How koalas quench thirst

SCIENTISTS have solved a lingering mystery about koala behaviour – how these tree-dwelling marsupials native to Australia (澳洲) consume enough water to live.

A new study describes koala drinking behaviour in the wild for the first time, finding that they lick water running down the smooth surface of tree trunks during rainfall – a phenomenon called ‘stemflow’ – and do not rely merely on the water content of the leaves that make up their diet.

The findings, which the researchers said may be useful in koala conservation efforts, were based on 46 observations of koalas in the wild from 2006 to 2019, mostly at You Yangs Regional Park.

“I think the main message is that behavioural observations in the wild are very important to establish what is normal and what is unusual,” said ethologist Valentina Mella, lead author of the research.

Koalas, which are not bears despite a common misconception, spend most of their lives high up in eucalyptus trees. They rely on a diet of eucalyptus leaves, normally consuming around 500 to 800 grams daily.

The word Koala is thought to have meant ‘no drink’ in an Australian Aboriginal language. The question of their water consumption had long been puzzling. Koalas have been alleged to never drink free water in the wild, or to drink only occasionally.

They sleep about 20 hours a day to conserve energy because their diet requires a lot of energy to digest.

Koalas actually spend 98 percent of their lives in trees and the only time they are on the ground is when they are trying to find another tree with a more generous food supply or a mate.

(This article is published on Junior Standard on 19 May 2020)

Koala – National Geographic


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