The Wisconsin Department of Natural Resources released their 2020 wildlife survey results on May 21.
The survey details nuisance bear reports, bird banding, fall turkey numbers and a range of information regarding the state’s deer population. A major focus of the surveys is chronic wasting disease (CWD).
The Wisconsin DNR began monitoring CWD in 1999 as the neurological disease spread across the country. The disease was first detected in the state in 2002. The major area of concern in Wisconsin is the southern third of the state. This area, which cuts an east-west line from the northern edge of Vernon County across to Lake Michigan, makes up the southern farmland deer management zone. Cases in this zone have historical been exponentially higher than in any other part of the state, and this year’s data continued that trend.
Almost 19,000 deer were tested for CWD in Wisconsin over the course of 2020. There were 1,578 CWD positive results. The southern farmland zone made up almost half of the sample size, with over 9,000 deer tested. But, they made up 98 percent of positive cases. Of the 1,578 CWD positive deer tested, 1,549 were from the southern farmland zone.
The total number of positive results increased when compared to 2019, as has been the trend since 2014. Statewide cases hovered between three and six hundred from 2012-2017, before a dramatic increase in 2018. However, the state’s testing efforts also nearly doubled between 2017-18, which is most likely the explanation for the quick jump in positive cases.
Polk County is part of the central farmland deer management zone, which saw the second highest number of deer tested, behind the southern farmland zone, but not nearly the percentage of positive results. Of the 6,636 deer surveyed, 19 tested positive for CWD, a positivity rate of .002 percent. By comparison, the southern farmland zone had a positivity rate of almost 17 percent.