14 Huge Facts About Elephant Seals


Extreme divers and polygamous lovers, these “elephants of the sea” are some of the oddest marine mammals alive—which is saying something.


Hit any beach from Alaska to Mexico and you just might spot a northern elephant seal (Mirounga angustirostris) colony. Of the two species, this one’s smaller in overall size—though males come with longer trunks. To spot southern elephant seals (Mirounga leonina), you'll have to travel below the equator.


Slaughtered en masse for their oil-producing blubber, the northern elephant seal was at one time close to extinction. By 1892, many assumed that this poor species had quietly disappeared forever.

However, a small breeding colony managed to endure. It was estimated that, in 1910, some 20 to 100 northern elephant seals were still alive. All of these survivors dwelled on or around Guadalupe Island off Mexico’s Baja California coast. Things finally started to turn around for the species in 1922, when the island became a biological reserve, and the seals received government protection. Since then, the global population has ballooned up to 160,000—all of whom are descended from those Guadalupe Island holdouts.


Seals, sea lions, and walruses are collectively known as pinnipeds. Unlike most other ocean-going mammals (like whales and dugongs), these beasts aren’t fully aquatic: They clamber out of the water to rest, molt, mate, and rear pups. There are 33 known pinniped species, and the absolute biggest is the southern elephant seal. From end to end, large individuals can grow to lengths of 20 feet and weigh up to 8800 pounds.


Next to a 4.5-ton bull, female southern elephant seals look puny. In general, males are seven or eight times heavier than females and can be twice as long. For northern elephant seals, the situation is similar, but less extreme. In this species, males max out at around 13 feet long and 4500 pounds, while the heftiest females are some 3000 pounds lighter and 3 feet shorter in length.


In 2012, marine biologists tracked a northern female’s progress as she descended to the amazing depth of 5788 feet under the surface. Elephant seals are great at holding their breath and can remain submerged for up to two hours straight.


What exactly do elephant seals do during those epic dives? Grab some calamari. By dissecting stomachs from dead specimens, scientists have learned that the mammals have a squid-based diet. Elephant seals also eat fish and crustaceans—albeit less often.


A male’s most conspicuous feature is, of course, something that females lack—namely, his bulbous nose, which comes with a sack-like appendage known as a proboscis. Expanding the proboscis enables an elephant seal to amplify snorts, grunts, and loud, drum-like bellows that can be heard several miles away.


The proboscis’s main function is to emit noises that—ideally—ward off rival males, stopping fights before they start. Over time, a masculine hierarchy is established—but it looks like a bull can’t climb very far up the ladder until he’s backed up a few threats.

For a four year period beginning in 2009, a team from the University of California Santa Cruz conducted an experiment with some nearby elephant seals. The scientists set up shop along the beaches of Año Nuevo State Park and recorded the warning calls made by individual males who frequented the area, then broadcasted them over a speaker later.

“What we were interested in is what type of information is contained in the vocalizations produced by males and how this information is used during the breeding season,” graduate student Caroline Casey says in the above video. “We found that when we played back the call of an animal’s most familiar dominant rival, he actually moved away from the speaker.” Conversely, broadcasting grunts from a subordinate triggered the opposite reaction. In that situation, Casey says, the same male “attacked, or called at the speaker.”

But how would a bull from some completely different breeding colony react? To find out, Casey and her colleagues visited a cluster of elephant seals residing 300 miles south. By and large, the team’s recordings had no effect there. “Only three out of the 20 males that we did playbacks to moved at all,” Casey says.

The researchers concluded that a “back off!” cry means nothing if the listener doesn’t recognize the voice in question. According to Casey, “They only really know how to assess these calls if they’ve had previous interactions with [the callers].”


On dry land, elephant seals often go without drinking for extended periods. To avoid dehydration, their kidneys can produce concentrated urine that contains more waste and less actual water in every drop. After a few drinks, they switch back to excreting standard pee.


A colony’s most dominant bull—also known as a “harem master”—rounds up many of its females for himself. He then more or less maintains exclusive reproductive access to just about every single one of them—that is, until a competitor dethrones him.

A massive elephant seal paternity test revealed just how prolific a harem master can be. Conducted in the Falkland Islands, this study examined one large colony over a two-year period. A whopping 90 percent of documented pups were fathered by dominant males, and harem masters produced as many as 125 offspring. On the other hand, 72 percent of subordinate males were never observed mating—not even once. Tough break.


