World's Largest Seal Can Grow To The Length Of A Shipping Container

At 4,000 kilograms, your puny scale banana is but a speck.


Rachael Funnell


Rachael Funnell

Digital Content Producer

Rachael is a writer and digital content producer at IFLScience with a Zoology degree from the University of Southampton, UK, and a nose for novelty animal stories.

Digital Content Producer

worlds largest seal

A four-ton southern elephant seal blocking your driveway is at least an original reason to be late for work. Image credit: Air55 - Own work, CC BY-SA 4.0, via Wikimedia 

Line up the skulls of grizzlies and black bears and they’ll look like spuds compared to that of the southern elephant seal (something Steve Backshall handily did in a video for BBC Earth back in 2007, in case you want to take a look). They are the biggest seals on the planet, weighing up to four tons in particularly beefy males, and can be as long as a shipping container.

southern elephant seal
Behold, The Seal Scale. Image credit: IFLScience

Female southern elephant seals (Mirounga leonina) typically reach a maximum length of 3 meters (10 feet), but the males can be almost double that at just shy of 6 meters (20 feet), and three times as heavy. Their enormous size is one reason for their name, but these animals also boast peculiar noses that are a hat tip to the terrestrial elephant.

southern elephant seal
For scale, those penguins just short of a meter tall. That Jabba The Hut for a southern elephant seal? Who knows. Image credit: CherylRamalho /

The proboscis of male elephant seals is an exaggerated secondary sexual trait, meaning it’s an adaptation that improves these animals’ chances of reproductive success. It’s a sexually dimorphic feature that’s only present in males and starts to become apparent when the seal is around three years old.

The size of a male elephant seal’s nose can be used as an indicator of age, and it gets bigger with the size of the animal. The males have evolved to need to wear their dominance on their faces because their social groups operate in harems, whereby a male will defend its mates from rival males.

Being big with a schnozz that flaps in the breeze goes some way to keeping excitable males at bay, but eventually, there comes a time in every male southern elephant seal’s life when he has to go to battle. Fights between rival males are epic affairs, each weighing about the same as a car and wielding four dagger-like teeth to boot.

Before the brawling, males can utilize their bagpipe-like noses to resonate sounds as they make aggressive vocalizations to try and put off competitors. They may also use them to hit just the right melody when trying to woo a female. However, a study that used observations and photographs to study the role of elephant seal proboscis in the field concluded there may be a lot more going on with these noses than meets the human eye.

southern elephant seals
You do not want to get in the middle of two male southern elephant seals fighting. Image credit: Laëtitia Kernaléguen (Deakin University), CC BY 2.0, via Wikimedia

“The function of elephant seal proboscis remains elusive and largely speculative,” the authors concluded. “The proboscis can have a role in the visual displays and in the emission of vocalizations that males use to establish dominance; it can be related to the hormonal status of the male, and testosterone in particular; and it is a potential cue for female choice. However, for now, there is strong support only for a role of the proboscis in the vocalizations.”

Looking upon the sentient log that is a southern elephant seal, there’s one thing we can know for certain: These babies are absolute units.

Now, would you like to meet the world’s largest terrestrial predator?


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