Large trees had their own protective “microclimate”, which is likely to become increasingly important to tree-dwelling creatures like koalas if global temperatures continue to increase as predicted” said Dr Kearney.
A study published in Royal Society journal Biology Letters has revealed hugging trees help koalas to keep cool. Scientists used thermal cameras to reveal that, in hotter weather, the animals moved to the lower, cooler parts of the trees.
A thermographic camera is a device that forms an image using infrared radiation, similar to a common camera that forms an image using visible light. Instead of the 450–750 nanometer range of the visible light camera, infrared cameras operate inwavelengths as long as 14,000 nm.
They also pressed their bodies even closer to the trunks.
The team, led by researchers from the University of Melbourne, was studing how koalas regulated their temperature.
This is a part of a wider research project investigating the effect of climate on land-dwelling animals in Australia, a country which experienced an extreme heat wave earlier this year.
while PhD student Natalie Briscoe was studing the koalas’ behaviour, she noticed that in the winter the animals would stay high in the trees-up near the leaves feeding.
In the hotter summer weather though, they would move down.
Dr. Micheal Kearney from the University of Melbourne explained:”They’d just flop over the lower tree trunks.
“It looked like they were spread-eagled and uncomfortable; it seemed like the wrong thing to do.”
But measurements of the temperatures of the tree trunks showed that, on days as hot as 39C, they were up to seven degrees cooler than the air.
Research Dr Welbergen published earlier this year revealed the effects on wildlife of such extreme events. His research revealed that 45,500 flying foxes had died on just one extremely hot day in southeast Queensland.
“Our thermal video shows group of flying-foxes trying to cope with an extreme heat event by distributing saliva on their wings,” he explained.
Hugging trees, Dr Kearney said, helps the koalas to avoid similar water loss – enabling them to “dump heat” into the tree and to avoid panting.