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When Poachers Kill Their Mothers, Elephant Daughters Hold Social Networks Together

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In elephant families, it’s the matriarchs who call the shots. They decide where a group goes, where it eats and when. They’re also the glue that holds elephant societies together. Elephants have a tiered social network of small “core groups” of close relatives, and larger, less cohesive “bond groups” and “clan groups” that include distant relatives and acquaintances. Older matriarchs with lots of social ties are the hubs that connect all these groups to each other. 

These older female leaders are also frequent targets for ivory poachers because of their large tusks. When they’re killed, other elephants not only lose their mothers, sisters, and grandmothers, but also their links to the rest of their social networks. 

In other animal societies, studies have shown that removing individuals who act as social hubs can collapse such networks. With demand for ivory leading to tens of thousands of elephant deaths a year, researchers feared that the same thing would happen to elephants. A new study published in the journal Current Biology shows, though, that elephant societies are more resilient than expected because younger females step into their mothers’ connective roles in the social network. 

Biologists Shifra Goldenberg, Iain Douglas Hamilton, and George Wittemyer explored how elephant networks respond to the “selective knockouts” caused by poaching by looking at data they had collected while studying more than 100 elephants over the last 18 years in Kenya’s Samburu National Reserve. They knew many of the elephants by the shape of their ears, their scars and other body markings, and even their behavioral quirks. They also knew which elephants hung out together and how their different groups were connected. 

The researchers went back to their observations and reconstructed the Samburu elephants’ social network at different points between 1998 and 2014, during which there were stretches of relatively little poaching and a recent period of intense poaching. 

They found that over those 16 years, the average age of the Samburu elephants became much younger as older elephants were killed. There was a high turnover in the population’s adult females, and less than one-third of the elephants that the researchers encountered in 1998 were still alive last year.

Despite the death toll, the Samburu social network didn’t fall apart. It remained intact because daughter elephants stepped in to fill the roles that were left behind by their mothers. In some of these cases, the new matriarchs were barely fully grown, but their surviving relatives still rallied around them as the oldest females in the family.

These younger elephants not only took over the leadership of their core groups, but filled in the connective roles in the bigger network, often replicating the positions held by their mothers. Daughters maintained the social ties and relationships their mothers had built when they were alive, keeping their core group connected to the others in the bond group through matriarchs that their mothers had known, or their daughters if both moms had died. This helped them to keep the network intact with more or less the same structure that had existed before. When daughters couldn’t recreate their mothers’ networks exactly, they used the social opportunities that their mothers had provided them to strengthen relationships with elephants that were once only distant contacts of their moms, thus creating new bond groups.

The resilience of the elephants’ social structure is good news, but the researchers warn that there’s more work to be done before we know all the consequences of these families losing their oldest members. Even with the leadership roles filled and social ties maintained, elephants groups may run into problems with younger matriarchs in the lead. They lack the experience and knowledge that their mothers accrued over time, and other research has shown that older matriarchs are better than younger ones at distinguishing and responding to predators and other threats, and that families with older leaders have higher reproductive rates. The researchers plan to keep monitoring the Samburu elephants to see how these rebuilt families fare over time. 

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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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