Think of it like the signs that invariably hang in zoos: Don't feed the animals.

It's been a vicious winter for the state's deer herd. It's been cold. It's snowed heavily. Finding food has been difficult. But as bad as Mother Nature has been, a bag of feed off the shelf at the local supply store can be even worse.

That's right. Feeding deer in our backyards can be worse than letting them fend for themselves.

Common sense tells me that domesticating wildlife in any fashion is simply bad business. Now we're armed with the science to back it up.

According to local wildlife biologist Keel Kemper, there are three major factors to consider when it comes to feeding deer -- increasing the odds of a collision with a car in populated areas, making the herd more susceptible to predators by drawing them to a central location and, perhaps most dangerous, inviting disease to spread like wildfire.

When it comes to protecting one of Maine's most precious natural resources, we may well be our own worst enemies.

"Anytime you congregate critters in one place, there are problems," Kemper said. "There are real downsides to feeding deer.

"Look, the reality is that people don't feed deer for the deer. They feed deer for themselves, because they like to see them."

I don't like the idea of deer starving in the middle of winter any more than the next guy. It's nature's brutal way of guarding against overpopulation, and there's nothing tasteful about it.

But I can think of something that's far, far worse -- a perfectly healthy animal dying in less than 24 hours from a violent illness, the kind of illness brought on because we simply toss a bag of deer feed out into our backyard while under the dangerous impression that we're doing "the right thing."

There are two diseases most closely associated with people feeding deer, and they have the complicated and not-easy-to-pronounce names of "acidosis" and "enterotoxemia." In both cases, they result of a significant shift in an individual deer's eating habits.

Acidosis, a grain overload, occurs when deer suddenly start eating a diet rich in carbohydrates -- the very type of thing routinely found in mass-produced deer feed. The switch from a woody, fiber-laden diet to one rich in carbs essentially shocks their systems into malfunction and causes such unpleasantries as dehydration, diarrhea, incoordination and, ultimately, death.

Enterotoxemia, an overeating disease, happens when too much of the starchy food source passes undigested through the system -- creating a breeding ground for micro-organisms. The excessive bacterial growth, according to a Michigan Department of Natural Resources study, releases toxins that attack the deer's central nervous system. Death of an otherwise healthy animal sets in exceedingly quickly.

"We should absolutely discourage it," Kemper said of people feeding deer in their yards. "You just run a really high risk of killing deer."

The greatest danger we as humans impose on deer is reactionary feeding -- through our windows we see the thermometer dip into single digits or we see a snow and ice storm swirling, so as a result we head out, buy a bag of deer feed and leave it out for cold and hungry animals. To feed deer "correctly," albeit at the risk of having them count on us as a viable food source, the feeding needs to begin when the weather is warm.

Feeding the deer slowly allows their delicate digestive systems to absorb food high in carbohydrates.

"It all boils out to bacteria in their stomach," Kemper said. "If you're going to do it, you need to start feeding them long before they need it. They really need three or four weeks to acclimate themselves to it."

Still, Kemper says, we're much better off to just let deer find food for themselves. Getting people to recognize that feeding deer does more harm than good isn't an easy task, and Kemper and other biologists understand that.

"It's a Maine tradition," Kemper said. "For years, people have been feeding deer. People used to cut down cedar boughs and leave them in their yards for deer, even though now we know that cedar is more valuable left as cover in the woods than as a couple of days' worth of food on the ground."

People may think they're helping Maine's deer herd by feeding them as we reach the final stages of a trying winter season, accepting for fact that a full stomach has to be better than an empty one.

Of course, we also once accepted as fact that the earth was flat -- and we're all well aware how wrong that notion turned out to be.

For more about feeding deer, visit: http://www.state.me.us/ifw/wildlife/

species/deer/feeding_deer.htm

Travis Barrett -- 621-5648

tbarrett@centralmaine.com