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  • Writer's picturePatrick Durkin

CWD Threatens to Wipe Out a Wyoming Mule Deer Herd

Updated: Jun 29

   The Wisconsin Department of Natural Resources confirmed CWD in white-tailed deer in two more counties in April—Pierce and Waushara—which means at least 64% of the state’s 72 counties are now spreading the always-fatal disease.

   Even so, many Wisconsin hunters shrug and recite lines they taught each other when chronic wasting disease was first found east of the Mississippi River in February 2002: “Well, Colorado and Wyoming have had it for years, and their deer are doing just fine.”

   Then as now, such comments indicate willful ignorance.

   Yes, you can still find robust deer herds and good hunting in Colorado and Wyoming, but you can also find lousy areas that were recently excellent. For the details, read a June 24 article by Mike Koshmrl in the WyoFile (, which discusses a mule-deer herd so CWD-infected that hunters have nearly abandoned the area.

   Koshmrl’s article discusses a research project in the Wind River Valley by the University of Wyoming and Wyoming Game and Fish Department. Roughly 18 months ago, the researchers began following 40 mule deer fitted with GPS collars. Of those 30 does and 10 bucks, only 15 does and three bucks were alive a year later. After another three months (15 months into the study), only one buck remained.

   Most folks don’t need calculators to realize that’s a 10% survival rate for bucks.

   Koshmrl also reports that local hunters noticed the impact. In 2018, a hunter-satisfaction survey by Wyoming F&G found 80% of hunters were pleased with the area’s deer hunting. Hunter satisfaction fell to 40% to 50% the past two years.

   WF&G reports also show hunters quickly lost interest in the area. In 2020, the wildlife agency sold almost 500 deer licenses in Unit 157, the area’s core. Nearly 60% of hunters filled their tags, killing an estimated 201 mule deer. But in 2023, the agency sold only 126 deer licenses and less than 40% of hunters filled their tags.

   To summarize, the kill fell from an estimated 201 deer to 20. Again, you don’t need a hand calculator to realize that’s only 10% of the kill from three years before. 

   Likewise, when Koshmrl interviewed Ken Metzler, a local hunting guide, in late 2021, Metzler estimated his business had recently plunged 80%. After all, nearly every deer shot by his paying customers on agricultural lands he leased tested positive for CWD. No hunter, let alone a paying client with a $374 nonresident deer license, wants to walk up on a downed animal and find a sickly “flat-ass skinny” deer, Metlzer said.

   Metzler has since quit his guide business, telling Koshmrl: “I’m not booking any deer hunters. I can’t promise something that isn’t there.”

   CWD’s rapid spread in that area surprised everyone. Paul Cross, a research biologist with the U.S. Geological Survey, told Koshmrl that CWD seldom showed up in the area’s deer 15 to 20 years ago. But it jumped to over 60% infection rates the past 10 to 15 years.

   All deer killed in that area must be brought to a CWD check station. Test results from 2021 through 2023 show that 74% of mule-deer bucks and 41% of does killed by hunters had CWD. In effect, most deer shot by hunters were doomed anyway. No deer survives CWD, and few live two years once infected.

   In addition, one-third of the 18-month old bucks shot by hunters had CWD, which means they would have never lived to grow the big antlers all hunters admire.

   And just as old bucks with trophy antlers vanished from the mule-deer herd in Colorado’s Table Mesa area a few years ago, mature bucks also vanished from Wyoming’s Unit 157. Mike Miller, a CWD researcher with the Colorado Division of Wildlife, told Koshmrl: “They’re just not there.”

   Further, just like Wisconsin has experienced, many Wyoming hunters organized their opposition to pressure lawmakers to prevent experiments to fight CWD. In July 2023, Wyoming’s Game and Fish Commission rejected proposals to focus more hunting pressure on bucks, the deer most likely to spread CWD.

   Hank Edwards retired in 2023 after supervising the state’s wildlife health laboratory. Edwards told Koshmrl: “When I left the department, the majority of (WF&G staff) just had given up on doing any CWD management because it had gotten so combative. When you get to 65% prevalence, it ought to be bad enough that some of your detractors should at least let you try some things, but that hasn’t happened,” Edwards said. “How many people have to harvest a CWD-positive animal before the department is allowed to do CWD management on any of the herds in this state?” 

   You won’t find that answer in Wisconsin, either. Most hunters don’t want to know. A 2019 DNR study found only 9% of hunters statewide got a deer tested for CWD that year, and 70% have never tested a deer for CWD.

   CWD testing hasn’t been mandatory anywhere in Wisconsin since amateurs took over the state’s deer program after the 2010 governor’s race, and testing remained voluntary after DNR Secretary Cathy Stepp launched “new era” policies like “passive CWD management” in 2014.

   As a result, only 3,934 of 19,395 hunter-killed deer (20.3%) in 2023 in Wisconsin’s most infected counties—Dane, Iowa, Sauk and Richland—were tested for CWD. Of those 3,934 tested deer, 1,042 had CWD, an infection rate of 26.4%. At that rate, 5,121 deer in that four-county harvest could have had CWD, which means about 4,080 (80%) were eaten without a test. How many people eat venison from the typical Wisconsin deer? Well, the average Wisconsin household has 2.36 people, so it’s conceivable 9,626 people ate infected venison from those four counties in recent months.

   Wisconsin hunters can choose to ignore CWD and its impacts, but let’s not lie to friends and family, and tell them not to worry.

   Everything is not fine here, or in CWD’s home states of Colorado and Wyoming.

A Wyoming study of 40 mule deer in the Wind River Valley found chronic wasting disease killed half of the 30 does and 90% of the 10 bucks during the first 15 months of the study. — Patrick Durkin photo

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1 commentaire

2 days ago

Pat, After just reading your CWD Colorado article; Perhaps now you need to pull the essay I sent you out of your file and reconsider what I wrote . Rand Atkinson, Star Lake

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