Blowing bubbles? Echnidas' strange superpower against climate change

“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,” she said.

“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,” also added.

As per NSW National Parks and Wildlife Service, extreme temperatures are not tolerated by echidnas, so they seek shelter in caves and rock crevices.

“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," Dr Cooper added.

Climate change and echidnas

It is well known that a sizeable "blood sinus," or reservoir of blood that collects towards the surface, exists in the echidna's beak. Theoretically, a burst bubble that leaves a mucus coating may take heat from the blood and dissipate, keeping the echidna cold.

Cooper chose to put this intriguing theory to the test in the real world, as reported by LiveScience.

“Understanding the thermal biology of echidnas is also important to predict how they might respond to a warming climate,” Dr. Cooper said.

“Our work highlights how technological advances that allow for non-contact study of animal physiology, such as the thermal vision used in this study, can give us a better understanding of the physiological capacity of animals in their natural environment.”

The study was published in Biology Letters on December 17, 2022.

More about echidnas

Echidnas are solitary, medium-sized creatures with coarse fur and spines. The spines are modified hairs that are constructed of the same fibrous protein known as keratin, which also gives animals their fur, claws, nails, and horn sheaths.

Echidnas are powerful diggers with short, sturdy limbs and huge claws. To aid in digging, their hind limb claws are long and bent backwards. Echidnas have small, toothless mouths.

Echidnas consume food by tearing up soft logs, anthills, and other similar structures. It then collects prey with its long, sticky tongue that extends from its snout. Echidnas also have the second-lowest active body temperature of any animal.

Study abstract:

We identify for wild, free-living short-beaked echidnas (Tachyglossus aculeatus) a novel evaporative window, along with thermal windows, and demonstrate the insulating properties of the spines, using infrared thermography. The moist tip of their beak, with an underlying blood sinus, functions as a wet bulb globe thermometer, maximizing evaporative heat loss via an evaporative window. The ventral surface and insides of the legs are poorly insulated sites that act as postural thermal windows, while the spines provide flexible insulation (depending on piloerection). These avenues of heat exchange likely contribute to the higher-than-expected thermal tolerance of this species. Our study highlights how technological advances that allow for non-contact measurement of thermal variables allow us to better understand the physiological capacity of animals in their natural environment.