Overview of the Northern Elephant Seal
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Male elephant seal Female elephant seal Elephant seal pup
- The northern elephant seal, also known as Mirounga angustirostris, is the largest of the pinnipeds. The word pinniped comes from Latin, of course, pinna meaning featherand ped meaning foot.
- The northern elephant seal belongs to a group called true seals, also known as earless seals as their ears are not visible. All true seals are members of the family Phocidae and are sometimes called crawling seals. Having streamlined bodies makes the phocids highly specialized for aquatic life. Their sleekness is aided by having retractable nipples, internal testicles, and a penis which lies in an internal sheath.
- The elephant seal is so named because of the adult male's extended and inflatable proboscis or trunk, which resembles an elephant's trunk.
- Adult male elephant seals can reach up to 16 feet in length and weigh up to 5,000+ lbs. Females, on the other hand, are quite a bit smaller, growing up to about 9 feet in length and tipping the scales at about 1.500 lbs. This disparity in size is called sexual dimorphism. Pups are usually 3-4 feet at birth and weigh about 60 pounds.
- Elephant seals propel themselves through the water by using lateral motion with their back flippers. One flipper will close, while the other sweeps through the water in a back and forth motion. In the water, their side/fore flippers are primarily used for steering, whereas on land, the side flippers are largely used to help the seals pull their heavy bodies upright and forward. On land, they propel themselves forward by heaving the front part of their bodies up and lunging forward. For the most part, they perform just two to three forward lunges before lying down again to recoup their strength. However, don't be deceived. When motivated, these enormous mammals can "race" across several yards of beach without stopping.
- To keep themselves warm, elephant seals are able to divert blood-flow to their smooth layer of blubber, which lies under their external skin. This ability helps regulate and control their body temperature.
- Because the elephant seal's respiratory and circulatory systems are adapted to allow diving to considerable depths, they spend much more time under water than they do at the surface. Air is dispelled from the lungs before diving, and throughout the 20-70 minutes the elephant seal is under water, the oxygen they require is obtained from their blood and tissues. Because elephant seals possess blood that is rich in hemoglobin and tissues rich in myoglobin, their oxygen storing abilities are quite remarkable.
- Many northern elephant seals call the central coast of California home for the portions of the year when they haul out to give birth, mate, or molt. The rest of the time, according to scientists, they're out foraging for food, sometimes traveling as far north as Alaska.
- What do elephant seals eat ? As far as scientists know, they eat mainly a variety of squid, octopi, small shark, rays, crustaceans, and some fish such as Pacific whiting, ratfish or spiny dogfish. Some scientists believe that they might even enrich their diet with seaweed every now and then.
- What preys on elephant seals ? Scientists believe that there are only two predators of these seals today, namely the great white shark and the killer whale or orca.
- As of 2009, scientists believe there are 200,000+ elephant seals in the colonies along the California coast.
