Elephant Seal Profile
When we think of the deepest diving animals, we think of the true heavyweights like the Sperm whale, or perhaps the Cuvier’s beaked whales, who likely surpass even the largest toothed whale in their abilities.
But coming up right behind these record-holders is an animal that doesn’t look like it should be competing in anything athletic at all. And yet, the elephant seal holds a record that is very nearly as impressive as the cetaceans.
Elephant Seal Facts Overview
| Habitat: | Antarctic and sub-Antarctic waters |
| Location: | Eastern Pacific and South Atlantic |
| Lifespan: | Up to 19 years |
| Size: | Up to 6m 20 ft long |
| Weight: | Up to 4,000 kg (8,820 pounds) |
| Colour: | Black or reddish-brown |
| Diet: | Squid, fish, sharks, rays |
| Predators: | Killer whales and great whites |
| Top Speed: | 8 km/h (5.0 mph) on land 16 kph (10 mph) in the water |
| No. of Species: | 2 |
| Conservation Status: | Both species are of Least Concern (IUCN) |
Elephant seals are an overlooked marine mammal in a number of ways, but they are well-recognised for their size.
What might go unnoticed is just how deep they can dive and how far they travel throughout their lifetimes.
They also have excellent vision for low light conditions and are one of the greatest examples of a conservation success story you can find.
Interesting Elephant Seal Facts
1. They’re not elephants
Only half of the elephant seal’s name is accurate. While males sport some impressive trunks, these do not originate from the same evolutionary path as elephants and evolved entirely independently.
They are, however, seals. And true seals, at that. And they’re elephantine in their order, as the largest seals, and the largest carnivorans. These seals can grow to immense proportions, with particularly large males reaching up to four tons.
There are two species: the Southern and Northern elephant seals. The Northern being the smaller of the two and is common all over the Pacific coast of North America.
The Southern elephant seals are only found in the Southern Hemisphere and occupy some pretty chilly locations as far down as Antarctic waters. 1
2. They’re hugely sexually dimorphic
Most mammals exhibit some level of difference in the sexes. Usually, it’s a size thing, with males typically being larger than females, but in 22% of cases, it’s the other way around.
Elephant seals don’t defy this convention but they do excel at it. A male elephant seal can weigh up to ten times the amount a female does, making them one of the most extreme cases in the mammalian class.
3. They’re marine animals
It’s easy to consider an animal like this as semi-aquatic. Most of the time you see them, they’re on land, but this belies their true nature. Elephant seals spend a surprisingly small proportion of their time out of the water, with some sources claiming 80% of their lives are spent in the ocean.
When in the ocean, they’re almost always beneath the surface, only coming up to take a breath and a brief rest before heading back down. And in this, too, they’re experts. 2
4. They’re expert divers
Elephant seals have been recorded diving down to as far as 1,550 meters beneath the surface. This is an astonishing feat for a mammal and the only two species known to surpass it are the sperm whale and the Cuvier’s beaked whale.
For such an extreme task, they have some extreme adaptations. Their blood volume is enormous, allowing them to carry vast amounts of blood with vast amounts of oxygen dissolved in it. Their muscles have extra myoglobin to carry even more oxygen than normal, and they have more red blood cells, too.
When diving, they can slow their heartbeats to 3 beats per minute and divert blood to the brain and other vital organs, as well as slow down their metabolism to reduce the build-up of waste.
With all of these attributes, they can stay underwater for an alarming two hours at a time, using barely any energy to dive, and just letting gravity do its work.
5. They have excellent night vision
Spending so much time at depth is similar to spending a lot of time at night: there isn’t a lot of light available. So, elephant seals have huge, round eyes with densely clustered rods in their retinas to pick up as much of the scarce light as possible.
They also have a tapetum lucidum, which you will have seen reflecting your torchlight back at you in other animals like cats and sheep. This reflective membrane in the eye helps amplify any light that it picks up and is common in nocturnal mammals, and elephant seals have the most prominent example of this of all pinnipeds. 3
6. They’re long-distance swimmers
These marine giants aren’t so fast but they still get a lot done. Not only are they record-divers, they also traverse great distances, swimming up to 32,000km a year. Much of this is done at a leisurely 16 km/h, but consistency is key here, and maintaining this speed throughout the majority of their time in the water really racks up the miles. 4
7. They were hunted almost to extinction
During the 1800s, Northern elephant seals were hunted almost all the way out of existence. It was only the efforts of Mexican conservationists that brought them back from the brink, using a breeding population of fewer than 100 individuals.
This destruction came from the demand for blubber and led to the species being declared extinct in many locations, but from that small population discovered in Mexico, they now number more than 150,000 and both species are listed as of Least Concern by the IUCN Red List.
Elephant Seal Fact-File Summary
Scientific Classification
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Phocidae |
| Genus: | Mirounga |
Fact Sources & References
- Glenn R. Van Blaricom (2013), “Northern Elephant Seal”, Science Direct.
- “Mirounga leonina southern elephant seal”, Animal Divesity Web.
- Hrvoje Smodlaka (2016), “Eye Histology and Ganglion Cell Topography of Northern Elephant Seals (Mirounga angustirostris)”, National Institute of Medicine.
- “An Elephant Seal’s Deep Dive”, Friends of the Elephant Seal.