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Male Sea Lions are Lazy Mama’s Boys

Image Credit: David Adam Kess, Wikimedia Commons // CC BY SA-3.0

Galapagos sea lions aren’t the most independent children in the animal kingdom. They nurse on their mothers’ milk until they’re two or three years old, and sometimes even longer. Scientists have seen sea lions as old as seven, with pups of their own, still relying on mom for food. 

Clearly, motherhood is an investment for sea lions, but male pups present a special challenge. From birth, they’re larger than females and need extra calories to meet their energy needs. Scientists assumed that mothers simply fed their sons more, but a group of German researchers wasn’t so sure about that. Recent research showed that sea lion pups begin hunting when they’re about a year old and supplement their milk diet with fish, and ecologist Fritz Trillmich thought that male sea lions might take some strain off their moms and get their extra calories on their own by hunting more than female pups. 

After studying groups of sea lions in the Galapagos, though, he found that male pups really are just mama’s boys

Trillmich and his research team at Bielefeld University have been monitoring a colony of sea lions on the tiny island of Caamaño since 2003. For this new study, they tracked more than 100 pups in three age groups (1 year olds, 1.5 year olds, and 2 year olds) that were both nursing and foraging on their own. Glue-on tags that recorded location and depth told them how far the sea lions roamed from the colony, and how often and how deep they dove while looking for food. The scientists also figured out what the pups were eating by analyzing skin samples taken from some of the tracked animals and their mothers and comparing chemical signatures that come from their diets. 

That’s My Daughter in the Water

The results showed that female pups in all three age groups ventured farther out and were more active divers, while the males stuck close to home and rarely went diving. Female pups wandered as far as 18 miles away from their moms, while the males never got much farther than 650 feet. Out on their own, the female pups spent more time in the water, and dove more often than the males. They also had more fish and other solid food in their diets, while the males fed mostly on milk. 

The researchers didn’t see any difference in diving skill between males and females. The males that did go out into the ocean showed they could dive just as deep as the females and spend about as much time underwater. The difference between the sexes, the team says, isn’t one of diving ability, but effort. For some reason, female pups are more self-reliant when it comes to food, while males—contrary to what the researchers expected—mostly rely on mom to feed them even though they could hunt for themselves. 

Beasts of Burden

Providing for a stay-at-home son can cost a sea lion mother dearly, the researchers say. Keeping a male pup supplied with milk requires more energy and could prevent the mother from having additional pups that she couldn’t support. The heavy investment in male pups might pay off if they mate with lots of females and spread their genes around, but the researchers think this is unlikely since males don’t produce that many more offspring than females. 

While it seems that young male sea lions have it easy, their lazy ways can catch up with them in the long run. The researchers think that female pups’ early independence may help them mature faster, giving them more years to breed and have pups on their own, while late-blooming males have to wait longer until they can mate. The extra hunting experience may also make female sea lions more resilient when the going gets tough. During lean times when their mothers have to spend more time hunting or can’t supply as much milk, female pups can fend for themselves, while males are left high and dry and are less likely to survive. 

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Big Questions
Why Do Cats 'Blep'?
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As pet owners are well aware, cats are inscrutable creatures. They hiss at bare walls. They invite petting and then answer with scratching ingratitude. Their eyes are wandering globes of murky motivations.

Sometimes, you may catch your cat staring off into the abyss with his or her tongue lolling out of their mouth. This cartoonish expression, which is atypical of a cat’s normally regal air, has been identified as a “blep” by internet cat photo connoisseurs. An example:

Cunning as they are, cats probably don’t have the self-awareness to realize how charming this is. So why do cats really blep?

In a piece for Inverse, cat consultant Amy Shojai expressed the belief that a blep could be associated with the Flehmen response, which describes the act of a cat “smelling” their environment with their tongue. As a cat pants with his or her mouth open, pheromones are collected and passed along to the vomeronasal organ on the roof of their mouth. This typically happens when cats want to learn more about other cats or intriguing scents, like your dirty socks.

While the Flehmen response might precede a blep, it is not precisely a blep. That involves the cat’s mouth being closed while the tongue hangs out listlessly.

Ingrid Johnson, a certified cat behavior consultant through the International Association of Animal Behavior Consultants and the owner of Fundamentally Feline, tells Mental Floss that cat bleps may have several other plausible explanations. “It’s likely they don’t feel it or even realize they’re doing it,” she says. “One reason for that might be that they’re on medication that causes relaxation. Something for anxiety or stress or a muscle relaxer would do it.”

A photo of a cat sticking its tongue out
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If the cat isn’t sedated and unfurling their tongue because they’re high, then it’s possible that an anatomic cause is behind a blep: Johnson says she’s seen several cats display their tongues after having teeth extracted for health reasons. “Canine teeth help keep the tongue in place, so this would be a more common behavior for cats missing teeth, particularly on the bottom.”

A blep might even be breed-specific. Persians, which have been bred to have flat faces, might dangle their tongues because they lack the real estate to store it. “I see it a lot with Persians because there’s just no room to tuck it back in,” Johnson says. A cat may also simply have a Gene Simmons-sized tongue that gets caught on their incisors during a grooming session, leading to repeated bleps.

Whatever the origin, bleps are generally no cause for concern unless they’re doing it on a regular basis. That could be sign of an oral problem with their gums or teeth, prompting an evaluation by a veterinarian. Otherwise, a blep can either be admired—or retracted with a gentle prod of the tongue (provided your cat puts up with that kind of nonsense). “They might put up with touching their tongue, or they may bite or swipe at you,” Johnson says. “It depends on the temperament of the cat.” Considering the possible wrath involved, it may be best to let them blep in peace.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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Animals
Why Crows Hold Noisy Funerals for Their Fallen Friends
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The next time you hear a murder of crows cackling for no apparent reason, show a little respect: You may have stumbled onto a crow funeral. Crows are among the few animals that exhibit a social response to a dead member of their species. Though their caws may sound like heartbroken cries, such funerals aren't so much about mourning their fallen friends as they are about learning from their mistakes.

In the video below from the PBS series Deep Look, Kaeli Swift, a researcher at the University of Washington's Avian Conservation Lab, investigates this unusual phenomenon firsthand. She familiarized herself with a group of crows in a Seattle park by feeding them peanuts in the same spot for a few days. After the crows got used to her visits, she returned to the site holding a dead, taxidermied crow and wearing a mask and wig to hide her identity. The crows immediately started their ritual by gathering in the trees and crying in her direction. According to Swift, this behavior is a way for crows to observe whatever might have killed the dead bird and learn to avoid the same fate. Flocking into a large, noisy group provides them protection from the threat if it's still around.

She tested her theory by returning to the same spot the next week without her mask or the stuffed crow. She offered the crows peanuts just as she had done before, only this time the birds were skittish and hesitant to take them from her. The idea that crows remember and learn from their funerals was further supported when she returned wearing the mask and wig. Though she didn't have the dead bird with her this time, the crows were still able to recognize her and squawked at her presence. Even birds that weren't at the funeral learned from the other birds' reactions and joined in the ruckus.

Swift was lucky this group of crows wasn't particularly vengeful. Crows have been known to nurse and spread grudges, sometimes dive-bombing people that have harmed one of their own.

[h/t Deep Look]

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