People are exposed to fluorine in several different forms. What happens to fluoride in your body?Īll the important intake of fluorine is by mouth. "The easiest way to find them is to see them when they're walking across a road, because they just show up then like nothing," Professor Withers said.Question Suivante 2. He said the best place to spot one was on a road. And sometimes it's so hard to even find it." You can walk out there and you hear the radio going beep, beep, beep, and you know it's within a metre or so. It's truly amazing," Professor Withers said. "Their colouration, you can stand on one of these things and not even see it's there. Its mottled brown and yellow skin helps it blend in with the dirt and sand of its habitat. The other defence mechanism the thorny devil has is its colouring. This makes the devil a stationary target for would-be predators, who are warded off by the spikes that make the lizards difficult to eat. The slow-moving lizard sits on ant trails to feed, picking off ants one by one with its tongue as they walk by. The thorny devil is spiked as a form of defence against predators. Thorny devils are easy to spot when they cross roads ( Flickr: eyeweed) "So maybe it's just for when it's really hot and dry, a long drought or something and there's a bit of rainfall - they can harvest it." The thorny devil's suit of armour "I would think that a normal desert lizard can survive in the desert eating ants, without all of this stuff," he said. Professor Withers thinks the mechanism isn't necessary for the day-to-day survival of the lizard but may be useful in lengthy periods where there is little or no rainfall. Gravity, they suggest, gives the process a helping hand.Īnd while they haven't yet measured the results of shovelled sand on live lizards, they believe all the signs point to this self-burial in damp sand as the behaviour that allows devils to fill their capillaries and drink.īy piling it onto their backs, the thorny devils maximise the surface area of their skin touching the sand - as well as getting gravity's help in sucking the moisture from it. Using replica models of the lizard's skin, the scientists showed that piling sand on top of this unusual surface boosted the amount of moisture that could be sucked into capillary channels. Thorny devils have been observed sand-shovelling after periods of rain. And then it works." How sand-shovelling could help "And it seems that what they do extra is to shovel it on top of themselves, and get gravity to help. "So if they want to get the water out of moist sand they have to do something extra," Professor Withers said. Professor Withers said although scientists already knew about this, they weren't sure whether thorny devils could fill their capillary channels and drink just by standing on moist sand. So this lizard has evolved a bizarre alternative to drinking with its mouth: the capillary channels on its skin squeeze every last drop of moisture out of the arid landscape and push it towards the animal's mouth. Thorny devils can't simply lick water from puddles or drops of condensation because their entire mouth - including the jaw and tongue - has evolved specifically to feed on small ants that share their habitat. 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." A mouth so specialised it can only eat ants "I think it might be more important for the extreme circumstances. "Clearly, it's important for them - this special system has evolved and it's really quite bizarre," he said. Philip Withers, a professor of zoology at the University of Western Australia and co-author of the research, said the creatures' remarkable skin is critical to their survival in the harsh conditions of the desert. Scientists have studied the water-wicking properties of thorny devil skin for more than 40 years.Ĭhannels between the animals' scales draw moisture towards their mouths, where they squeeze it inside in miniscule gulps.īut in the devils' habitat - the arid deserts and sandy plains of central and western Australia - what hasn't been clear is exactly where they get the water from.ĭo they rely on rare puddles, or harvest droplets of condensation, or do they suck water from the sand itself?Ī study published today in the Journal of Experimental Biology suggests that one of the main ways thorny devils drink is by burying their bodies in damp sand, and then drawing the moisture out of it.
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