Deer’s detection system is impressive

By V. Paul Reynolds

As most hunters are aware, Nature has blessed the whitetail deer with a danger detection system that is remarkably keen and effective. Experts differ on which of the big three, smell, hearing or vision, play the most prominent role in helping our November quarry steer clear of predators, humans among them.

If you had to pick one from among the deer’s trifecta of danger-avoidance mechanisms, which would you choose?

Sense of smell? This one usually gets the nod during deer camp debates. Modern whitetail hunters go the distance to keep their human scent in check, using everything from special body soap to scent lock clothing and earth-scent sprays.

A man with a lot of credentials has stepped forward to challenge this conventional wisdom. Dr. Leonard Lee Rue II, who is an American icon when it comes to deer photography and deer behavior, argues, quite convincingly, that a deer’s hearing, not smell, should be at the top of the list.

In his new book “Whitetail Savvy,” which is destined to become a classic comprehensive publication on deer behavior, Rue asserts that a deer’s sense of smell, which is acute, only works some of the time. Wind, temperature and other weather conditions can really compromise a deer’s ability to smell danger.

Rue, whose credentials in this area are rock solid, believes that a deer’s keen hearing is its key defense.

Here is an excerpt from Rue’s book on the deer’s auditory system:

“A deer can be in a deep sleep, but its ears never stop moving, winnowing its surroundings for the slightest sound of danger. What is more remarkable is that even while a deer sleeps, its brain is analyzing and filtering out sounds that don’t represent danger.”

Rue says that a noisy squirrel or a falling limb won’t cause a deer to awaken but a distant human footfall will bring a deer to full alert. A deer, he points out, also can use its large ears like a revolving radar dish. Unlike humans, who turn their heads to hear a distant sound better, a deer can move its ears toward a sound without turning its head.

Additionally, a deer has a hearing frequency range that can go as high as thirty thousand cycles – twice that of humans!

Scientists and wildlife professionals are learning more about a deer’s third important sense, its vision. Although a deer’s eyesight is not as good as ours, 20/60, it more than compensates with other vision attributes. Because, unlike humans, deer have more rods than cones, they see a lot better than you do in low-light conditions, in fact 18 times better than we do. They don’t do so well, however, discerning color. They see hunter orange as gray. And, for some unexplained reason, they do see the color blue 20 times better than humans. (No blue jeans in the woods, folks)

Most interesting of all, deer can spot and process any movement much faster than humans. And, because their eyes are set differently, they have an uncanny field of vision that extends 300 degrees!

All of this may explain a couple of common beliefs that are engraved in the longstanding protocols of Maine deer hunting. Deer hunting is a challenge and, under fair-chase practices, only one in four hunters fill their tags. The most successful deer hunters keep their scents down, sit still as long as patience will allow, and always, always play the wind.

The author is editor of the Northwoods Sporting Journal. He is also a Maine Guide and host of a weekly radio program “Maine Outdoors” heard Sundays at 7 p.m. on The Voice of Maine News-Talk Network. He has authored three books. Online purchase information is available at www.sportingjournal.com.