Elephant Seals (genus Mirounga)

A couple of weeks ago I was talking to a friend and she mentioned that elephant seals were about five meters long. Now, I’ve seen harbour seals and sea lions at the Vancouver aquarium, and even though male seal lions are huge, none of them looked to be five meters long. So a five meter long pinniped seemed unlikely. My concept of five meters stems solely from the middle diving board at the UBC swimming pool, which I only once ever managed to jump down from (I had just as much trouble with the three meter, and even some trouble with the one for a while). So maybe my fear has made five meters into a much bigger distance than it actually is, but still, a five meter long seal is impressive.

It turns out there are two species of elephant seal, the northern elephant seal and the southern elephant seal. Northern seals inhabit the western coast of Mexico, the US, and Canada, while the southern seals live in and around Antarctica. Northern elephant seals grow up to five meters, as my friend correctly said, but southern seals get even bigger. They are the largest pinnipeds, and the largest living Carnivores. The record for a southern elephant seal was a bull that measured 6.85 meters, and weighed an estimated 5000 kilograms. That’s just ridiculous.

An elephant seal showing off its great nose

An elephant seal showing off its great nose

Aside from their immense size, elephant seals are named for their large nose. Only male seals have this enormous proboscis, and the nose is used for multiple purposes, including challenging other males to fights. Males compete for females during the breeding season, and will often roar at each other before a clash. These noises are so loud they can be heard several miles away. The noses also help elephant seals retain moisture, which is particularly helpful during the breeding season, when males go without food (and thus a source of water) for months.

Elephant seals have a very rough breeding season. After horrible bloody battles in which giant males slam necks together and try to gore one another with their teeth, they have to go for months without food or water. They cannot leave their hard-won harem lest a rival male sneak up and steal their females. So the males wait on the beach, keeping a careful eye on dozens of females, while living on nothing but their blubber. It doesn’t sound like much fun to me.

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Two bull elephant seal fighting, with bloody consequences

When they aren’t starving themselves to get some action, elephant seals are prolific swimmers, and their entire body is adapted to such a lifestyle. They can stay underwater for over a hundred minutes, and dive up to 2,388 meters. A large amount of blood in their bodies helps hold enough oxygen for their long-distance dives. As well, they have big sinuses in their abdomens which hold blood, and have the ability to store oxygen in their muscles.

Fat is extremely important to elephant seals; not only does it save males from starving during the breeding season but also helps keep the seals warm. Thus, baby elephant seals have to put on a lot of fat very fast in order to be ready for the cold ocean. And all that fat has to come from mom. Cow’s milk has about 3.5% fat, human milk about 4%. Elephant seal milk rises to over 50% fat. Talk about heavy cream!

Elephant seals are pretty amazing creatures; everything these guys do seems to be in the extreme. Which is a really, really good way to get the attention of a blogger in need of an interesting animal! So you earned this post, elephant seal, you truly did.

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2 thoughts on “Elephant Seals (genus Mirounga)

  1. Pingback: Walrus (Odobenus rosmarus) | Our Wild World

  2. Pingback: Leopard Seal (Hydrurga leptonyx) | Our Wild World

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