Copyright 2001 eNature.com
September 07, 2001

Thanks to the Disney classic Bambi, many Americans carry a distinct image with them of the way animals react to wildfires: thousands of terrified creatures dashing madly for a river as a wall of flames approaches. However, this image is hardly accurate.

The truth is that while some animals die — more often as a result of suffocation than immolation — most wild creatures possess survival skills that help them avoid dying in fires.

Birds have the most obvious advantage: the ability to fly to safe locations when flames appear. The fact that most fires strike during late summer or fall, after breeding season, means that few species of birds still have flightless young or nests to protect. Last year's Los Alamos fire was an exception. Because it occurred in mid-May, many nests with eggs or young birds were lost.

Large mammals can usually stay ahead of fires by walking. Even huge blazes seldom move faster than two miles per hour, so these animals can safely flee the advancing flames. Also, most fires don't burn evenly across a landscape, and animals can seek refuge in the areas of unburned terrain.

In the 1988 fire that swept across Yellowstone National Park, the confirmed count of large mammals killed, according to one report, was 5 bison, 1 black bear, 2 moose, 4 deer, and 245 elk — a surprisingly low body count when you consider that the fire consumed almost 1.5 million acres.

Small animals, by contrast, most often seek refuge below ground in burrows or other cavities. Even flightless insects dig their way into the upper soil or humus as the flames pass. The fire may be burning out of control, but the temperature just a few inches below the surface remains unchanged.

One small mammal that doesn't fare well is the wood rat. In forested areas these rodents live in nests made of sticks and other dry vegetation placed just above ground level or low in trees, and these sites are extremely vulnerable to understory fires.

Sadly, some of the worst damage associated with fires is caused by human efforts aimed at fire control. Firebreaks created by bulldozers result in more long-term habitat degradation and associated impact on wildlife than the fires themselves. Likewise, fire retardant dropped by aircraft can poison fish and other aquatic creatures.

To make matters worse, the presence of low-flying helicopters, droning bulldozers, and fire crews often confound the efforts of animals trying to escape. In fact, one report on the Yellowstone fire states that about a hundred of the large mammals listed as killed during the fire died as a result of collisions with fire-fighting vehicles.

Plants and animals are more resilient and resourceful than most people think. Not only do many creatures survive wildfires, some even thrive in the wake of conflagrations.

The Toxic Trade-off

Being poisonous has its advantages. It certainly deters predators. And it reduces stress. A poisonous rabbit, rather than sprinting to its destination, could saunter at the speed of a rough-skinned newt, the most poisonous salamander on the planet.

One rough-skinned newt on the West Coast contained enough poison to kill 25,000 mice. Needless to say, mice are not one of its predators. Only one animal preys on this newt: the common garter snake. Whereas another snake will die if it eats a rough-skinned newt — often before the newt dies — the garter snake merely loses muscle control for a few hours.

The downside, of course, is that a snake who can't move has no control over its body temperature and could potentially overheat. Likewise, the snake can't hide if a coyote approaches. And eating rough-skinned newts makes the snake slower even between meals. Scientists have found that the greater a garter snake's resistance to the poison in the newt — and resistance varies from place to place — the slower it moves, which affords the newt a better chance to escape. Error: Unable to read footer file.