Iconic Aust'n lizard drinks water by digging itself in wet sand: scientists

Scientists have solved the 40-year old mystery of how one of Australia's best-known reptiles, the Thorny Devil, stays hydrated in the country's driest deserts.

Researchers from the University of Western Australia found that the lizards ingest most of their water by burying themselves in damp sand and using the channels in their scales to draw the moisture towards their mouths.

Philip Withers, the lead author of the study published in the Journal of Experimental Biology on Thursday, said the reptile's unique skin formation was critical to its survival.

"Clearly, it's important for them -- this special system has evolved and it's really quite bizarre," Withers told the Australian Broadcasting Corporation on Thursday.

"I think it might be more important for the extreme circumstances. You get a little bit of rain and the sand gets wet, and then it's really important to be able to suck the water out of the sand."

The Thorny Devil, which earned its name because of the conical spines that covers its body, has a mouth designed specifically to feed on small ants that share their habitat and are thus unable to suck water from the sand without the help of their skin.

Withers' team analyzed the lizard's drinking habits by placing the reptile on wet sand but when standing on the surface of the sand the capillaries in the skin filled only 59 percent and the lizard was unable to drink.

"They can certainly stand in a puddle of water and suck it up and drink it," Withers said.

"But they can't just stand on moist sand and suck it up and drink it. They can absorb some water that way, but it's not enough to fill the capillary channels.

"So if they want to get the water out of moist sand they have to do something extra.

"And it seems that what they do extra is to shovel it on top of themselves, and get gravity to help. And then it works." Endit