When a mother elephant seal gives birth, the milk she secretes is around 12 percent fat. Two weeks later, that number increases to over 50 percent, giving the liquid a pudding-like consistency. By comparison, cow milk is only 3.5 percent fat.


Once the lactation process starts, these pups grow up fast: In just 30 days, an average pup will go from weighing 75 to 300 pounds.


In The Lord of the Rings: The Fellowship of the Ring, scrawny, cave-dwelling Moria orcs emit an eerie battle screech. When creating their cries, sound effects designer David Farmer found an oceanic source of inspiration.

“[The] major signature sound for them was … elephant seal pups,” he said in 2010. Farmer describes the unique noise as "a nice projecting call," lending itself nicely to reverberation. "The scene in the mines of Moria at the 'Drums in the deep' are all elephant seals distanced.”

These aren't the only pinniped noises in the trilogy. According to Farmer, the muscle-clad Uruk orcs were vocally based “on sea lions, especially for the pain reactions, with tigers and leopards for more aggressive attacks.”


All was peaceful in Gisborne, New Zealand—until Homer came along. Named after everyone’s favorite Simpsons character, Homer was, according to the narrator of the above video, “a 14 foot-long, 4500-pound [southern] elephant seal who likes to turn parked cars into punching bags.”

His reign of terror began in May 2000. Seemingly without provocation, Homer rose from the depths and attacked at least three cars, multiple boat trailers, a pothutukawa tree, and a trash bin. In the process, he became something of a minor celebrity, appearing on news broadcasts all over the world. Later, Homer strolled over to an unsuspecting restaurant, struck the outside transformer, and singlehandedly knocked out the establishment’s power.

Weird as it may sound, these all could have been crimes of passion. “Homer has got a bit of a problem,” Andy Bassett, a member of New Zealand’s Department of Conservation, told the BBC. “He’s actually attracted to cars, and his two tonnes rubbing on a car makes a bit of a dent. We are hoping that he will take off and go back to the sub-Antarctic and try to look for lady friends down there.”

Soon enough, Homer did indeed bid Gisborne farewell, but it’s fair to say that the townspeople will never forget him.

All images courtesy of iStock

Animal Welfare Groups Are Building a Database of Every Cat in Washington, D.C.

There are a lot of cats in Washington, D.C. They live in parks, backyards, side streets, and people's homes. Exactly how many there are is the question a new conservation project wants to answer. DC Cat Count, a collaboration between Humane Rescue Alliance, the Humane Society, PetSmart Charities, and the Smithsonian Conservation Biology Institute, aims to tally every cat in the city—even house pets, The New York Times reports.

Cities tend to support thriving feral cat populations, and that's a problem for animal conservationists. If a feline is born and grows up without human contact, it will never be a suitable house cat. The only options animal control officials have are to euthanize strays or trap and sterilize them, and release them back where they were found. If neither action is taken, it's the smaller animals that belong in the wild who suffer. Cats are invasive predators, and each year they kill billions of birds in the U.S. alone.

Before animal welfare experts and wildlife scientists can tackle this problem, they need to understand how big it is. Over the next three years, DC Cat Count will use various methods to track D.C.'s cats and build a feline database for the city. Sixty outdoor camera traps will capture images of passing cats, relying on infrared technology to sense them most of the time.

Citizens are being asked to help as well. An app is currently being developed that will allow users to snap photos of any cats they see, including their own pets. The team also plans to study the different ways these cats interact with their environments, like how much time pets spend indoors versus outdoors, for example. The initiative has a $1.5 million budget to spend on collecting data.

By the end of the project, the team hopes to have the tools both conservationists and animal welfare groups need to better control the local cat population.

Lisa LaFontaine, president and CEO of the Humane Rescue Alliance, said in a statement, “The reality is that those in the fields of welfare, ecology, conservation, and sheltering have a common long-term goal of fewer free-roaming cats on the landscape. This joint effort will provide scientific management programs to help achieve that goal, locally and nationally."

[h/t The New York Times]

How Does Catnip Work?

If you have a cat, you probably keep a supply of catnip at home. Many cats are irresistibly drawn to the herb, and respond excitedly to its scent, rubbing against it, rolling around on the floor, and otherwise going nuts. There are few things that can get felines quite as riled up as a whiff of catnip—not even the most delicious treats. But why does catnip, as opposed to any other plant, have such a profound effect on our feline friends?

