Madison – Wildlife experts have found early evidence that female white-tailed deer may migrate much farther than previously believed, a Wisconsin researcher said Monday.
The preliminary finding from a radio collar surveillance program in southwestern Wisconsin could have important implications for the spread of chronic wasting disease in the state.
Nancy Mathews, an associate professor of wildlife ecology at the University of Wisconsin-Madison, said researchers found an adult doe and her fawn near Black Earth that traveled about 5 miles toward the southeast this spring. Normally, does stay within a range of one square mile.
If does in southwest Wisconsin are moving longer distances, it could have “huge implications,” she said. “To have that kind of movement is suggestive of migratory movement.”
If that’s the case, infected does may be spreading prions, the infectious agents that are believed to cause chronic wasting disease, over much longer ranges.
Mathews made her presentation Monday afternoon to a panel of outside experts who are reviewing the Department of Natural Resources’ plan to fight chronic wasting disease.
Mathews and other researchers recently began a radio-collar surveillance study of white-tailed deer in the 411-square-mile eradication zone near Mount Horeb where the first wild whitetails turned up infected with the deadly disease last year. So far, the DNR has tested nearly 40,000 deer and found 190 infected with chronic wasting disease – all inside or near the zone.
Movement of does is important because white-tailed deer live in matriarchal social groups of does and fawns. Those groups may be refuges for chronic wasting disease infected deer that are visited by adult males during the mating season.
Whether bucks are spreading the disease as they visit the groups is not known.
The UW researchers hope to find out more about the spread of the disease and about the social habits of whitetails in the area as their radio-collar study continues this summer.
In other presentations at Monday’s two-day symposium, which continues today, researchers said they’re trying to determine whether the fatal brain disease is more prevalent in male deer. Research on western mule deer suggests bucks are twice as likely to have the disease as does.
Mike Samuel, a UW wildlife researcher, said it’s too early to say whether that will prove true in Wisconsin. It’s not simply a matter of counting the gender of the 190 wild deer found infected so far in Wisconsin, since there are many other factors that play a part in the study.
Staying the course
In a related matter, Tom Hauge, the DNR’s director of wildlife management, said the agency has no plans to abandon its plan to kill as many deer as possible in the so-called eradication zone near Mount Horeb.
Earlier Monday, DNR Secretary Scott Hassett said he wants to induce more landowners in the eradication zone to participate in the agency’s efforts to halt the disease. One way to do that, he said, is not to use the word “eradication” to describe the DNR’s efforts to cull the herd.
Though Hassett said there has been no policy change on efforts to reduce the deer herd, he hopes to get landowners in the zone, who have resisted killing any deer on their land, to join the effort.
“People were very upset by the term ‘eradication’ and probably getting more excited than they should at this point,” Hassett said.
“Because there’s so much research going on and so many questions that aren’t answered, why scare everybody by saying we’re going to eradicate? That might be the long-term plan, but we can only take out x amount of deer each year – 20% or 30%,” Hassett said.
Hauge said with continued intensive surveillance and continued deer kills in the zone, it might be possible to eliminate chronic wasting disease without killing every deer in that area.
And John Cary, a UW computer modeling expert, said at Monday’s symposium that failure to do anything to wipe out the disease will likely result in the entire state’s deer population becoming infected in coming decades.
Computer modeling has showed that – under ideal circumstances – eradicating the Mount Horeb-area deer herd could wipe out chronic wasting disease in Wisconsin in as little as six years, Cary said. He added, however, that computer modeling is not an exact science and that eliminating the disease in such a short period of time is based on other variables, including the level of cooperation from landowners in the zone.
While the Natural Resources Board is not scheduled to take up the subject of eradication at its two-day meeting that starts today, the board is expected to vote Wednesday on a contentious subject – the baiting and feeding ban instituted by the DNR last year.
A total of 52 people have already signed up to speak, a record for a Natural Resources Board meeting. Several board members are at odds with the DNR over baiting and feeding and are considering lifting the ban in northern Wisconsin.