Placeholder Image

Subtitles section Play video

  • As if koalas could be any more adorable than they already are, they tend to spend a lot

  • of their time hugging trees.

  • Now I get living in trees- that’s a good way to avoid predators since larger animals

  • usually can’t climb them.

  • But there's plenty of animals, like most monkeys, that live in trees, and they don’t feel

  • the need to hug them all the time.

  • And for a long time, zoologists weren’t sure why koalas felt the need to wrap themselves

  • around the tree so much.

  • And yeah maybe this doesn’t sound like the most pressing scientific question, but according

  • to a new research study, theyre actually hugging the trees to stay cool.

  • Australia is not one of the most hospitable of places to live. It’s really hot a lot

  • of the time, there’s not much water around, and food can be hard to come by.

  • So koalas have to keep cool somehow, but they have a big problem: they don’t sweat.

  • Now, koalas aren’t the only animals that can’t sweat. Dogs, for instance, can only

  • sweat through the parts of their bodies that aren’t covered in fur.

  • To keep cool, dogs lick their noses and pant. Kangaroos do the same thing, they lick their

  • forearms. The extra heat they lose through the moisture cooling on their skin is usually

  • enough to regulate their body temperatures.

  • But when it gets unusually hot and there isn’t much rain, koalas would rather not lick themselves

  • or pant, because they’d get dehydrated too quickly. And when you live in a tree, water

  • can be hard to come by. Climbing down to find water would expose them to predators, so they

  • don’t want to do that.

  • In fact, koalas don’t normally drink very much; instead, they usually get all the water

  • they need from the eucalyptus leaves they eat.

  • By hugging trees, though, koalas can stay cool without losing water.

  • When researchers took infrared pictures of the koalas hugging trees, they realized that

  • the trees are, on average, about five degrees cooler than the surrounding air.

  • Theyre not sure why the trees are so much cooler, but they think it might have something

  • to do with the groundwater the trees pull up through their trunks.

  • But it might also just take longer for the trees to heat up after the cool of the night.

  • By spreading as much of their bodies as possible against the trees, koalas are able to transfer

  • away some of their heat, and can cool themselves down by as much as 68 percent.

  • So yeah, hugging trees is adorablealso useful.

  • Thank you for watching this SciShow Quick Question, and especially thank you to 7-year-old

  • Zahava from Minnesota who suggested this topic. If you have questions you would like answered,

  • you can find us on facebook, tumblr, and twitter and, of course, in the comments below.

  • And if you want to keep getting smarter with us, just go to and subscribe.

As if koalas could be any more adorable than they already are, they tend to spend a lot

Subtitles and vocabulary

Operation of videos Adjust the video here to display the subtitles

B1 US hugging lick stay cool sweat water pant

Why Do Koalas Hug Trees?

  • 176 7
    Eating posted on 2015/02/24
Video vocabulary