Science

Climate change is turning koalas to drink, scientists find

Koala
Scientists say climate change is turning koalas to drink. Source: Supplied

Climate change is forcing koalas to seek alternate water sources, including troughs on the ground out of the safety of the trees, scientists have found.

The drinking habits of Australia's koalas may indicate climate change is starting to bite, a new study has found.

Researchers have used video cameras to observe more than 100 koalas drinking from purpose-built water stations near Gunnedah in north-east NSW for the first time.

The water troughs were set up on the ground and in trees for six months last year.

The scientists behind the study say the behaviour is unusual because koalas usually subsist on a diet of eucalyptus leaves, which are thought to provide all the nourishment they need.

“We found not only that they drank extensively, but visits to the artificial stations depended on rainfall,” Dr Valentina Mella, the study’s lead researcher, said.

“This suggest the leaves they are eating are not providing them with enough water.”

The study, conducted by researchers from the University of Sydney, set up 10 paired ground and tree water stations on a private farm of 2100 hectares.

Video cameras were mounted above the drinking stations to record the koalas’ behaviour.

Scientists found the koalas visited the stations 193 times between April and September, with 132 koalas drinking the supplied water.

The animals not only drank in the safety of tree tops, but also on the ground during the day, when they would normally be asleep, according to the study.

Dr Mella said the results clearly showed climate change posed a threat to the animals.

“With climate change, leaves became tougher, less moist, have higher concentration of toxins and have less nourishment,” she said. “It's a huge problem.”

Rising global temperatures, as well as an increase in atmospheric CO2 concentration, are expected to have significant impacts upon the palatability and nutritional quality of the koala’s food supply.

More regular heatwaves and droughts will also mean less free water is available for the animals and create conditions for destructive bushfires.

Valentina Mella
A koala joey with University of Sydney researcher Valentina Mella. (University of Sydney)
Supplied

Koalas are already under pressure in Australia due to habitat loss, disease, dog attacks and collisions with vehicles.

In April 2012, they were classified as vulnerable under Australian law because their population was declining rapidly in NSW, Queensland and the ACT.

Dr Mella said the study is ongoing and she hoped the findings would help create a practical plan to manage the habitat of the iconic species.

“The message that I want to send is that the koalas are telling us that climate change is affecting them,” she said.

“There is the possibility that free water might be one of the tools that can help them deal with climate change.”