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Flickr user Rocky via Wikimedia Commons // CC-BY-2.0
Flickr user Rocky via Wikimedia Commons // CC-BY-2.0

Norwegian Eagles Are Taking Out Full-Grown Reindeer

Flickr user Rocky via Wikimedia Commons // CC-BY-2.0
Flickr user Rocky via Wikimedia Commons // CC-BY-2.0

Here’s a reindeer story you may not want to tell the kids: Golden eagles have been spotted attacking full-grown reindeer in Norway.

The golden eagle (Aquila chrysaetos) is a pretty tough bird. With a wingspan up to 7.5 feet and a diving speed of more than 150 miles per hour, A. chrysaetos is generally pretty good at getting what it wants. That usually means rabbits, hares, birds, and squirrels. But when the pickings are slim, golden eagles will get a little more ambitious, going after sheep, saiga antelope, and even wolves. Researchers even saw one brazen bird carrying off a bear cub.

So the idea that these birds are preying on reindeer is not quite as ridiculous as it sounds. It was a fact well known by the reindeer-herding Sami people of Finland, who had complained of the attacks for years. But scientists, being scientists, were still having a hard time believing it in the absence of evidence.

Then in 2009, researcher Harri Norberg of the Finnish Wildlife Agency took a closer look at the carcasses of reindeer calves. The forensic evidence showed that the majority of them had indeed fallen prey to golden eagles. Not too long after, a BBC film crew captured a handful of attacks on camera. The reality was not pretty.

An attacking eagle drops out of the sky above its prey, and then drives its talons into the reindeer’s body, puncturing large blood vessels.

"They are not killing anything instantly, so they have to ride like a rodeo cowboy on the back of the calf," film producer Ted Oakes told the BBC. After that, it’s just a matter of waiting for the reindeer to bleed out.

Norberg and Oakes suspected that the reindeer calves were not the eagles’ only victims, but, once again, they had no proof. 

Six years later, a Norwegian naturalist has seen it for himself. Olav Strand of the Norwegian Institute for Nature Research told New Scientist that he has seen golden eagles kill adult reindeer weighing more than 130 pounds.

Strand believes the attacks are an indirect consequence of human activity. Harsher winters—a result of climate change—are making small prey like hares harder to come by. At the same time, human settlements are shrinking available reindeer territory, driving the animals into a smaller area, where they can be more easily picked off. "It’s possible to expect some kind of interaction between the level of fragmentation and the coming climate change," he told New Scientist. "Through history, the only defense reindeers have had to climate and predators has been to move."

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NUS Environmental Research Institute, Subnero
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Researchers in Singapore Deploy Robot Swans to Test Water Quality
NUS Environmental Research Institute, Subnero
NUS Environmental Research Institute, Subnero

There's something peculiar about the new swans floating around reservoirs in Singapore. They drift across the water like normal birds, but upon closer inspection, onlookers will find they're not birds at all: They're cleverly disguised robots designed to test the quality of the city's water.

As Dezeen reports, the high-tech waterfowl, dubbed NUSwan (New Smart Water Assessment Network), are the work of researchers at the National University of Singapore [PDF]. The team invented the devices as a way to tackle the challenges of maintaining an urban water source. "Water bodies are exposed to varying sources of pollutants from urban run-offs and industries," they write in a statement. "Several methods and protocols in monitoring pollutants are already in place. However, the boundaries of extensive assessment for the water bodies are limited by labor intensive and resource exhaustive methods."

By building water assessment technology into a plastic swan, they're able to analyze the quality of the reservoirs cheaply and discreetly. Sensors on the robots' undersides measure factors like dissolved oxygen and chlorophyll levels. The swans wirelessly transmit whatever data they collect to the command center on land, and based on what they send, human pilots can remotely tweak the robots' performance in real time. The hope is that the simple, adaptable technology will allow researchers to take smarter samples and better understand the impact of the reservoir's micro-ecosystem on water quality.

Man placing robotic swan in water.
NUS Environmental Research Institute, Subnero

This isn't the first time humans have used robots disguised as animals as tools for studying nature. Check out this clip from the BBC series Spy in the Wild for an idea of just how realistic these robots can get.

[h/t Dezeen]

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iStock
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There May Be an Ancient Reason Why Your Dog Eats Poop
iStock
iStock

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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