Wisconsin's wolf population stalls after years of growth
Wisconsin's wolf population stopped growing over the past year after steady growth for more than a decade.
The Department of Natural Resources reported Tuesday that the state's estimated population is between 537 and 564 wolves, down just a tick from the 540 to 577 wolves estimated one year ago.
It's the first time since 1983 that the wolf population didn't make a clear increase and only the second decline since the wolf population study began in 1979, when 25 wolves were counted in the state.
The news wasn't unexpected. In April, Adrian Wydeven, the DNR's wolf biologist, told the News Tribune that mange may be having a bigger effect on wolves than in past years and probably had caused the population to shrink some.
On Tuesday, the DNR reported that a new form of mange, demodectic, was detected in a Wisconsin wolf this past fall. Only sarcoptic mange had previously been detected in Wisconsin wolves. Mange is a skin disease caused by a burrowing mite that can lead to death by exposure during cold months. Several radio-collared wolves died from severe mange over winter.
Wydeven said the population also may be stabilizing because wolves have colonized most of the best habitat in the northern half of Wisconsin. Efforts by wolves to expand their range now often are rebuffed by other wolves.
The annual winter wolf survey uses aerial tracking of radio-collared wolves as well as snow track surveys by DNR and volunteer trackers. Also included are wolf sightings by the public.
Wolves were confirmed to have caused livestock damage on 30 farms across the state last year. Problem wolves are being trapped by government trappers and killed in the state after wolves in the Great Lakes were removed from federal protections in 2007. A total of 37 wolves were trapped in 2007 near where livestock had been attacked, along with one wolf-dog hybrid, the DNR reported.
In addition, the DNR issued shooting permits to 25 landowners with recent wolf problems in 2007, but no wolves were shot. Three landowners did shoot wolves in the act of attacking pets or livestock on their property without permits, as is allowed under Wisconsin's wolf management plan.
There are an estimated 143 wolf packs in Wisconsin, most in the northern half of the state.
Minnesota has about 3,000 wolves while Michigan's Upper Peninsula has about 550.