This egg-laying mammal sheds heat in a curious way

() — The Australian echidna has developed a curious way of cooling itself: it blows bubbles with its beak-shaped snout.

The short-beaked echidna is common in Australia, Tasmania and New Guinea and, along with the platypus, is one of Earth’s few monotremes, that is, egg-laying mammals, and has existed for millions of years. With a long sticky tongue, a predilection for eating ants and termites, and a body covered in spineless quills, the echidna is also known as the spiny anteater.

The short-beaked echidna is native to Australia. Credit: Avalon/Universal Images Group Editorial/Getty Images

Despite being one of the oldest species in the world, the echidna is believed to be sensitive to heat. Previous research has suggested that a body temperature of 38°C and an air temperature of 35°C is lethal to the animal.

However, this unusual creature lives in extremely hot and arid regions of Australia, where its existence seems impossible.

Now, new research has shown how the short-beaked echidna has adapted to combat the heat, something that will become even more crucial as the world warms due to the climate crisis.

Scientists from Curtin University, Australia, used thermal vision cameras to investigate non-contact echidnas in the Dryandra Forest and Boyagin Nature Reserve, located about 170 kilometers southeast of Perth.

The researchers captured infrared images of 124 echidnas for 34 days over 12 months to record how they shed heat. academic journal Biology Letters published this Tuesday a study in which the results are detailed.

The researchers did not expect to find that echidnas blow mucus bubbles to regulate their internal temperatures.

“We have observed a number of fascinating methods used by echidnas to manage heat that allow the animal to be active at much higher temperatures than previously thought,” said study lead author Dr. Christine Cooper, Senior Lecturer. of the Curtin School of Molecular and Life Sciences, in a statement.

“Echidnas blow bubbles through their noses, which burst over the tip of their noses, moistening it. As it evaporates, the moisture cools their blood, meaning the tip of their nose functions as an evaporative window.”

The thermal data also showed that echidnas can lose heat through their undersides and feet, but can use their dorsal spines to retain body heat if necessary.

Thermal imaging helped the researchers determine how echidnas lose heat. Credit: Dr. Christine Cooper/Curtin University

The researchers were surprised to see that the echidnas were active despite the fact that the air temperature was several degrees above what is considered the “lethal” level for the animals.

In summer, echidnas adopt nocturnal behavior to escape the heat. But they have also been seen taking refuge inside hollow logs where the air temperature is well above its limit.

The latest findings suggest that previous estimates of the high temperatures echidnas can withstand were “underestimates,” according to the new study.

“Echidnas cannot pant, sweat or lick themselves to lose heat, so they could be affected by rising temperatures and our work shows alternative ways echidnas can lose heat, explaining how they can be active in warmer conditions than what was thought,” Cooper said.

“Understanding the thermal biology of echidnas is also important for predicting how they might respond to a warmer climate.”

Next, she and her colleagues want to model how much heat echidnas can give off to predict how they can withstand different environmental conditions and warming.

These resilient animals have proven to be more resilient to high temperatures than previously thought, but that doesn’t mean that rising temperatures don’t present a challenge for them, Cooper says.