Living with deer: we've moved into their neighborhood. Now guess who's coming to dinner

Animals, Fall, 2002 by Brian Lavendel

Even if regulations are changed to promote more deer hunting, long-standing traditions of limiting hits to prized bucks and of refraining from targeting does are likely to keep hunting from being an effective means of population control.

Now biologists are facing the prospect of a spreading disease in the deer herd, which some observers say may be the result of overcrowding. Chronic wasting disease (CWD) was found last spring in several deer in Wisconsin. It's the first time the disease has appeared east of the Mississippi River. (The disease had been diagnosed in free-ranging deer and elk primarily in northeastern Colorado, southeastern Wyoming, and adjacent Nebraska.) This brain disease-related to bovine spongiform encephalopathy (mad-cow disease)--is likely caused by an abnormal protein called a prion.

"CWD is not a surprise to anyone who works on overabundant deer," says Rooney. "To bring the population down, it's probably going to take some sort of disease that comes from maintaining this [unsustainable] population."

In his botanical research, Rooney has found that the impact of overabundant deer extends throughout the ecosystem. The Wisconsin forest floor has been clear-cut by hungry deer, says Rooney. "There are few shrubs and very few, if any, saplings. Conifer branches are eaten six or seven feet up the tree."

Plants affected by deer overgrazing include trees, such as eastern hemlock and white cedar, and wildflowers, particularly trilliums, orchids, and lilies, reports Rooney. Some may have been all but eliminated from broad areas of their natural habitats. "Species that were very abundant just 50 years ago are becoming increasingly scarce," he says. Changes in the plant community reverberate throughout the forest ecosystem--diminishing food sources and habitat for birds and insects. For instance, the endangered Karner blue butterfly depends on wild lupine, a plant also favored as a food source by deer.

In extreme cases, heavy deer browsing can eliminate forest shrubs. This can spell trouble for many bird species, including the hooded warbler, which requires shrubs for nesting.

As with other species whose populations humans have dramatically influenced--the passenger pigeon, the Canada goose, and the raccoon--whitetail deer have taught us how little we know about managing wildlife. Demands to correct deer "imbalances"--often lethally--continue to generate debate.

In the meantime, animal advocates strive to give people the appreciation and knowledge of wildlife the Bjorgaards enjoy. Besides deer, the family has enjoyed observing wild turkeys, geese, black and white squirrels, and woodpeckers. "When I was a child, I grew up with woods in my backyard," Pat recalls. She wants to offer her children the same up-close exposure to nature. If that means slowing down on the way home of planting a deer-resistant species of shrubbery, so be it. "We try to work with them," she says of her welcome wild neighbors.

Caution: Dear ahead!

The New York State Department of Environmental Conservation and the Metropolitan Washington Council of Governments offer these tips to help motorists reduce their chances of striking a deer.