Environmental Almanac | Supplemental feeding of deer a bad idea

Environmental Almanac | Supplemental feeding of deer a bad idea

If you struggle with the perception that, as a state, we too seldom get things right in Illinois, let me call your attention to the success we've had in managing a life-and-death wildlife issue that's causing far more trouble in neighboring states, Chronic Wasting Disease (CWD).

CWD affects members of the deer, elk and moose families. It was first identified among wild animals in Colorado in 1981 and has spread widely across North America since then. CWD was first detected in Illinois in 2002.

CWD is fatal to all animals that become infected with it. It is caused by a prion, which is an abnormal form of protein — smaller than most viruses — that attacks the nerve and lymph systems. You may be familiar with this as the same type of agent that causes scrapie among sheep and mad cow disease among cattle, and symptoms of CWD are similar to these diseases. These symptoms include weight loss and a long list of gruesome, sad-to-observe behavioral changes (that I'll refrain from describing here) leading to slow but imminent death.

CWD is transmitted directly between deer through contact with bodily fluids, as well as indirectly through prions that are shed by infected animals and then picked up by others from the environment. Currently, there is no evidence that humans are at risk of contracting CWD even when exposed to it. But, as you might imagine given the way it affects deer, nobody's going to say don't worry about it.

In light of what was already understood about CWD, officials with the Illinois Department of Natural Resources (IDNR) and scientists from the University of Illinois, with their long history of collaboration, were well poised to develop and implement a strategy for keeping the disease in check in the very early days of the outbreak.

That strategy, which remains in place today, combines liberalized hunting regulations (i.e., high quotas, reduced-price permits and extra hunting days) with significant culling of affected herds by sharpshooters when hot spots of infected deer are found. Deer killed as part of this strategy that are found to be infected with CWD are retained for study by scientists, while the rest are kept as food by hunters themselves or donated to local food pantries when they test negative for the disease.

Officials measure the success of this strategy according to the prevalence of CWD among deer tested for it, which has remained between about 1 percent and 2 percent in Illinois since it arrived. That's phenomenally low and a great boon for people who enjoy watching deer and for people who enjoy hunting deer (I belong to both groups), as well as deer themselves and the natural communities of which they are an important part. For comparison, the prevalence of CWD among tested deer in Wisconsin, where management efforts were suspended in 2006, has now risen to approximately 30 percent.

I'd like to be able to end this column right here, as a feel-good story, but unfortunately, I can't. That's because the Illinois Legislature is currently considering a bill (SB2493) that would undermine IDNR's success managing CWD by creating conditions that would promote the transmission of diseases among wild deer.

SB2493 would amend the state Wildlife Code to provide "that a person may supplementally feed deer with items otherwise prohibited by the Code when not in active deer hunting season."

Dr. Paul Shelton, wildlife program section head, has already addressed the Legislature to articulate IDNR's opposition to the bill, which is based on a long list of well-understood problems associated with supplemental feeding.

And his agency's opposition is further supported by experts from the UI, experts who helped shape the state's successful management strategy and who continue to monitor its effectiveness, especially Dr. Nohra Mateus-Pinilla, who is a veterinary epidemiologist and director of the Veterinary Epidemiology Laboratory at the Illinois Natural History Survey, and Dr. Jan Novakofski, associate vice chancellor for research compliance and a professor in the Division of Nutritional Sciences in the College of ACES. Their research group was working on CWD before the first case in the state in 2002, and, since then, they have published more than 25 peer-reviewed scientific papers concerning the disease, deer biology and principles of nutrition growth and development in animals.

When I sat down with them recently to discuss SB2493, Novakofski emphasized that, for starters, there's no evidence of need for supplemental feeding of deer in Illinois, pointing out that every year 85 percent of white-tail does become pregnant — most of them with twins — and that 20 percent of fawns are healthy enough to become pregnant before they're even a year old. Beyond that, he added, there's no proof supplemental feed improves health, growth or reproduction in wild deer, which you can tell because manufacturers make no such claims on package labeling, where prior evidence is required.

More importantly, both Novakofski and Mateus-Pinilla hope legislators will understand the potential for supplemental feeding stations to serve as hotspots for the transmission of disease. Glancing at our individual cups on the table as she spoke, Mateus-Pinilla offered the following analogy. "Imagine coming together with a large group of people from a wide area for a meeting," she said, "but instead of people having their own coffees, everyone just drank from one big bowl."

What happens when you do this? Illinois doesn't have to run its own experiment by allowing the supplemental feeding of free-ranging deer to find out; Wisconsin has already done it before us. The results there are high rates of CWD infection among deer, and low rates of satisfaction among people who value wildlife. That's a lose-lose proposition.

Rob Kanter is a clinical associate professor with the UI School of Earth, Society and Environment. You can reach him via email at rkanter@illinois.edu. Kanter shot the accompanying photo in Vermilion County.

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