School is out, and temperatures are on the rise. It’s official: Summer has arrived. Staying cool is on everyone’s mind, but unlike people, most animals aren’t able to seek the comfort of air conditioning or even able to sweat!
Here in the Bluegrass region of Kentucky, horses, like humans, usually work up a good sweat in the summer sun. Sweating removes heat from the body as water evaporates from the skin’s surface. Other animals also use this method, called evaporative cooling, but in slightly grosser ways. Kangaroos spit on their arms to regulate their body temperature during the intense Australian summers, while storks and vultures poop on their own legs. Covering themselves with saliva and semi-solid waste carries heat away from the animals’ bodies as the water evaporates in a similar way as sweating.
Other animals don’t sweat, but find unique ways to cool off as temperatures rise.
They aren’t called the dog days of summer for nothing. Our canine companions pant, which moves large volumes of air in and out of their lungs to remove heat and stay cool.
Dogs aren’t the only ones who use air movements to stay cool. Some birds, such as owls and mourning doves, prevent overheating with gular (throat) fluttering. When birds do this—think of it as “bird panting”—they move air with their neck muscles and release heat from their bodies.
African elephants use their large ears to dissipate heat. By increasing blood flow to these massive appendages, heat radiates away from their bodies to help the pachyderms stay cool in oppressive temperatures.
African lungfish stay cool using a process called estivation, a form of reverse hibernation, when the heat becomes overwhelming. By burying themselves in the mud and sleeping, lungfish avoid the rising temperatures and stay moist. They pass the summer this way until the rainy season arrives and they awaken to lakes full of cool water.
Pigs have keeping their cool down to a science—the science of sunscreen. To beat the heat and protect their delicate skin from the sun’s harmful rays, pigs roll in the mud. The cool mud pools heat away from the pigs’ skin, leaving them refreshed and coated in a protective layer of sun-repelling mud-screen.
With temperatures on the rise, animals may not have the luxury of climate control, but they have definitely developed savvy ways to beat the heat.
Jessica C. Taylor, PhD, is a cardiovascular physiologist who manages projects for a contract biomedical research organization and teaches undergraduate biology at Centre College in Kentucky.