We all understand the necessity of having roofs and raincoats to keep out water during wet weather, but how many of us understand that land animals need waterproofing to keep water IN? Among the great natural inventions is one that does just that—the waterproof skin!
Consider the frog, who lacks one. In our desert climate, it only takes a few hot hours to turn a stranded frog into a very dead, mummified corpse. On the other hand, reptiles—and their relatives, the birds—do very nicely encased in skin that allows little leakage of the precious water within.
What about our own group, the mammals? They too have waterproofing, but
some take it more seriously than others. Those active during the cool hours conserve
water with the best of them. We who are active during the heat of the day, though,
bypass the water barrier, secreting moisture onto the skin's surface for the
cooling benefit of evaporation. Wasteful? Perhaps, but avoiding death by heat stroke
takes precedence over the loss of replenishable water any day.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.