MINNEAPOLIS - Wildlife crews will swoop down in helicopters above southeastern Minnesota early next year to capture and collar more than 100 deer to study how far they roam and what corridors they follow.
The chronic wasting disease (CWD) research project by the Department of Natural Resources is being launched with $350,000 in emergency funding to help stop the largest-ever CWD outbreak in Minnesota's wild deer population.
Starting this week, the DNR will be seeking cooperation from private landowners to carry out the work on hilly, forested land that rings Fillmore County's 371-square-mile CWD management zone. The zone was created last fall after routine DNR testing of hunter-killed deer discovered a cluster of infected animals near Preston and Lanesboro.
State wildlife researchers have joined the fight with a plan to net 115 deer and place GPS tracking collars around the animals' necks. Their urgent research funding request was accepted by the Legislative-Citizen Commission on Minnesota Resources (LCCMR), and the commission meets again this week to consider an additional grant of $552,000 in state lottery proceeds to extend the study for at least two subsequent years.
"It's an opportunity for researchers to get out in the very early phase of this outbreak to understand potential pathways" that CWD could travel, said LCCMR Director Becca Nash.
From region to region, deer disperse in unique ways from the territories where they were born, said DNR research scientist Chris Jennelle of the agency's wildlife health program. Data from deer-tracking collars will paint a real-life picture of dispersal patterns useful for setting meaningful boundaries for CWD surveillance and special deer herd management techniques.
Understanding how deer move across the landscape in southeastern Minnesota also will help computer scientists create predictive models of how CWD could spread, Jennelle said. The planned DNR study already has drawn interest and collaboration from the U.S. Geological Survey's National Wildlife Health Center.
"We want to be as precise as possible," Jennelle said. "It will help us fine-tune surveillance and potential management tools."
Michelle Carstensen, DNR's wildlife health program supervisor, said landowner participation is crucial because public land in the target area is scarce. The agency will soon distribute fliers soliciting volunteers and promising participants years of detailed data showing how deer congregate and move across their land. The GPS collars generally provide movement data for two years, and a total of 120 additional deer will be collared in 2018 and 2019 if funding is extended.
"People want to know what's happening on their 80 acres, and we'll share back the information," Carstensen said.
She said the study is important for the DNR to correctly manage the CWD zone, where a cluster of 11 hunted deer tested positive for the disease between November 2016 and March 2017. "We'll do our best to keep it from going to new areas of the state," Carstensen said.
CWD is a prion disease, similar to mad cow disease in cattle or scrapie in sheep, that affects deer, elk, caribou and moose. It's fatal to animals and there are no treatments or vaccines. Whitetails can carry the contagious disease for a year or more before developing symptoms of drastic weight loss, stumbling, drooling and listlessness.
There have been no reported cases of CWD infection in people. Recently, however, the Centers for Disease Control and Prevention intensified its CWD guidance by saying new studies have raised concerns that consumption of meat from a CWD-infected animal may be a risk to people.
CWD in deer and elk has become widely established in areas of Wisconsin, Iowa, Wyoming and other states, where some wildlife managers believe it will cause long-term decline of those game species. To justify the expense of the southeastern Minnesota deer movement study, the DNR told the LCCMR that the economic value of deer hunting in Minnesota is estimated at more than $500 million. About a half-million people a year hunt deer in the state.
Jennelle said deer in the study area will be captured starting in January, possibly through March. Helicopter crews will launch nets at the animals to immobilize them on the ground for ear-tagging and collaring. Each capture is estimated to cost $600, plus $250 an hour for spotter plane assistance.
The collars, costing $1,500 each, will expand to accommodate normal neck growth and neck bulging in bucks during the mating season. If the netting is ineffective, Jenelle said, field workers may shift to immobilizing deer with chemicals via dart guns.
According to the study proposal, 60 of the first 115 collared deer will be juvenile males born in spring 2016. More so than females of that age, males disperse from their natal range as they enter their second year of life. Adult bucks also roam, and researchers will attempt to collar 25 of them. The remaining collared deer in the first phase of the study will be juvenile female deer.
As part of the study in the second and third years, Jennelle said his research team would like to experiment with a few special GPS collars embedded with motion cameras. The study proposal also calls for mounting an array of trail cameras in the study area. Pictures will help researchers estimate rates of deer-to-deer contact useful for computer modeling of the spread of CWD, he said.