6 Reasons to Supersize

The following post is authored by Caroline Schanche as part of the Sizing Ocean Giants project. This post originally occurred on the Story of Size.

For those who have seen elephant seals up close and personal, there is no questioning the fact that elephant seals are not afraid to put on the pounds. This guy surely doesn’t seem to mind his blubbery appearance:

Flickr Stephen Gough

(Flickr Stephen Gough)

In other words, there is a whole lot of fat on them. However, the word fat does not do them justice, so I took the liberty of looking up some synonyms (from thesaurus.com). Therefore we can also call elephant seals bulging, bull, butterball, chunky, heavy, hefty, heavyset, husky, meaty, plump, distended, solid, stout, swollen, beefy, brawny, burly, gargantuan, and my personal favorite: jelly-belly.

Jelly-belly seems appropriate. From Flickr mikebaird

Jelly-belly seems appropriate. (Flickr mikebaird)

So sit back, relax and enjoy, as elephant seals show us the benefits of being a butterball.

1. Stay toasty

Elephant seals are the largest of all seals. The southern elephant seal Mirounga leonina can grow to be 8,800lbs and 20 ft long. In adult males, up to 50% of this mass comes from blubber, which is a thick layer made up of fat which has a dense system of blood vessels and lymphatic vessels. Since it is a thicker layer and contains more blood than normal fat layers, it provides a ton of insulation and is one of the main methods for thermoregulation. In other words, these elephant seals will stay warm and toasty all year long. More blubber means more thermoregulation, therefore bring on the brisket because its time to eat. Interestingly, some humans actually do need to do something similar when travelling to extremely cold places such as Antarctica to maintain warmth and to not become severely underweight, although hopefully they don’t get to super-sized conditions.

 2. Get them Ladies

Larger elephant seals get more girls. It really is that simple. When the seals arrive at a beach for mating season the males all battle it out to find out who’s the boss: the alpha male, or the beach master. Elephant seals are known for this fighting and it usually goes a little something like this:

The beach master is the one who gets to copulate (not my favorite word) with the most females, which is exciting for him I guess. Does this apply to us? Is it always the biggest (read: chunkiest) guys who are more likely to get lucky? ehhhh, I’d have to go with no. If we’re talking muscle it might be different, but in this case the seals are a whole lot of blubber. Not my thing, but maybe its exactly what a female elephant seal wants.

Sex. Appeal. (FlickrElizabeth Haslam)

Sex. Appeal. (FlickrElizabeth Haslam)

3. Dive Deep into the Blue

Elephant seals dive very deep down to get to their favourite food sources of skates, rays, squid, octopus and eels. They can spend almost 90% of their entire day underwater and can swim down as deep as 300m! How can they do this? Well, all those blood vessels in the blubber as well as an unusually high blood volume along with higher levels of haemoglobin and myoglobin allow them to have a very high oxygen storage capacity. Kind of a cool thing to be able to do.

Excuse me while I take a quick 80min dive.

Excuse me while I take a quick 80min dive.

4. Be Your Own Buffet

All that blubber is good for a lot of things, but one of the best is that the seals can live off of it for months during mating season. Although at the end of it both the males and the females can have lost as much as a third of their body weight, they are still living the life if they don’t even have to worry about food. They have a specialized metabolism with water as a byproduct, and can live off the food stores in their blubber all mating season long, giving them time to focus on… other things.

I know I can get lazy when it comes to making food sometimes and it could be nice to have a fat store to keep you from getting starved, however with us it doesn’t really work that way. Getting fat doesn’t keep you from eating, although I wish it did.

When you’re too lazy to make food so you just:

 5. Do the BlubbrBounce

Elephant seals clearly need their blubber so that they can present this masterpiece to the world:

6. Get away with being an scumbag

All week I have been tweeting about the scumbag elephant seal (shameless plug: @carolinetime9), because their large size and certain things they do could be considered particularly “scumbaggy” (see below).

3t0gv

However, no matter how much of an scumbag you are, nobody, and I mean nobody, is going to try to mess with you if you look like this:

Therefore, their size and intimidating (read: ugly) appearance means they can do whatever they want (at least the alpha males can) because very few can take them on.

To conclude, I think Elephant seals clearly make their mass work for them, and are arguably one of the species that can pull off such a great amount of blubber. They have good reasons for their bodacious, unlike us humans. Some might disagree though:

References

Haley, M.P., C.J. Deutsch, and B. Le Boeuf. “Size, Dominance and Copulatory Success in Male Northern Elephant Seals, Mirounga Angustirostris.” Animal Behaviour 48 (1994): 6. Print.

LeBoeuf, Burney J. Elephant Seals: Population, Ecology, Behavior, and Physiology. Berkeley, Calif. [u.a.: Univ. of California Press, 1994. Print.

http://www.parks.ca.gov/?page_id=1115

https://sites.google.com/site/elephantsealnotes/physical-characteristics

http://deepseanews.com/2013/03/battle-of-the-living-instrument-platforms-elephant-seals-vs-narwhals/

Dr. M (1618 Posts)

Craig McClain is the Assistant Director of Science for the National Evolutionary Synthesis Center, created to facilitate research to address fundamental questions in evolutionary science. He has conducted deep-sea research for 11 years and published over 40 papers in the area. He has participated in dozens of expeditions taking him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses mainly on marine systems and particularly the biology of body size, biodiversity, and energy flow. He focuses often on deep-sea systems as a natural test of the consequences of energy limitation on biological systems. He is the author and chief editor of Deep-Sea News, a popular deep-sea themed blog, rated the number one ocean blog on the web and winner of numerous awards. Craig’s popular writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web.





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