Snot bubbles and belly flops keep echidnas cool, research finds

Echidnas blow snot bubbles and do belly flops to keep themselves cool in the Australian heat, new research has found.

The native animals are believed to less tolerant to hot weather than other Australian species.

Their spines act like a blanket, and the animals cannot pant, sweat or lick themselves to cool down.

But thanks to infrared cameras, researchers have now discovered unique methods they use to release heat.

Echidnas have long been known to blow bubbles of mucus out their noses, but it was believed this was primarily to clear dirt and dust from their nasal passages.

The thermal imaging captured by zoologist Christine Cooper and her team indicates otherwise.

The mucus bubbles burst and wet the tip of the echidna's snout, allowing evaporation to cool blood just under the skin. That cooler blood then circulates through their body, helping keep the animal's temperature down.

The researchers also discovered that the echidnas shed heat by pressing their bellies and legs - which are spineless - to cooler surfaces.

"We observed a number of fascinating methods used by echidnas to manage heat and which allow the animal to be active at much higher temperatures than previously thought," Dr Cooper said.

Echidnas are one of the rarest species in the world, one of only two types of monotreme - mammals that lay eggs - and Dr Cooper says understanding how they tolerate heat is essential for conservation on a warming planet.