Deadly Bat Disease Arrives in Michigan

Apr 10, 2014

A little brown bat from New York State with white-nose syndrome.
Credit Ryan von Linden/NY Dept. of Environmental Conservation / U.S. Fish and Wildlife Service

Several bats in northern Michigan have turned up with a white-nose syndrome. It's the first time the condition, which has killed millions of bats in other states, has been found in Michigan. 

The state Department of Natural Resources announced Thursday that this spring, researchers found five bats from three counties – Dickinson, Alpena and Mackinac – which showed signs of the disease. Laboratory tests confirmed that it was white-nose syndrome.

Afflicted bats often have patches of white fungus on their noses, wings or other parts of their bodies. Scientists are still studying whether the fungus is the cause of the sickness or the result of another infection.  But according to the DNR, the condition is thought to be responsible for a 70 to 80 percent drop in the summer bat population in parts of the Northeast, where white-nose syndrome has been observed for several years.

The state has had an action plan for the disease in place since 2010, says spokesperson Dan O’Brien, adding that this appearance was not a surprise.

“We’ve been surrounded by the disease for a couple of years now,” he says.

The state will close mines and other hibernation sites on public land in Northern Michigan. That’s to prevent people from accidentally spreading the fungus and exposing more bats, and to protect habitats from disruption.

The more “disturbed” the bats are, “the higher the mortality rates,” O’Brien says.

So far the disease has not been found in bats in southwestern Michigan. Researchers with Eastern Michigan University checked a hibernaculum (bat enclave) in Berrien County and did not find signs of the disease among the individuals there.

They were unable to evaluate a hibernaculum in Hillsdale County because no bats were there when they visited.

O'Brien says anyone who finds a dead or injured bat should avoid handling it since that could expose them to rabies. People can report "die-offs" to the agency by phone or on its website.