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10 Things You Didn’t Know About Koalas

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Sure, they're cute, and they certainly look cuddly. But here are a few other, more surprising things you might not have known about koalas.

1. Koalas hug trees to keep cool. Scientists used thermal cameras to watch some koalas hanging out in trees and saw that when the weather was warm, the animals moved to lower parts of the trees and pressed themselves close to the trunks, wedging their bottoms right into the coolest spots.

2. In captivity, koalas exhibit more lesbian behavior than straight. Sexual encounters have been known to involve up to five females. They last twice as long as heterosexual encounters.

3. Fifty to 90 percent of female koalas have chlamydia. The symptoms in koalas are chest infections, conjunctivitis, and "wet-bottom," which looks like what you’d imagine. It can be fatal unless treated with antibiotics and can leave the koalas sterile. Here's the catch: Predators aren’t that important to koala population control, but chlamydia might be. In the late '90s, chlamydia-free koalas were introduced into Mount Eccles National Park in Victoria, which had a huge Manna Gum tree population. Without chlamydia to control the population, koala numbers doubled every few years, and thousands of hectares of forest were at threat until hormonal contraception was introduced. In other areas where chlamydia-free koalas were introduced, the koalas killed the trees and then died of starvation [PDF]. When koalas are stressed, chlamydia—which is normally harmless—limits the population growth. Now, rather than overpopulation, a combination of habitat loss and a retrovirus is making chlamydia a problem even as the population dwindles.

4. Koalas fingerprints are virtually indistinguishable from human ones, so much so that they can be mistaken for one another in criminal investigations. The animals' hands are covered in warts.

5.  Although koalas eat around half a kilogram of eucalyptus leaves a day, they’re very picky, tending to choose around 30 of the 600 varieties of eucalyptus trees out there. Koalas prefer large trees, but avoid those with low protein content and nauseating toxins. The problem is that two trees of the same species right next to each other can have wildly different toxin levels, forcing the koala to rely on their smell. Eucalyptus leaves are very low in calcium, forcing the koalas to go to the ground and eat dirt. They are reported to smell like big cough drops because of all that eucalyptus.

6. Because of their diet koalas have an unusually large caecum—part of the digestive system—to help them digest their diet of eucalyptus leaves. On the other hand, they have tiny brains because brains use a lot of energy and their diets don’t give them much to work with. They can only stay awake for four hours a day.

7. Koala joeys feed on their mother’s "pap," which is a kind of soup the koalas make internally and excrete—so yes, baby koalas eat their mother’s droppings. They're full of microorganisms and get their tiny digestive tracts ready for a lifetime of leaves for lunch.

8. The anima's scientific name, Phascolarctos cinereus, loosely means "ash-grey pocket-bear," but koalas are not bears: They’re marsupials. Their closest living relative is the wombat.

9. Some people might tell you that "koala" means "don’t drink"; don’t believe them. When koalas get really thirsty they do what any intelligent animal would do and drink from streams or swimming pools. According Etymology Online, koala comes from the Dharuk name for animal, which has been given in different ways including koola, kulla, and kula.

10. Mick is an incredibly rare white koala with white fur and dark eyes and nose. Albino koalas are white with pink eyes and noses.

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This High-Tech Material Can Change Shape Like an Octopus
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Octopuses can do some pretty amazing things with their skin, like “see” light, resist the pull of their own sticky suction cups, and blend in seamlessly with their surroundings. That last part now has the U.S. Army interested, as Co.Design reports. The military branch’s research office has funded the development a new type of morphing material that works like an octopus’s dynamic skin.

The skin of an octopus is covered in small, muscular bumps called papillae that allow them to change textures in a fraction of a second. Using this mechanism, octopuses can mimic coral, rocks, and even other animals. The new government-funded research—conducted by scientists at Cornell University—produced a device that works using a similar principle.

“Technologies that use stretchable materials are increasingly important, yet we are unable to control how they stretch with much more sophistication than inflating balloons,” the scientists write in their study, recently published in the journal Science. “Nature, however, demonstrates remarkable control of stretchable surfaces.”

The membrane of the stretchy, silicone material lays flat most of the time, but when it’s inflated with air, it can morph to form almost any 3D shape. So far, the technology has been used to imitate rocks and plants.

You can see the synthetic skin transform from a two-dimensional pad to 3D models of objects in the video below:

It’s easy to see how this feature could be used in military gear. A soldier’s suit made from material like this could theoretically provide custom camouflage for any environment in an instant. Like a lot of military technology, it could also be useful in civilian life down the road. Co.Design writer Jesus Diaz brings up examples like buttons that appear on a car's dashboard only when you need them, or a mixing bowl that rises from the surface of the kitchen counter while you're cooking.

Even if we can mimic the camouflage capabilities of cephalopods, though, other impressive superpowers, like controlling thousands of powerful suction cups or squeezing through spaces the size of a cherry tomato, are still the sole domain of the octopus. For now.

[h/t Co.Design]

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Animals
25 Benefits of Adopting a Rescue Dog
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According to the ASPCA, 3.3 million dogs enter shelters each year in the United States. Although that number has gone down since 2011 (from 3.9 million) there are still millions of dogs waiting in shelters for a forever home. October is Adopt a Shelter Dog Month; here are 25 benefits of adopting a shelter dog.

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