JANESVILLE — Despite the Wisconsin officials efforts, Chronic Wasting Disease (CWD) seems to be one of the most effective hunters of deer in the state.
During the past 14 years, the Wisconsin Department of Natural Resources (DNR) reported the prevalence of CWD in adult male deer in its western monitoring area has risen from 8 to 10 percent to about 30 percent.
In adult females, the prevalence has risen from about 3 to 4 percent to nearly 15 percent. The western monitoring area includes the western part of Dane county and the eastern part of Iowa county.
Near Janesville, in the DNR’s southeast monitoring area, the infection rate among adult male deer has risen from nearly 3 percent in 2003 to 8 percent in 2015.
Rates for yearling males and adult and yearling females have risen from 1 percent in 2003 to 3 percent in 2015.
Michael Foy, DNR county biologist for Rock and Green counties, said CWD is a neurological disease that can be spread through contact with other deer.
“(The disease) causes basically holes that appear in different parts of the brain, which makes the brain look like Swiss cheese,” said Foy. “More and more, the deer gets debilitated and becomes zombie-like.”
Foy said the infection takes 15 to 24 months to work its way through the deer’s system, causing the deer to slowly lose its fear of people and sense of direction.
Though there is no confirmation of the disease having any effect on humans, since CWD is a neurological disease, the Center for Disease Control and Prevention and the World Health Organization recommend the public do not eat infected deer.
Over the border in Illinois, approximately 1.6 percent of the total number of deer tested were positive for CWD in 2015. That number was 1.4 percent in 2014. In Winnebago county, 166 deer have been discovered with CWD since 2003. Winnebago is the only county in Illinois to even reach 100, besides Boone county at 138.
Doug Dufford, wildlife disease and invasive wildlife program manager for the Illinois DNR, said the first documented case of CWD was in Roscoe, Ill., in 2002, and the disease has spread from there. However, the CWD rates in Roscoe have only increased one or two percent since then.
Dufford said the DNR has created a special CWD hunting season in counties where CWD has been discovered. The DNR also initiated a sharpshooter program where they will attempt to eradicate all of the deer within an approximate two-mile radius where CWD is found.
He said CWD is transferred in family groups. They try to remove all the deer, because even though females are stagnant, they control reproduction. However, males can travel 20 miles and are also twice as likely to be infected with CWD. Therefore, the DNR choses to eradicate every member of the population in the CWD infected zone.
After hunting season ends, from the end of January until March Dufford said the DNR runs a sharpshooting program to also target infected populations.
“We’ve been able maintain infection rates at a low level,” Dufford said. “In an ideal world, you’d be able to eliminate the disease, but we don’t have the tools.”
Back in Wisconsin, the two areas near Madison and Janesville are the areas Julie Widholm, CWD operations biologist for Southern Wisconsin, said the DNR has been watching since the disease was first discovered in 2002 in the Dane/Iowa county area.
“Dane/Iowa county is the worst, and it’s been spreading out from there,” Widholm said.
She said in 2012, CWD was detected in Juno and Adams County. Widholm said there is an outlier in Washburn County.
One solution Wisconsin had to the CWD problem was the creation of the Earn-a-buck program. In order for a hunter to shoot a buck, hunters had to shoot an antlerless deer. Widholm said this was to lower the population that would then help stop the spread of the disease.
“If you want to lower the deer population, you want to go after the females,” Widholm said.
However, Foy said in 2011 legislatures removed the program due to doubts of its effectiveness.
In 2010, the Wisconsin Department of Natural Resources (DNR) released a 25 year long response to CWD. Widholm said the DNR will discuss five year amendments to the plan this summer and will be presenting a proposal by December.
Dufford said he is “somewhat encouraged” that Wisconsin is rethinking past strategies so the state’s disease rates can be lowered.
Dufford said corroboration between Wisconsin and Illinois has been a priority for both states since the infection first began in the Stateline Area.
“Biologist realize that if one of us loses, both of us are going to lose,” Dufford said.