Driving through the Discovery Place parking deck one morning, I noticed a van had just hit a moth. Interested in identifying what type of moth had just suffered this unfortunate fate, I quickly parked and headed toward the scene of the “hit and run” with the intention of collecting the critter and getting it to my office. But as I approached, an uninvited guest swooped down and stole the object of my wonder, carrying it just out of my reach. As the thief started to peck vigorously at his prey my insect friend bounced in small arcs over and over in a brave attempt to escape. The attacker was not giving up easily though, doggedly pursuing the moth as I, wide eyed with wonder, marveled at the ancient predator vs. prey drama unfolding right before my eyes.
Finally, as the moth surrendered and his predator, now identified as a House Sparrow , (Passer domesticus), flew away with a full stomach, something occurred to me… the sparrow had just burned an excessive amount of energy capturing and consuming the moth on a very hot day. How could this bird possibly stay cool as it fought with so much gusto to overcome a feisty insect? It didn’t even appear to break a sweat!
Curiosity got the best of me, so I did some research and learned that only mammals - a group to which I am proud to belong - can have sweat glands…although, not all mammals do. Whales and cats do not. This leaves them to find alternative ways to cool down. And find them, they do! Cats, for instance, pant to release heat with their breath or lick themselves to cool down (glad I am not a cat) .
What about birds? I know their body temperature is warmer than a human’s, and therefore it doesn’t take as much to cool them down. I also know they, too, have discovered unique ways to fight off the heat. For example, vultures use UROHYDROLYSIS - a process where they urinate on themselves to cool down (glad I’m not a vulture, either). Urine contains uric acid which is an antiseptic – a substance that prevents the growth of microorganisms - so the process works double-time for vultures, since the rotting carcasses that they call dinner can contain disease causing organisms.
As it turns out, I didn’t get a chance to identify the moth - but in an attempt to do so I traveled down an entirely new path of wonder. Is science fun or what?
So I ask you out there: How in the world do birds and other animals lacking sweat glands cool down? How could you find out?
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Vice President, Learning Experiences 7 Posts
Robert Corbin is VP, Learning Experiences at Discovery Place. Prior to joining Discovery Place in 2007, Robert spent 15 years in the Charlotte-Mecklenburg school system, teaching science and serving Science Academic Content Coach and mentor. Robert has developed science curricula for the Weather Channel, Paramount Pictures, the ASPCA, and the Environmental Literacy Council and he wrote curriculum to accompany Al Gore’s film, An Inconvenient Truth.
Robert holds an M.A. degree in Natural Science Teaching from the University of South Carolina and a B.S. in Science Education from Michigan State University and recently completed his doctoral degree at UNC-Charlotte.
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Post a CommentWhile on a family road trip, I asked my daughters (10 and 11 years old) if they could think of ways birds or other animals without sweat glands could cool down. They both agreed that these animals must have unique cooling systems that work within their environment. For birds we came up with these conclusions, (1) they don't fly when it's hot, (2) they fluff their feathers to catch a breeze, (3) when they do fly, they try to converse energy and not get overheated, and (4) they will cool off by splashing in a pool of water. We also thought of the obvious way of panting. Panting made us think of our dog. We decided that she must have sweat glands so we looked it up on the computer and sure enough, dogs do have some sweat glands. Now, for an interesting connecting from the girls. As humans, when we are cold, we try to use our body heat to stay warm. We wear a hat, gloves, sweaters, long pants, and shoes and socks to capture and use that heat. When we get warm, we don?t want to keep or trap our body heat close to our skin. Could birds and dogs do the same thing? Birds will stretch out their wings to dry and cool off. Dogs will lay with their legs spread apart. Do they do this to dissipate heat from their groin and underarm areas? It was an interesting conversation and we agreed that only the animals that can adapt to their environment survive. Thus, whatever they are doing must be working!
Helen Dendinger - August 22, 2010