CWD: A disease that requires decisive management action on deer herd

Whether deer hunters are ready or not, a new reality awaits: the inevitability, for the foreseeable future, of chronic wasting disease (CWD) infecting Minnesota whitetails, and the manpower, money and sacrifice that will be required to minimize its effect on state deer.

The simple truth: CWD is here to stay. And the only chance Minnesota has to avoid a whitetail infection rate similar to that found in southern Wisconsin — where in some regions about half of adult bucks carry CWD — is to hit the disease hard when it pops up, and keep hitting it, indefinitely.

This likely will mean fewer — perhaps significantly fewer — whitetails in areas where CWD infects wild deer. It's an eventuality that will be especially challenging for hunters in the southeast to accept, because they alone in the state have been governed in recent years by antler point restrictions (APRs), which have boosted the number of adult bucks in the region's herd and made the southeast a trophy-deer hot spot.

The question now: Will the Department of Natural Resources be given the support by hunters and the money it needs by the Legislature to minimize the effect of CWD on Minnesota deer?

Or will innuendo, rumor and armchair quarterbacking stifle the agency from doing what needs to be done to keep CWD in check?

At stake is deer hunting as we know it.

Stepping up the hunt?

Minnesota's five-year hiatus from CWD in wild deer ended in November, when two bucks killed by hunters within 5 miles of one another near Lanesboro were found to be afflicted with the always fatal disease. Before that, only one Minnesota wild deer had been confirmed CWD-positive, an animal shot near Pine Island, also in the southeast, in 2010.

Last month, the DNR established a 371-square-mile disease management zone surrounding the area where the two infected deer were killed. A special 16-day public hunt held there ended a week ago, followed by a landowner hunt that is ongoing.

The hunts produced four more deer that tested positive for CWD, raising the total to six. Three were killed by hunters within about a 5-mile circle of the original two, and another was felled about 10 miles north of that cluster.

The hunts' intent was to kill 900 adult deer, and from that sample infer the region's relative CWD prevalence. But with the number of infected deer now totaling six, DNR wildlife disease specialists are contemplating killing still more animals to determine the extent of the disease.

To accomplish the larger harvest, sharpshooters might be deployed in coming weeks in the area where the five infected deer were found. Their job, essentially, would be to kill as many deer as possible for testing, and to reduce — perhaps significantly — the number of animals in the core infected area.

A question of interests

Some hunters in the southeast and elsewhere believe the DNR is misguided in its CWD response and/or that its motives are disingenuous in wanting to kill so many deer in the region.

Some have speculated that auto insurance companies are behind the plot and have convinced the DNR to take this opportunity to kill whitetails to reduce car-deer collisions.

Others believe the DNR is caving to landowners who want fewer deer in the southeast, or that, for whatever reason, the DNR itself wants fewer deer in the area, and is using CWD as an excuse to accomplish its goal.

Such criticism likely will intensify if sharpshooters begin their work, which would continue until spring green-up. Killing so many deer, they will say, is a waste of time, money and otherwise good animals, because CWD is inevitable.

Paul Shelton has heard it all before. He's the Illinois DNR's top gun on CWD.

"Deer hunting is hugely popular,'' Shelton said. "And you'll always have a subset who will say, 'Why are you worried about CWD, since there is no risk to humans?' Well, it's difficult for us, too, as wildlife biologists to make decisions to reduce a herd where we find CWD. It's distasteful. But we think it's best for the herd.''

Shelton's tack to limit CWD is similar to the one Minnesota wildlife specialists plan: Test widely for the disease among deer killed by hunters; determine where new disease hot spots exist, and attack those areas aggressively with liberal hunting seasons and, as necessary, sharpshooters.

"On average our sharpshooters will kill about 1,000 deer in specific CWD areas that are perhaps 100 sections or less,'' Shelton said.

Illinois' CWD fight is particularly challenging because it shares a border with southern Wisconsin, where CWD is widespread and where wildlife managers have essentially given up controlling the disease.

Wisconsin's top CWD expert, Tami Ryan, said her state lost the CWD battle because by the time it was discovered there in 2002, the disease likely was well-established. "Modeling done by university researchers,'' she said, indicate "an approximately early 1990s introduction'' of the disease in Wisconsin deer.

In Illinois, Shelton said, CWD "isn't going away.'' But the state's aggressive approach in removing deer faster than the disease can spread seems to be working.

"From 2002 to 2007, the CWD prevalence in southern Wisconsin was about the same as ours, less than 2 percent,'' Shelton said. "But beginning in 2007, their rate took a rapid rise upward, while ours has stayed about the same, about 1 percent or so.

"Our hope is by keeping the prevalence as low as we can, we can keep CWD from spreading into the rest of the state while researchers try to figure out a vaccine or other tools for us to use against the disease in the future.''