The elephant seal is a species of earless seal belonging to the Phocidae family. There are two species of such seals in the world: Mirounga angustirostris, the northern seal, and M. leonine, the southern seal. These are the largest seals and largest known Pinnipeds in the world.
This seal is the largest Pinniped, larger even than walruses. The southern seal is larger than its northern counterpart, with males typically reaching 5 meters in length and 3,000 kg. Some males are reported to grow 6 meters long and weigh in excess of 4,000 kg. The northern species is smaller, with typical weights of 2,500 kg and lengths of more than 4 meters. Cows are much smaller, with southern females measuring around 3 meters and weighing 900 kg. The name of the species comes from the proboscis of the males which resemble the trunk of an elephant.
The proboscis of the male is actually special apparatus which serves as a rebreather. It is a sinuous structure which has many cavities where extra moisture from exhaling can be drawn. This allows males to spend more time on land during the mating season, as they cannot restore their water reserves during that period of time.
These seals spend most of their lifetime in the ocean, with more than 80 percent in water. They can hold their breath for up to 100 minutes, although most females dive for 20 minutes and males for 60 minutes. Besides being able to hold their breath longer than any non-cetacean animal, the elephant seal is also a deep diver, with recorded dives at depths of 2,300 meters. The body of these seals is protected by a thick layer of blubber which shields them from the cold.
The northern species inhabits the Pacific coast of the North American continent, from Canada to the US and Mexico. The southern seal inhabits the southern hemisphere, from South Georgia to the coasts of New Zealand, South Africa, as well as the Valdes Peninsula of Argentina.
The diet of these seals generally consists of rays, skates, octopuses, squid, as well as fish such as small sharks, eels and some large fish.
These seals haul-out on beaches during the mating season. Males reach sexual maturity at 5 to 6 years but may start to breed starting from the age of 8. Elephant seal females reach sexual maturity at 3 to 4 years and they produce one of the fattest milk in the mammalian kingdom, with concentrations of milk fat of up to 50 percent.