It’s Hot Outside: How Animals Cope With the Heat


How hot is it?

It was so hot last week I saw a dog chasing a cat and they were both walking.

Okay, so Vaudeville, like that joke, is dead. But how animals cope with hot weather is no joke. If they don’t stay cool, they die.

Amphibians, like boreal chorus frogs and tiger salamanders (both common east of the Continental Divide), need to keep their skin moist and cool. That can be hard to do during summer on the hot, dry prairie of central and eastern Montana.

Boreal frogs are heard everywhere in the spring and early summer. During their April-June breeding season their loud, short chirp that resembles the slow running of fingers over the teeth of a comb, seems to come from every prairie pond and water-filled roadside ditch.

Tiger Salamander

An odd looking creature, the tiger salamander is an amphibian, native to central and eastern Montana.| Photo courtesy of Wikipedia

Then arrives July’s heat and the small frogs that measure only about an inch long disappear. Actually, they will go underground, beneath vegetation, into water tanks, or even on building foundations. Whatever it takes.

Tiger salamanders survive by spending daylight hours in borrows, under logs and rocks or in prairie dog burrows. People sometimes find this secretive six- to eight-inch-long amphibian in basements, window wells or stock tanks.

The tiger salamander’s coloration makes it appear odd to most; its body typically a crazy quilt of blotched olive or pale yellow markings on a black or dark green background.

But the fun really starts the morning after a summer downpour when folks not used to this psychedelic looking critter find it on their patio and wonder what the gates of Hades hath spawned.

For mammals, one method of dealing with heat is changing their winter coat to a summer one.

In May and June, white-tailed deer shed their thick winter hair, replaced with thinner reddish-brown hair.

By the early fall, their winter hair grows through the summer coat to create a gray or grayish-brown coat.

Elk are similar. Right now they are wearing their summer hair, a deep reddish-brown color with little or no under coat, giving them a sleek look. By early September, they are changing into their darker, thicker winter coat.

And then there’s night time. Many animals (bears, raccoons, and deer) lay low on hot summer days and become active at night. Many of us did the same as teenagers.


Nighthawk | Photo by Dave Irving

Birds, except for owls, are mostly active by day. When it gets too hot some birds get rid of extra body heat through their respiratory (breathing) system, which collects warm, moist air from overheated internal tissues and expels it through its lungs. Basically they pant.

A peculiar method used by the common nighthawk (it’s a bird but not a hawk) is to go into a deep, deep sleep, called torpor, almost like a summer hibernation. The nighthawk, a relative of the whip-poor-will of the South, relies on its camouflage to avoid predators as it slumbers away in the heat of the day.

Then there are fish. Lucky the fish that gets to lay in cool water on a hot summer day. Of course they don’t have a choice.

Trout often drop into deeper water because it’s cooler and contains more oxygen than warm water. Ideal trout water temperatures are in the mid-50’s. Once the aquatic thermometer hits 70, they are headed for trouble unless there is cooler, well-oxygenated water they can retreat to.

Stay cool.