Catnip, or Nepeta cataria, is a member of the mint family. It contains a compound called nepetalactone, which is what causes the characteristic catnip reaction. Contrary to what you might expect, the reaction isn’t pheromone related—even though pheromones are the smelly chemicals we usually associate with a change in behavior. While pheromones bind to a set of specialized receptors in what’s known as a vomeronasal organ, located in the roof of a cat's mouth (which is why they sometimes open their mouths to detect pheromones), nepetalactone binds to olfactory receptors at the olfactory epithelium, or the tissue that lines the mucus membranes inside a cat’s nose and is linked to smell.

Scientists know the basics of the chemical structure of nepetalactone, but how it causes excitement in cats is less clear. “We don’t know the full mechanisms of how the binding of these compounds to the receptors in the nose ultimately changes their behavior,” as Bruce Kornreich, associate director of the Cornell Feline Health Center, tells Mental Floss. Sadly, sticking a bunch of cats in an MRI machine with catnip and analyzing their brain activity isn’t really feasible, either from a practical or a financial standpoint, so it’s hard to determine which parts of a cat’s brain are reacting to the chemical as they frolic and play.

Though it may look like they’re getting high, catnip doesn’t appear to be harmful or addictive to cats. The euphoric period only lasts for a short time before cats become temporarily immune to its charms, meaning that it’s hard for them to overdo it.

“Cats do seem to limit themselves," Michael Topper, president of the American Veterinary Medical Association, tells Mental Floss. "Their stimulation lasts for about 10 minutes, then it sort of goes away.” While you may not want to turn your house into a greenhouse for catnip and let your feline friend run loose, it’s a useful way to keep indoor cats—whose environment isn’t always the most thrilling—stimulated and happy. (If you need proof of just how much cats love this herb, we suggest checking out Cats on Catnip, a new book of photography from professional cat photographer Andrew Martilla featuring dozens of images of cats playing around with catnip.)

That said, not all cats respond to catnip. According to Topper, an estimated 70 percent of cats react to catnip, and it appears to have a genetic basis. Topper compares it to the genetic variation that causes some individuals to smell asparagus pee while others don’t. Even if a cat will eventually love the smell of catnip, it doesn’t come out of the womb yearning for a sniff. Young kittens don’t show any behavioral response to it, and may not develop one until several months after birth [PDF].

But some researchers contend that more cats may respond to catnip than we actually realize. In one 2017 study, a group of researchers in Mexico examined how cats might subtly respond to catnip in ways that aren’t always as obvious as rolling around on the floor with their tongue hanging out. It found that 80 percent of cats responded to catnip in a passive way, showing decreased motor activity and sitting in the “sphinx” position, an indicator of a relaxed state.

There are also other plants that have similar effects on cats, some of which may appeal to a wider variety of felines than regular old catnip. In a 2017 study in the journal BMC Veterinary Research, researchers tested feline responses to not just catnip, but several other plants containing compounds similar in structure to nepetalactone, like valerian root, Tatarian honeysuckle, and silver vine. They found that 94 percent of cats responded to at least one of the plants, if not more than one. The majority of the cats that didn’t respond to catnip itself did respond to silver vine, suggesting that plant might be a potential alternative for cats that seem immune to catnip’s charms.

Despite the name, domestic cats aren’t the only species that love catnip. Many other feline species enjoy it, too, including lions and jaguars, though tigers are largely indifferent to it. The scent of the plant also attracts butterflies. (However, no matter what you’ve heard, humans can’t get high off it. When made into a tea, though, it reportedly has mild sedative effects.)

The reason Nepeta cataria releases nepetalactone doesn’t necessarily have to do with giving your cat a buzz. The fact that it gives cats that little charge of euphoria may be purely coincidental. The chemical is an insect repellant that the plant emits as a defense mechanism against pests like aphids. According to the American Chemical Society, nepetalactone attracts wasps and other insect predators that eat aphids, calling in protective reinforcements when the plant is in aphid-related distress. That it brings all the cats to the yard is just a side effect.

Because of this, catnip may have even more uses in the future beyond sending cats into a delighted frenzy. Rutgers University has spent more than a decade breeding a more potent version of catnip, called CR9, which produces more nepetalactone. It’s not just a matter of selling better cat toys; since catnip releases the compound to ward off insects, it’s also a great mosquito repellant, one that scientists hope can one day be adapted for human use. In that case, you might be as excited about catnip as your cat is.

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