Summer is coming. We here in Water4Use have noticed that most countries near the equator are now experiencing droughts. Higher overall temperatures compared to past years has dried up our resources, causing water shortages on populated areas. Allan Lear, CEO of Water4Use, are facinated by these animals who evolved in order to live in harsh environments without water. This article is featured in the March edition of PopSci.
In the driest places on the planet, hydration is hard to come by and easy to lose. Every moist breath exhaled, every bead of sweat that drips off, and every emptied bladderful of urine means wasted wetness and a greater risk of death by dehydration. Yet some animals manage to survive in these places. They get by on almost no water at all, thanks to adaptations that make them super savers and hydration scavengers.
The kangaroo rat never has to drink water - it just gets it from the seeds it eats. To survive in the dry climes of the American West, its kidneys generate super-concentrated urine, and it doesn't pant of sweat. Some species can even lower their metabolic rates so they lose less moisture through breathing.
Camels don't actually store water in their humps, so they have to conserve it. At night, after the chilly Saharan air cools the camel's nasal cavity, mist in its breath condenses inside its nose, where it gets reabsorbed. The camel's extra-twisty nasal passages save up to 60 percent of the moisture it would have lost during exhalation.
During hot, dry periods, this Australian frog secretes a waterproof mucus cocoon that prevents moisture from escaping its body. Meanwhile, the frog hibernates underground, waiting for another rainy season. It can survive for two years or more on the liquid stored in its bladder.
The spikes of Central Australia's thorny devil do more than ward off predators. The lizard's absorbent skin and spines suck up dew from cool night air, rain, puddles, and any other moisture it can get its dry little claws on. Thin grooves in its skin help trap the water, then route it to the lizard's mouth for a tipple.
In the Mojave and Sonoran deserts, several tortoise species survive off their urine. During times of plenty, their bladders swell to hold around 470 ml of aqua vitae - uh, literal aqua vitae, not the powerful medieval liquor. The tortoise can later reabsorb water from its urine to endure a year or longer without a drink.
Sand gazelles in the sweltering Arabian Desert have evolved the strange ability to shrink their oxygen-demanding organs when dry spells hit. Downsizing their hearts and livers by 20 and 45 percent, respectively, allows them to breathe less. Taking fewer breaths means less water lost to respiratory evaporation.
Written by Peter Hess on Popular Science, March 2017