Surviving the heat
Hot enough for you? Thank goodness we can beat the heat with central air or cold drinks or sitting in the basement.
Now imagine wearing a fur coat or down jacket and trying to stay cool with nary an air conditioner in sight. That’s what mammals and birds have to deal with this time of year.
One method for some mammals is changing their winter coat for a summer one. Take white-tailed deer, for example. In May and June, whitetails shed their thick winter hair, replaced by thinner reddish-brown hair. Come September and October, their winter hair comes in growing through the summer coat to create a gray or grayish-brown coat.
Elk are similar. Now they’re wearing their summer hair, a deep reddish-brown color with little or no undercoat, giving them a sleek look. Yet by archery season in early September, elk are changing into their darker, thicker winter coat.
Changing a winter coat to a summer version is only one part of staying cool. Moose will move to higher elevations, seeking the coolness that brings. If they can find it, elk will rest in the shade of a densely timbered north-facing slope, although on some hot days they may be found on high open points taking advantage of any breeze, especially if biting flies are tormenting them.
And then there’s night time. Many animals (bears, raccoons and deer) will lay low on hot summer days and become active at night. Kind of like teenagers, come to think of it.
Birds, with the exception of owls, don’t have the luxury of waiting until dark when temperatures drop. And they need their feathers for flight. They do not have a thinner, cooler summer version.
In warm weather, a bird gets rid of extra body heat through its respiratory (breathing) system, which collects warm, moist air from its internal overheated tissues and expels it through its lungs, according to the Audubon Society Encyclopedia of North American Birds.
We use all sorts of deodorants and lotions to either stop us from sweating or mask the odor, alleged to be a detriment to society by the advertising departments of corporate America. But perspiring, the wetting of our skin by our sweat glands, is how we evolved to cool off.
Birds don’t have sweat glands, so fresh air rushing through a bird’s respiratory system reduces its body heat by picking up and expelling heat radiated from cells and heated blood. Basically, birds pant. Birds will also seek shade, even sitting on a wire in the shadow of a fence post.
Some of our winged friends pulse their throat skin in and out to help cool their bodies, including Montana birds like great blue herons, cormorants, pigeons and pelicans. It’s called evaporative cooling.
Another method used by cormorants (a fish eating black-colored bird found along the Missouri River in central Montana) is to perch with wings spread for lowering their body temperature.
No matter how mammals and birds stay cool, nature will eventually usher in fall and lower temperatures, letting them go about the business of preparing for winter. For us, that will mean turning off the air conditioner and turning on the furnace. What a life.
Bruce Auchly is the Montana Fish, Wildlife and Parks Region 4 information officer