By Esther Lutz, East Central IL Master Naturalist for University of IL Extension in Coles County
Watching the birds in our backyards is a pastime for all seasons. These last couple of weeks have been so hot and muggy, however, that I've noticed a new behavior in the birds that has become quite regular-- especially on those sultry afternoons when the heat is just unbearable: Bird showers!
Oh, you should see them! I stuck a fairly tall and sturdy dead tree snag in the ground next to the bird bath so its horizontal branches reach over the bowl. This gives the birds a perch on which to land and look things over as they decide whether it's okay to hop in and splash around, take a drink, or both! Some are more tentative than others, of course. But it seems like once they decide that everything is safe and secure, down they go! And I get to enjoy the free show!
Watching the birds treat themselves to the cooling effects of fresh water makes me wonder how the rest of nature's creatures are enduring the hot sun and 90+ degree temperatures. Even I can barely stand the blast of hot air when I open the back door and venture out -- and our yard is pretty shady most of the day! Just what are some of the strategies that outdoor creatures use to beat the heat?
Shedding. Since being covered with body fur is a characteristic of mammals in central Illinois, it makes good sense to have a way to lighten the coat for summer wear. The biting winds and frosty temperatures of winter cause their outer coats to become heavy to preserve body warmth. Once spring comes around, hormones in the body cause these dense coats to fall out gradually, sometimes in large patches, until a lighter summer coat is in place. (The enormous amount of cottony tufts of fur resulting from the frequent "raking" of our Great Pyrenees' fluffy white coat is all the proof I need that this is true!)
Radiating heat from the body. Some species, such as rabbits, mice, chipmunks, squirrels, bats, foxes, coyotes, and deer lose heat through their ears which they hold up and out from their bodies. The blood flowing into the ears carries heat with it, and the thin skin on the inside of the ears enables the heat to dissipate out at a fairly rapid rate. The cooled blood then flows back into the body's bloodstream and helps to reduce the heat's adverse effects on other body systems.
Panting. We have all seen dogs and even cats pant when they are stressed from high temperatures, and breathing rapidly (panting) helps the body rid itself of excess heat. If we think back to the cold days of winter, we know that when we breathe out into the cold we can see our breath in small clouds because it is hot in the frigid air. Many species of animals get rid of excess body heat by panting. Perhaps you have even noticed birds in the summer walking around or perching with their beaks open -- they are panting when they do this. The air sacs in their high-functioning respiratory systems help the lungs, through panting, to rid their bodies of excess heat in much the same way as in other animals.
Hiding. Just as we do, many animals seek out shelter during the heat of the day. Since cold-blooded species are unable to regulate their own body temperatures, they must depend on the air temperature around them to provide the warmth their bodies need. But when the hot summer sun beats down intensely, these species are very susceptible to physiological damage from so much heat. Reptiles (especially snakes and lizards) are sensitive to this and in fact can die after only a few hours' exposure to the summer sun. Their task on sweltering days is to hide out under rocks or fallen logs, or in underground burrows until the environment cools. Land tortoises (also reptiles) will burrow under moist forest litter and fallen branches and logs to remain comfortable until a fresh summer rain cools things off. Amphibians such as toads and salamanders will burrow under leaf litter and stay in shady protected areas until they feel comfortable enough to venture out again. Frogs will burrow into the mud or linger in the coolness of the water, while aquatic turtles and freshwater fish go into cooler, deeper water during heat waves. Entire populations of these animals can be affected if the heat goes on too long, as they are unable to feed and breed adequately if so much time is spent hiding from the sun. And one of the best ways to cool down for mammals (in their furry coats) is to seek out shade and remain inactive when heat waves bear down upon them.
Aestivation. To avoid heat and drying, some species will enter into a state of dormancy called aestivation during hot periods. Various species of toads, frogs, snails, and even some types of ground squirrels engage in this protective behavior. This is a time of deep "sleep" or summer torpor during which they burrow underground and remain there for a time, lying quietly in their retreats, using stored food reserves in their bodies until the rains come and temperatures cool off again. (Animals in desert climates especially use this behavior to sustain themselves during unfavorable hot periods.)
Sweating. Some animals have the ability to sweat just as people do, the horse being a perfect example. Sweating wets the skin, and the evaporation of that moisture helps to cool the body, making the animal more comfortable and helping it to regulate its body temperature. Species in the canine and feline families have some sweat glands in the bottoms of their feet, but that is a minor help at best as it is not a large enough surface area to cool the entire body completely. So what do these animals do? They employ other methods for cooling such as panting and shade-seeking, and drinking plenty of water.
Water. There are many species of wildlife that benefit greatly from taking a dip to cool off. If you provide water for backyard wildlife, then it is most likely a welcome oasis for these creatures in hot weather. Toads, frogs, salamanders, and turtles will often benefit from simple water receptacles set at ground level, and birds in particular enjoy taking baths in a simple bird bath set up in the yard. Not only does it help them to cool off, but water helps to hydrate the skin of amphibians. It cleans the birds' feathers so that they remain in peak condition for flying and for insulation from the heat. And of course, we must not overlook the importance of water for drinking, as animals of all types must keep themselves hydrated so that their body systems continue to run efficiently.
While summertime is a wonderful season to be outside and enjoy the beauty of the natural world, it has its challenges for nature's creatures, there's no doubt about it. Excessive heat is never pleasant to endure; our human bodies are just not equipped to handle it for long periods without relief. But the wildlife around us cannot resort to air conditioning and chlorinated pools to refresh their bodies and remain comfortable in hot times. Nature has equipped them not only with various behaviors to alleviate their hardships, but also with incredible abilities within themselves to rid their bodies of discomfort and to safeguard their very lives. Indeed, survival of their species depends on it.
The little birdbath in our backyard remains a popular place. It's comical to see the individual birds line themselves up on that overhanging branch and actually take turns hopping down and splashing in the water. They're so courteous! I saw five different species at one time one day, each bird just waiting politely until the coast was clear so it could jump down into the sparkling coolness and splash away. And besides that, they don't seem to mind the free showers flung on them as they wait! They are such a hoot! My poor husband is getting tired of my calling him to the kitchen window yet again to observe another splashing spectacle of feathers, but we get such a kick out of them! Happily, we will continue to enjoy this summertime version of endearing bird behaviors. Looking upon that each day, it can't help but bring
to mind one question: Is it possible for birds to have fun?