January 18, 2023

A short-beaked echidna (Tachyglossus aculeatus).
Image credit: Shutterstock
Just when we thought these iconic Australian creatures couldn’t get any quirkier, it turns out they’re using their own slime to beat the heat, new research has found.
Echidnas. They like to swim, their hind feet point backwards, they lay their eggs in a pseudo-pouch, they can go into a temporary hibernation-like state to conserve energy, they can dig vertically, shoulder breathe through their skin, and the men even have a forty penis.
And now another strange property has been discovered.
For a long time, we’ve known that echidnas don’t sweat, pant, or lick—actions that other animals do to keep their bodies cool.
But these monotremes have impressive thermal tolerance. How they do it has perplexed the scientific community for years.
Now we finally know the answer. Turns out they keep cool by blowing mucus bubbles through their beaks.
It’s not glamorous but it works.
dr Christine Cooper from Curtin University’s School of Molecular and Life Sciences explained:
“Echidnas blow bubbles from the nose that burst over the tip of the nose and get wet. As the moisture evaporates cools their blood, that is, the tip of their nose acts as an evaporation window.
This behavior was discovered using thermal imaging cameras.
A group of wild short-necked echidnas were filmed in a patch of bushland about 170km south-west of Perth.
The film was then studied to show how the animals exchange heat with their environment.
And it doesn’t stop at the snow. Echidnas also have other cooling techniques that allow them to be active at much higher temperatures than previously thought, says Dr Cooper.
“We also found that their spines provide flexible insulation to retain body heat, and they can lose heat from spineless areas on their undersides and legs, meaning these areas act as thermal windows that allow heat exchange.”
Dr. Cooper adds that understanding the thermal biology of echidnas is also important for predicting how they might respond to climate change and a warming environment.
These findings were published in Biology Letters, titled ‘Postural, pilo-erective and evaporative thermal windows of the short-beaked echidna’.
The research was funded by an Australian Research Council (ARC) Discovery Grant.
