Photo by Michael Mauro

Like an ominous sign drifting across the sky, the dark clouds started building the night before opening day. It would have been nice to be able to sit in camp until more favorable weather arrived, but with a three-day window for hunting mule deer, my older brother, Phil, and I didn't have that luxury. By the time the sun should have been casting its warming glow on the world opening morning, steady streams of water were running off the brims of our hats. It wasn't the most comfortable mule deer hunt I have ever been on, but it ranks right up there as one of the most educational.

Every hunter has learned the importance of knowing the behavior of their quarry. But we tend to fall into a trap of learning only the behaviors that are pertinent to us -- what bucks do during the rut, how they will react to a spooked doe, how far away they're likely to bed from feeding areas. For 90 percent of hunting situations, this knowledge is invaluable.

But when conditions change, deer behavior changes with them, and the best way to adapt is by understanding what the deer do, and why they do it.

As I sat in the torrential downpour that morning, there was a voice inside my head screaming out that no reward was worth this misery. Sitting under a tree in Gore-Tex raingear and boots lined with Thinsulate, I wondered how I would cope with this if I lived in the mountains without the comforts of protection that modern technology provided. The answer, as obvious as it sounds now, is that I would find a warm, dry place to hunker down. Which is exactly what the deer do.

"As far as thermoregulation, heavy rain is much more difficult for deer to deal with than snow," said Woody Myers, a deer biologist with the Washington Department of Fish and Wildlife. "Their coats are a little oily, so there is a little rain protection, but only to a point. So, that's a good reason for them to get out of heavy rain."

A deer's first priority is cover. Obviously, thick forests with multiple layers of canopy that have the greatest chance of absorbing the majority of the rain before it hits the ground would be ideal for deer. But in a great part of mule deer country, such forests do not exist. In these cases, the deer will take whatever they can get, even if it means hunkering under a thick sagebrush clump.

Because mule deer have adapted to hot, dry habitats, their bodies have developed efficient ways to regulate temperature by giving off excess body heat. Mule deer channel heat into their large ears and long legs, which allows the wind to quickly cool them.

"Their ears and legs help in getting rid of heat," Myers said. "But the converse is also true."

As important as it is for them to get out of the rain, it's critical to escape the wind. Box canyons, gullies and other natural contours of the land that give deer protection from wind are logical places for them to hole up and wait out a storm. Keep in mind, however, that their major natural predator, cougars, attack from above, so areas that could be likely ambush spots aren't apt to have deer bedded down -- unless they have no choice.

"It really depends on the intensity of the rain," Myers said. "A mild shower really isn't going to affect them, but in heavy rain they'll tend to seek cover and gain some thermal advantage by staying out of the wind."