Elephant Seal

filed under | marinelife

Share/Bookmark

Elephant seals take their name from 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 16 ft (5 m) and a weight of 6,000 lb (2,700 kg) and are much larger than the cows, which typically measure about 10 ft (3 m) and 1,900 lb (900 kg). The largest known bull elephant seal weighed 11,000 lb (5,000 kg) and measured 22.5 ft (6.9 m) in length. This makes the elephant seal the largest member of the order Carnivora. Elephant seals spend upwards of 80 percent of their lives in the ocean. They can hold their breath for more than 100 minutes — longer than any other non-cetacean mammal. Elephant seals dive to 1550 m beneath the ocean's surface (the deepest recorded dive of an Elephant Seal is 2,388 metres (7,835 ft) by a Southern Elephant Seal). The average depth of their dives is about 300 to 600 metres (2,000 ft), typically for around 20 min for females and 60 min (1 hour) for males, as they search for their favorite foods, which are skates, rays, squid, octopuses, eels, penguin (Southerns only), and small sharks. Their stomachs also often contain gastroliths. While excellent swimmers, they are also capable of rapid movement on land, where they have a higher speed than the average human when moving over sand dunes. Elephant seals are shielded from extreme cold by their blubber, more so than by fur. The animals' hair and outer layers of skin molt periodically. The skin 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". While the molt is taking place the bulls cease fighting with one another as there are not breeding harems and females in estrous to protect. Northern males 'haul out' in August, and females in May–June. Female elephant seals have an average life expectancy of about 23 years, and can give birth starting at the age of 4–5. Males reach maturity at five years, but generally do not 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 20 years. Only 1 in 10 males will become an alpha or beta male. [READ THE REST OF THIS ARTICLE]





wikisnap.com is not affiliated with or endorsed by wikipedia. wikipedia and the wikipedia globe are registered trademarks of wikipedia.org.
article content reproduced in compliance with wikipedia's copyright policy and gnu free documentation license
view our privacy policy and terms of service here