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Walter Siegmund via Wikimedia Commons // CC BY 2.5
Walter Siegmund via Wikimedia Commons // CC BY 2.5

Crows Form, Nurse, and Share Grudges Against People

Walter Siegmund via Wikimedia Commons // CC BY 2.5
Walter Siegmund via Wikimedia Commons // CC BY 2.5

Consider this a friendly reminder not to antagonize crows: According to a 2011 study in Proceedings of the Royal Society B, American crows remember the faces of people who wrong them, and enlist other birds to attack the offenders.

When it comes to intelligence, birds get no respect. For a long time, scientists assumed birds were stupid because their brains had significant differences from ours. But recent studies on bird brains and abilities are putting those fallacies in their place. Researchers have found sophisticated behavior in birds from finches and pigeons to Antarctic gulls. But there’s one group of birds that consistently amazes: crows and ravens.

Within the last 10 years we’ve learned that crows can make, store, and care for tools. They can count and exercise self-restraint. They can use bait to catch fish. They can certainly play. And, the authors of the Royal Proceedings study say, they can nurse some serious grudges.

Researchers at the University of Washington’s School of Forest Resources bought two masks that looked like human faces. A caveman-looking mask was designated the “dangerous” mask, while a Dick Cheney mask was “neutral.” They then visited wild crows at five sites around Seattle. At each site, the person wearing the caveman mask would approach the crows, trapped a few, banded their legs, and set them free—an experience the birds did not enjoy. As soon as the researcher let them go, the birds began yelling at their captor with a harsh, aggressive cry called “scolding.”

The sounds of conflict attracted more birds, which joined in scolding and attacking the researcher, even though they’d never met. “The mob of two to 15 birds hounds us, sometimes diving from the sky to within a few meters or less. This pursuit lasts about 100 meters (328 feet) as we walk away,” crow expert John Marzluff told Discovery News.

The Dick Cheney mask did not elicit a response.

Marzluff and his colleagues then traveled to other crow territories. The sight of the caveman mask caused an immediate ruckus among these crows—even though none of them had ever been caught or banded. Crows up to a mile away from the original site had heard about this no-good caveman guy, and they knew he was trouble when he walked in.

The grudge didn’t wear off, either. Marzluff said return trips in the caveman mask provoked the same hostile response, even five years later. He told Discovery News, "Individual crows that are adults can live 15-40 years in the wild (most die when young, but those that make it to adulthood can live a long time) and they probably remember important associations they have formed for much of their lives."

These associations aren't all negative. An 8-year-old girl, also in Seattle, made news last year when her family revealed that local crows had pretty much made her their queen.

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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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