What is taxonomy?
Northern elephant seals are in the family Phocidae. They have short, coarse grey or brown fur and a very thick blubber layer that insulates them from cold water.
Adult males are larger than females and can weigh up to 5,000 pounds. Females can weigh up to 1,700 pounds. Adult males have a ‘chest shield' that develops with age to protect them from injury when they fight with other males for breeding territories. The chest shield is pink and is formed from keratinized skin. Males also develop a probosicis with age.
Once each year, northern elephant seals molt. An epidermal molt is a unique characteristic of elephant seals and monk seals. Once a year the animals come ashore and shed their fur and the first layer of skin (or epidermis). The skin and fur come off in sheets as new skin and fur replace old. When the molt is finished, the animals have silver fur. Between the molting and breeding seasons, northern elephant seals remain at sea for 6 to 8 months, traveling thousands of miles and spending 86% of their time submerged.
- Northern elephant seal bulls have a big floppy nose, called a "proboscis"!
- The male northern elephant seal is larger than the female and can weigh up to 5,000 pounds. The female can weigh up to 1,700 pounds.
- Northern elephant seals dive almost continuously for 6 to 8 months during their migrations. They dive to depths of 300 feet or deeper and most dives are 20 or 30 minutes long. The deepest dive recorded is more than 1,500 feet and the longest dive is almost 2 hours!
- Northern elephant seals are one of four species of seals that have an epidermal molt. Once each year, they shed the first layer of skin and their fur. The skin and fur come off in sheets as new skin and fur replace the old.
- Northern elephant seal pups will more than triple their weight in the first month of life!
- Northern elephant seals were once thought to be extinct, now there are more than 100,000!
- The northern elephant seal is the only mammal known to make two long distance migrations in a year. They travel from their breeding colonies in Mexico and California to Alaska or the north Pacific Ocean to feed and then return to their breeding colonies to molt 2 to 6 months after breeding. After they molt they travel back to their feeding areas and return again to their breeding colonies to breed 6 months later. They may travel up to 21,000 miles in a year, the longest migration known for any mammal.
What should I know about Northern elephant seals?
- Where do Northern elephant seals live?
- How many Northern elephant seals are there?
- How can I identify a Northern elephant seal?
- What do Northern elephant seals eat?
- How do Northern elephant seals have their young?
- How long do Northern elephant seals live? How do they die?
- Where can I find more information about Northern elephant seals?
Northern elephant seals breed on offshore islands from northern California to central Mexico. A few colonies have formed on the central California coast in recent years. Their feeding range extends from Mexico to the Gulf of Alaska and far offshore.
The estimate of the worlds population of northern elephant seals is 127,000. There are about 101,000 off the California coast during breeding season and 26,000 off the Mexican coast. It is believed that only 100 remained in 1900.
Northern elephant seals are the largest pinnipeds in the northern hemisphere. Northern elephant seals are dark gray to brown. The males can weigh over 5,000 pounds and up to 16 feet long. The females can weigh 2,000 pounds and be up to 10 feet long. The prominent nose is very noticeable, with the males being much larger than the females. , with the males are darker gray than the females.
Northern elephant seals have a varied diet that they get from very deep dives. The diet includes shark, flatfish, ratfish, crab, squid, and octopus!
Adult males and females aggregate at the breeding colonies from December through February each year. Males establish territories and females aggregate in the territories. Each pregnant female gives birth to a single pup. Northern elephant seal pups are black at birth and may weigh up to 65 pounds. Pups molt the black coat and replace it with a silver coat similar to the adults about a month after birth. The female nurses the pup for about a month and the pups may triple their weight during the nursing period. The female weans the pup by abruptly leaving the colony and the pup. The weaned pups remain at the colony for a month or more after they are weaned and then leave the colony to learn to feed on their own.
The Northern elephant seal can live to be 22 years old.
Elephant seals have no land predators but great white sharks and killer whales prey on elephant seals. Environmental events such as El Ñino may cause high mortality of pups because of high tides that wash the pups to sea before they can swim.
- Marine Mammal Laboratory Library
- Seal Conservation Society
- University of Michigan - Animal Diversity Web
- The Marine Mammal Center
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