Elephant seal

About Elephant seals

You may have seen (and heard) elephant seals on a beach: roaring, clumsy and (let’s face it) terrifying as they jostle for mates. These enormous, blubbery marine mammals awkwardly belly-flop around on land, but are elegantly adapted for life in the twilight zone—where they spend 90% of their at-sea time.

Two distinct species, the Northern and Southern elephant seal, are among the largest carnivores in the ocean. It takes a whole lot of food to power a 3,000-kg (7,000 lb) body, and they’ll work for it, diving up to 1,700 meters (5,600 feet) in pursuit of fish prey. Elephant seals are known to hold their breath for nearly two hours, allowing them to stay at twilight zone depths for an extended period before surfacing for a few minutes breather. A thick layer of blubber keeps them warm, while their circulatory system is uniquely adapted to carry extra oxygen, prioritize core organs, slow their metabolism, and maintain constant body temperature in the frigid depths.

Elephant seals’ large eyes are specialized to detect bioluminescent glimmers in low light, but they rely just as much on other senses to hunt and escape sharks and orcas in the twilight zone. Their inner ears have adapted to amplify sound and adjust to pressure changes, while their whiskers (called vibrissae) help the seal locate prey and navigate—much like a cat’s whiskers.

Elephant seals are known to travel 5,000 kilometers (3,000 miles) between their rookery (haul-out) and foraging grounds, and females will typically spend two months more time foraging than males. When the time comes (in the boreal spring for Northern species), elephant seals haul out onto sandy beaches. They fast for two months, while females give birth and males fight for the chance to mate. Apparently, the snout that gives the elephant seal its name is a serious turn-on for the ladies.