Echidnas blow bubbles of snot to keep cool

Scientists have discovered that echidnas blow snot bubbles to keep themselves cool in the hot weather.

“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,” said Curtin University zoologist Dr Christine Cooper.

“Echidnas blow bubbles from their nose, which burst over the nose tip and wet it. As the moisture evaporates it cools their blood, meaning their nose tip works as an evaporative window.”

Using infrared thermography, the researchers analysed which body parts of the short-beaked echidna (Tachyglossus aculeatus) are insulating and which they can lose heat from. 

“Echidnas can’t pant, sweat or lick to lose heat, so they could be impacted by increasing temperature and our work shows alternative ways that echidnas can lose heat, explaining how they can be active under hotter conditions than previously thought,” said Cooper.

“We also found their spines provide flexible insulation to retain body heat, and they can lose heat from the spineless areas on their underside and legs, meaning these areas work as thermal windows that allow heat exchange.”

You can see this in the video. Their nose is almost black, in the paper the researchers suggest functions like a ‘wet bulb globe thermometer’. This is a thermometer covered in a wet cloth. As water evaporates from a cloth, the evaporation cools the thermometer – this is also what’s happening with the echidna’s snotty nose.

“These avenues of heat exchange likely contribute to the higher-than-expected thermal tolerance of this species,” the researchers write in their new paper.

Another set of researchers from the University of Adelaide had seen this snot blowing behaviour before, after citizen scientists had sent in photos to the echidna conservation EchidnaCSI app.

“There’s a video that we got sent of an echidna blowing snot balls,” says Dr Tahlia Perry, creator of EchidnaCSI.

“Echidnas are so hard to find out in the wild. If we were to go out just as researchers and try and get this stuff on video, it would take decades.”

If you want to get involved in EchidnaCSI you can check out more information about it here.

The research has been published in Biology Letters.