Deer feeding trend may pose environmental, health risks

Increased winter feeding of deer in Wisconsin and other states may pose significant risks to the environment and to animal and human health, according to a university biologist.

While feeding deer during harsh winter months may seem like an act of kindness, it upsets natural population control by mitigating the effects of a difficult winter on the deer herd, says Don Waller, a professor of botany.

For nearly a decade, Waller has documented the effects of Wisconsin’s booming deer herd on tree regeneration, plant diversity and natural communities overall. He has found that overbrowsing by deer has all but eliminated some plant and tree species once common to the state’s northern regions.

Waller says the accelerating trend of deer feeding, whether at backyard feeders or deep-woods stations and winter deer yards, not only exacerbates the growing environmental problems associated with deer overabundance, but it poses health risks to humans and animals as new diseases emerge in U.S. deer and elk herds.

“You can go to just about any gas station in northern Wisconsin and buy bags of potatoes and corn” for deer feeding, Waller says. “Some people buy tons of feed every year. It has become an industry.

“The problem is that it is short-sighted,” he says. “These acts of kindness can translate into more deer and greater impacts on the state’s ecosystems, and ultimately could contribute to more deer starvation.”

A new concern, Waller says, is emerging disease such as chronic wasting disease, a disease similar to mad cow disease, that has been documented in some elk and deer herds in the western United States. Moreover, bovine tuberculosis has been found in free-ranging deer in Michigan and has been shown to be transmissible through infected feed.

The culture of deer feeding, according to Waller, is multidimensional and quite difficult to quantify. But several trends are evident:

• Baiting by hunters, especially in the north, is a growing phenomenon. DNR warden pilots, perhaps with some exaggeration, reported that the north “glowed yellow” with shelled corn prior to the start of the 1999 gun deer hunt.
• Backyard feeding, often an extension of bird feeding, is on the rise and an industry based on products and feed is emerging.
• Sympathy feeding, where large stocks of feed are made available to deer that congregate in “deer yards” during difficult winters, is on the rise.
• Feeding to attract large numbers of deer to a particular area, the so-called wildlife privatization effect, is a growing trend.

In Wisconsin, there are no limits on feeding deer, but a Department of Natural Resources committee on baiting and feeding is considering the issue and proposals to limit the activity. Minnesota banned deer feeding in 1991, and Michigan, in light of human and animal health concerns, has limited the activity in some areas.

The problem of an overabundance of deer in Wisconsin, says Waller, is coming to a head as a number of factors — a series of mild winters in the 1990s, a declining population of hunters, an intensely managed landscape, the absence of animal predators — contribute to the population boom.

Wisconsin’s deer herd has an estimated 1.5 million animals, a number far higher than the number of deer that lived in the state when European settlers first arrived. Beyond natural controls such as difficult winters, the size of the herd in Wisconsin is most affected by hunting.

“There’s no doubt feeding activity is increasing,” Waller says. “We like to think we’re doing something good for the animals, but we have to concern ourselves with whether or not feeding deer is contributing to other, larger problems.”