Octopuses Change Colors to Intimidate Their Foes, Study Finds

Octopuses are well-known for being anti-social, but new research is proving they aren’t as reclusive as scientists previously believed. In fact, their knack for changing their appearance—long thought of as an effective way to hide—may also be a way they communicate with other octopuses, a new study finds. Research from Alaska Pacific University and the University of Sydney published in Current Biology indicates that the ability to change the hue of their bodies plays an important role in conflicts between octopuses.

The researchers studied a species called Octopus tetricus by setting up cameras in the shallow waters of Jervis Bay off the eastern coast of Australia. In more than 50 hours of video, they catalogued 186 octopus interactions, noticing a pattern in the social lives of the eight-tentacled creatures: They tend to turn dark colors when they feel aggressive.

The octopus in the background of the photo is adopting an aggressive posture, while the pale octopus in the foreground is being submissive.

When a dark-colored octopus approached another dark-colored octopus, the two were more likely to fight, whereas if a light-colored octopus met a dark octopus, the paler of the two was likely to scuttle off in retreat. Dark octopuses were more likely to stand their ground during a beef, while lighter octopuses were more likely to beat it.

In addition to dimming the color of their bodies, aggressive octopuses typically stand up tall and spread their web out in a position "nicknamed the Nosferatu pose,” making themselves look as large and forbidding as possible, while submissive octopuses will slink down.

This adds to previous research that found that octopuses can be social in captivity, even cohabitating in dens. The authors of the current study suggest that octopuses may behave more socially in areas where there’s a lot of food to be had, but limited places to hide. The growing body of evidence for octopus interactions (that don’t involve eating each other) “indicates that we should no longer consider octopuses as solitary and asocial,” they write.

[h/t: NPR]

All images by David Scheel

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iStock
Good News, Dog Parents: You Can Teach Puppies as Well as Their Canine Moms Can
iStock
iStock

If you’ve ever adopted a puppy, you probably know how frustrating it can be to teach your new family member the basic tenets of common decency, like not to pee on the carpet or tear up a whole roll of toilet paper.

In other areas, though, pups are rather impressive learners, capable of mimicking some human behaviors. In fact, for some tasks, they learn just as effectively from watching people as they do from watching other dogs, including their own mothers, a new study in Nature revealed.

Researchers from Hungary and the UK took 48 young puppies of various breeds and studied the conditions under which they can be taught to open a puzzle box containing food. The experiment revealed that the puppies were able to learn how to open the box regardless of whether the task was first demonstrated by a person, their mother, or an unfamiliar dog. In other words, not only are puppies capable of social learning, but they're able to learn tasks from humans they don't know—in this case, the experimenter.

However, researchers were surprised to learn that the puppies were more likely to learn how to open the box by watching an unfamiliar dog than by watching their own mothers. That may be because puppies spend more time looking at—and thus, learning from—an unfamiliar dog that intrigues them. This differs from other species such as kittens, which “learn to press a lever for food more rapidly from their mother than from an unfamiliar adult,” the study notes.

In addition, the puppies were able to perform the task again after a one-hour break, indicating that they had retained some memory of the learning experience.

The ability of dogs to learn from humans has been recorded in previous research. A 2015 study revealed that dogs learn better by demonstration (or the “do as I do” method) than training techniques that involve a system of punishments and rewards. The "do as I do" approach probably isn't the most practical method of teaching your pup to do its business outside, but if you already have an adult dog at home, your new puppy can follow the older dog's lead and learn by example.

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Michael Hutchinson
Spiders Can Fly Through the Air Using the Earth's Electric Field
A spider exhibiting ballooning behavior.
A spider exhibiting ballooning behavior.
Michael Hutchinson

Every so often, otherwise Earth-bound spiders take to the air. Ballooning spiders can travel hundreds of miles through the air (and, horrifyingly, rain down on unsuspecting towns). The common explanation for this phenomenon is that the spiders surf the wind on strands of silk, but there may be other forces at work, according to a new study spotted by The Atlantic.

In the research, published in Current Biology, University of Bristol scientists argue that Earth's atmospheric electricity allows spiders to become airborne even on windless days. To test their hypothesis, the researchers exposed spiders in the lab to electric fields similar to those naturally found in the atmosphere.

When the electric field was turned on, the spiders began to exhibit behavior associated with ballooning—they "tiptoed" on the ends of their legs, raised their abdomens, and released silk. Spiders only exhibit this behavior when ballooning. And when they did become airborne, the spiders’ altitude could be controlled by turning the electric field on and off. When the electric field was on, they rose through the air, but when it was off, they drifted downward.

This provides a potential explanation for why spiders take to the skies on certain days but not others, and how they can fly in calm, windless weather— something scientists have puzzled over since the early 19th century. (Even Darwin was flummoxed, calling it "inexplicable," The Atlantic notes.) However, the researchers note that these electric fields might not be totally necessary for ballooning—wind alone might work perfectly fine on some days, too. But understanding more about when and how spiders become airborne could help us predict when there will be large masses of arachnids flying through the skies (and hide).

[h/t The Atlantic]

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