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Emory University
Emory University

Scientists Say Prairie Voles Can Comfort Each Other

Emory University
Emory University

We’re not the only animals that get by with a little help from our friends. A report published last week in the journal Science shows that prairie voles can sense distress in other voles and will rush to comfort them, just like humans.

Scientists are hesitant to ascribe emotions or motivations to non-human animals. As a result, the general consensus has become “animals don’t have emotions,” a statement that tends to rankle both animal lovers and certain ethologists (animal behaviorists).

Primatologist Frans de Waal is one of those people. He’s spent decades studying nonhuman primates and other animals, and believes the human capacities for morality and empathy are far from unique.

The difficulty lies in proving it. Designing an experiment that will unequivocally demonstrate a certain emotion is extremely difficult for two reasons: first, we can’t just ask other animals what’s going on in their heads, and second, such an experiment would have to control for a lot of other variables. The results would have to show that the animals weren’t motivated by anything else, which is pretty hard to pull off. There have been some successes; one study showed that dogs enjoy being generous with their friends, while another showed that the reverse is true for capuchin monkeys.

The recent prairie vole study makes another compelling case for animal emotion. The experiment included not only watching pairs of roly-poly prairie voles (Microtus ochrogaster) to see how they behaved, but also analyzing their brain chemistry and activity. Prairie voles are an especially social species, living in colonies that would definitely benefit from empathetic behaviors.

The researchers studied the voles in pairs and found that when one vole was distressed, its partner would respond by rushing to groom it. Humans and other primates tend to console each other with hugs and kisses, but for voles, grooming is the way to go. Voles who knew each other were quicker and more likely to approach and groom, a behavior that mirrors the gift-giving dogs’ preference for their friends over strangers.

The comforting behavior had both chemical and anatomical components. The experimenters found that oxytocincommonly called the “love hormone” for its association with romantic and maternal love in humanswas a major driver of the voles’ empathetic impulses. When the scientists shut off oxytocin signaling in the voles’ brains, the rodents became less concerned about their partners.

The researchers also found that seeing other voles upset or in trouble activated a brain region called the anterior cingulate cortexthe same part of the brain that gets to work when a human sees another human in distress. This type of brain activity has been shown in non-human primates before, but never in other animals.

Empathy expert de Waal, an author on the paper, believes the study to be an important step in the right direction. “Scientists have been reluctant to attribute empathy to animals, often assuming selfish motives,” he says in a press release. “These explanations have never worked well for consolation behavior, however, which is why this study is so important.”

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Slow Motion Is the Only Way to Appreciate a Chameleon’s Lightning-Fast Tongue
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From the unusual way they walk, to their ability to change color, the evolutionary adaptations of chameleons are pretty bizarre, and some of them remain mysterious even to scientists. Their super-powered tongues, for instance, can dart out so quickly that the movement can barely be seen with the naked eye. But modern high-speed cameras have enabled researchers at the University of South Dakota to observe this appendage at work like never before. The video below, shared over at The Kid Should See This, includes some of that groundbreaking footage, and it's pretty amazing to watch.

Shooting at 3000 frames per second, the camera was able to capture every split-second aspect of the chameleon's tongue strike. Slowed down, the video allows you to see how every component of the process works in harmony: First, muscles in the lizard’s tongue contract like the string of a bow. Then, when that tension is released, the bony base of the tongue shoots forward, pushing the sticky, elastic part toward the chameleon’s prey.

According to Christopher Anderson, one of the scientists who conducted the high-speed camera research, larger chameleons can catapult their tongues forward at distances of one to two times their body length. For smaller chameleons, this distance can reach up to two and a half times their body length. “Small chameleons need to be able to eat more food for their body size than large chameleons,” he tells bioGraphic in the video, “and so by being able to project their tongues proportionately further than these large species, they basically are opening up additional feeding opportunities to themselves that they wouldn’t have if they had a shorter tongue.”

To see one of nature’s greatest hunting tools in action, check out the full video below.

[h/t The Kid Should See This]

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There May Be an Ancient Reason Why Your Dog Eats Poop
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Dogs aren't known for their picky taste in food, but some pups go beyond the normal trash hunting and start rooting around in poop, whether it be their own or a friend's. Just why dogs exhibit this behavior is a scientific mystery. Only some dogs do it, and researchers aren't quite sure where the impulse comes from. But if your dog is a poop eater, it's nearly impossible to steer them away from their favorite feces.

A new study in the journal Veterinary Medicine and Science, spotted by The Washington Post, presents a new theory for what scientists call "canine conspecific coprophagy," or dogs eating dog poop.

In online surveys about domestic dogs' poop-eating habits completed by thousands of pet owners, the researchers found no link between eating poop and a dog's sex, house training, compulsive behavior, or the style of mothering they received as puppies. However, they did find one common link between the poop eaters. Most tended to eat only poop that was less than two days old. According to their data, 85 percent of poop-eaters only go for the fresh stuff.

That timeline is important because it tracks with the lifespan of parasites. And this led the researchers to the following hypothesis: that eating poop is a holdover behavior from domestic dogs' ancestors, who may have had a decent reason to tuck into their friends' poop.

Since their poop has a high chance of containing intestinal parasites, wolves poop far from their dens. But if a sick wolf doesn't quite make it out of the den in time, they might do their business too close to home. A healthier wolf might eat this poop, but the parasite eggs wouldn't have hatched within the first day or two of the feces being dropped. Thus, the healthy wolf would carry the risk of infection away from the den, depositing the eggs they had consumed away in their own, subsequent bowel movements at an appropriate distance before the eggs had the chance to hatch into larvae and transmit the parasite to the pack.

Domestic dogs may just be enacting this behavior instinctively—only for them, there isn't as much danger of them picking up a parasite at home. However, the theory isn't foolproof. The surveys also found that so-called "greedy eaters" were more likely to eat feces than dogs who aren't quite so intense about food. So yes, it could still be about a poop-loving palate.

But really, it's much more pleasant to think about the behavior as a parasite-protection measure than our best pals foraging for a delicious fecal snack. 

[h/t The Washington Post]

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