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For ages, koalas and eucalyptus trees have gone hand-in-hand. These Australian marsupials have long been known to rarely leave these trees, which provide them with shelter and their only food, in the form of the trees' leaves.
In fact, they famously never even leave them to come down for a drink. This led biologists to guess that they got all their water from the moisture contained inside the leaves.
And this is still probably true for the most part. But a new study observing 13 years of wild behaviour says that these animals have another go-to beverage.
Koalas lick trees.
In case you're wondering how this works: No, eucalyptus trees don't ooze H2O. Instead, the behaviour happens when it rains.
The study states: "Koalas were observed licking the water running down the trunk of trees during, or immediately after, a rain event." Rain event. Sounds so official and important!
But for a koala it is a big deal, especially in a country as dry as Australia. An opportunity for a good healthy drink without having to leave the safety of the tree is clearly not one that these animals will pass up.
Researchers reported watching koalas continuously lapping up the water trickling down tree trunks for 15 minutes, 30 minutes, even longer.
Wild, not in captivity
Most importantly, this behaviour happened in the wild—under normal conditions and without human intervention.
After all, we have seen koalas take drinks before from dishes, bird baths, and water bottles. But these animals were either extremely desperate (due to drought or bushfires), or conditioned to feel safer in a habitat without predators (like a zoo or sanctuary). That is not everyday life.
This study, however, patiently observed wild behaviour over many years. After looking at the results, these scientists have concluded that koalas lick trees often and regularly. It's not unusual. It's just an activity that we missed noticing before now.
Which is encouraging for any of you budding biologists who worry that there's nothing left to discover. Even in an iconic animal like the koala, a thing as simple as how it gets a drink can still be a mystery waiting to be solved.
Drink on, thirsty koalas!
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