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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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Whale Sharks Can Live for More Than a Century, Study Finds
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Some whale sharks alive today have been swimming around since the Gilded Age. The animals—the largest fish in the ocean—can live as long as 130 years, according to a new study in the journal Marine and Freshwater Research. To give you an idea of how long that is, in 1888, Grover Cleveland was finishing up his first presidential term, Thomas Edison had just started selling his first light bulbs, and the U.S. only had 38 states.

To determine whale sharks' longevity, researchers from the Nova Southeastern University in Florida and the Maldives Whale Shark Research Program tracked male sharks around South Ari Atoll in the Maldives over the course of 10 years, calculating their sizes as they came back to the area over and over again. The scientists identified sharks that returned to the atoll every few years by their distinctive spot patterns, estimating their body lengths with lasers, tape, and visually to try to get the most accurate idea of their sizes.

Using these measurements and data on whale shark growth patterns, the researchers were able to determine that male whale sharks tend to reach maturity around 25 years old and live until they’re about 130 years old. During those decades, they reach an average length of 61.7 feet—about as long as a bowling lane.

While whale sharks are known as gentle giants, they’re difficult to study, and scientists still don’t know a ton about them. They’re considered endangered, making any information we can gather about them important. And this is the first time scientists have been able to accurately measure live, swimming whale sharks.

“Up to now, such aging and growth research has required obtaining vertebrae from dead whale sharks and counting growth rings, analogous to counting tree rings, to determine age,” first author Cameron Perry said in a press statement. ”Our work shows that we can obtain age and growth information without relying on dead sharks captured in fisheries. That is a big deal.”

Though whale sharks appear to be quite long-lived, their lifespan is short compared to the Greenland shark's—in 2016, researchers reported they may live for 400 years. 

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Animal Welfare Groups Are Building a Database of Every Cat in Washington, D.C.
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There are a lot of cats in Washington, D.C. They live in parks, backyards, side streets, and people's homes. Exactly how many there are is the question a new conservation project wants to answer. DC Cat Count, a collaboration between Humane Rescue Alliance, the Humane Society, PetSmart Charities, and the Smithsonian Conservation Biology Institute, aims to tally every cat in the city—even house pets, The New York Times reports.

Cities tend to support thriving feral cat populations, and that's a problem for animal conservationists. If a feline is born and grows up without human contact, it will never be a suitable house cat. The only options animal control officials have are to euthanize strays or trap and sterilize them, and release them back where they were found. If neither action is taken, it's the smaller animals that belong in the wild who suffer. Cats are invasive predators, and each year they kill billions of birds in the U.S. alone.

Before animal welfare experts and wildlife scientists can tackle this problem, they need to understand how big it is. Over the next three years, DC Cat Count will use various methods to track D.C.'s cats and build a feline database for the city. Sixty outdoor camera traps will capture images of passing cats, relying on infrared technology to sense them most of the time.

Citizens are being asked to help as well. An app is currently being developed that will allow users to snap photos of any cats they see, including their own pets. The team also plans to study the different ways these cats interact with their environments, like how much time pets spend indoors versus outdoors, for example. The initiative has a $1.5 million budget to spend on collecting data.

By the end of the project, the team hopes to have the tools both conservationists and animal welfare groups need to better control the local cat population.

Lisa LaFontaine, president and CEO of the Humane Rescue Alliance, said in a statement, “The reality is that those in the fields of welfare, ecology, conservation, and sheltering have a common long-term goal of fewer free-roaming cats on the landscape. This joint effort will provide scientific management programs to help achieve that goal, locally and nationally."

[h/t The New York Times]

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