Recent research by Charles Sturt University has found the common ringtail possum deals with the hot Australian climate by letting its body temperature rise to conserve water and lower its risk of dehydration.
The study by Dr James Turner—which is published in the Journal of Experimental Biology— recorded the oxygen consumption, carbon dioxide production and water loss of 10 ringtail possums when they were exposed to simulated heatwaves inside a respirometry system.
Dr Turner found that during heatwaves where the temperature rises from 30 to 38 degrees Celsius, the ringtail possum can conserve up to 9.6 millilitres of water every hour by allowing its body temperature to rise by three degrees Celsius.
“My study found that rather than losing large amounts of water to maintain a constant body temperature as the mercury rose, the ringtail possum allows its body temperature to rise during heatwaves and remain warmer than its surroundings,” Dr Turner said.
“When exposed to temperatures up to 38 degrees Celsius, the possums’ body temperature would begin to rise from 36 degrees Celsius to almost 39 degrees Celsius.
“Although humans would feel unwell with rising body temperatures, for possums, this survival strategy allows them to remain warmer than their surroundings, letting them continue to lose heat to the slightly cooler air and conserve more water.”
Dr Turner said the survival strategy does allow the native marsupial to lower its risk of dehydration, but this is only effective to a certain degree.
“I found that when the temperature exceeds around 35 to 36 degrees Celsius, the possums begin losing water when actively cooling by licking their fur, thereby increasing evaporative water loss and thermal conductance.
“When the air temperature reaches 39 degree Celsius, possums are at risk of feeling the negative effects of dehydration in less than 20 hours.
“Heatwaves negatively impact wildlife populations and their effects are predicted to worsen with ongoing global warming,” Dr Turner added.
“We need to improve our understanding of animal responses to environmental heat to aid conservation efforts and protect wildlife.”
The original version of this article can be read on the Charles Sturt University News website.