10 Things You Didn’t Know About Koalas
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.