From Wisconsin Department of Natural Resources
-- For the second year in a row, a statewide survey of more than 100 known bat wintering sites has found no signs of White-nose syndrome, a deadly disease that has killed more than 6.7 million bats in the Eastern United States and Canada.
"Neither the fungus nor the disease was found in Wisconsin," according to David Rendell, bat ecologist. Bats are voracious insect eaters, helping keep crop and forest pests and mosquitoes in check. A recent national study estimated the insect-eating services that bats provide between $658 million to $1.5 billion alone for Wisconsin's agricultural industry.
To determine if the disease was present in Wisconsin caves and mines with wintering bats, the DNR bat surveillance crew searched 114 sites for signs including a fuzzy white fungus on the nose, mouth and ears of hibernating bats, and unusual behavior like bats hibernating near cave entrances where it's colder or bats flying outside during the day during winter.
The sites searched represented 95 percent of the known underground locations and was one of the most extensive surveillance efforts in North America, Redell said. The sites had been identified by DNR crews last year from among 800 potential sites searched and determined to have bats present and conditions suitable for the fungus.
Redell believes that the arrival of the White-nose syndrome in Wisconsin is still imminent, since the disease was detected along the Mississippi River corridor, but the delay has provided the "great benefit of time."
"The more time we have for research to understand how this disease spreads throughout populations of bats, the better able we can assess options that may possibly slow down the arrival and devastating effects of the disease," Redell says.
The delay also has given DNR staff time to work with private landowners to help them take voluntary steps to keep the disease out of caves and mines, with commercial tourist cave operators to educate visitors about the disease and prevention steps and for recreational cavers to learn how to decontaminate their gear to avoid accidentally spreading the fungus.
White-nose syndrome, so-called because the fungus leaves a powdery white fuzz on hibernating bats' noses, ears and wings, kills 70 to 100 percent of bats in contaminated caves. It was discovered in New York in 2006 and has since spread to 16 states and four Canadian provinces.
In January, the U.S. Fish & Wildlife Service estimated that 5.7 million to 6.7 million bats had died from white nose. Bat populations are susceptible to decline because of low reproductive rates -- mothers typically give birth to just one pup per year -- and white-nose syndrome has been particularly deadly to bats.
Wisconsin has one of the highest concentrations of hibernating bats in the Midwest. Some bats from neighboring states of Illinois, Indiana, Minnesota, Iowa and Michigan—up to 300,000 bats—spend winters here so any disease affecting Wisconsin's hibernacula has far reaching impacts on the summer landscape.