in battles to establish dominance and territories. The juvenile males also arrive at this time to perform “mock battles” These fights are visible to humans when they can see bulls fighting with threats, vocalizations, and lunging. A common threat is when a male raises his front flippers and vocalizes with his proboscis. When two alpha males are in the same area and do not agree on territory, the fighting becomes physical. One eventually gives up before bloodshed, but there can be damage to one another. The areas of seals that humans can see on the beach are known as "rookeries"




In late December, the females arrive and form “harems”. These harems are groups of females that are territory and property of one bull. Harems can reach to 50 females
each. Three to six days after the arrival, the females give birth to one or two pups each. The first sign of birth of a pup on land is when a flock of seagulls come to eat the afterbirth. The female and the pup then "roar" together to exclaim and announce the birth.
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A bull and female mating
The females then nurse for 25 to 28 days after giving birth. Their milk, which is 55% fat, causes the pup to grow from 75 pounds at birth to up to 350 pounds. These weaners then leave the beach with their mothers after they have mated again. The super weaners are the pips that can weigh up to 600 pounds. When is comes time to return to the water, some of the pups have gained too much weight that they cannot get to the water. They then wait there to shed some of the weight before entering the ocean. About 24 days after the females give birth, the bulls and females mate again. Although they mate, the fertilized egg is notimplanted for about 2 months because scientists believe that the female’s body is too weak to nourish the egg.






Sources
"Elephant Seals." California State Parks. Web. 29 Nov. 2011. <http://www.parks.ca.gov/?page_id=1115>.

"Elephant Seal." Wikipedia, the Free Encyclopedia. Web. 29 Nov. 2011. <http://en.wikipedia.org/wiki/Elephant_seal>

FES Home. Web. 29 Nov. 2011. <http://www.elephantseal.org/>.

"Elephant Seals, Elephant Seal Pictures, Elephant Seal Facts - National Geographic."Animals - Animal Pictures - Wild Animal Facts - Nat Geo Wild - National Geographic. Web. 29 Nov. 2011. <http://animals.nationalgeographic.com/animals/mammals/elephant-seal/>.

"Elephant Seals: Feeding." MarineBio.net. Web. 29 Nov. 2011. <http://www.marinebio.net/marinescience/05nekton/esfeed.htm>.

"Adult Male Elephant Seals Fighting for Territory - YouTube." YouTube - Broadcast Yourself. Web. 29 Nov. 2011. <http://www.youtube.com/watch?v=rfLVR4a6Exg>.

"Wild Kingdom- Elephant Seal Birth - YouTube." YouTube - Broadcast Yourself. Web. 29 Nov. 2011. <http://www.youtube.com/watch?v=rZgfCC2-Wd0>.