Iron Mountain Bat Cave
© Theresa Peterson/Daily News Photo
Bill Scullon of the Department of Natural Resources replaces a sign at the Iron Mountain Bat Cave. DNR officials are watching the spread of a new disease affecting bats in the eastern U.S.

Approximately 50,000 bats that make their home in the Millie Hill mine could be in danger if a deadly disease, called white-nose syndrome, makes its way to the Midwest.

The disease's name comes from the distinctive white smudges that appear on the noses and wings of infected bats. Researchers at the U.S. Geological Survey's Wildlife Health Center discovered that the smudges are actually a previously unknown fungus that thrives in the cold of winter caves.

However, no one seems to know whether the smudges are the cause of the disease or just a symptom.

White-nose syndrome causes bats to rouse more than usual and deplete their stores of body fat that they need during hibernation, said Bill Scullon, wildlife biologist at the Michigan Department of Natural Resources (DNR) office in Escanaba.

Scullon has researched the mysterious disease and been involved with surveillance of bat populations in Michigan. At this time, no outbreaks of white-nose syndrome have been observed west of Pennsylvania, he said.

The disease was first detected in 2007 in New York and Vermont, but it has since spread to New Jersey, Pennsylvania, and West Virginia.

"Michigan does not have white-nose syndrome, but it's still a big concern," said Scullon. "The species that have been infected out East are the same species that we have here in the Upper Peninsula."

According to Scullon, the Millie Hill bat cave contains big brown bats, little brown bats, and Northern long-eared bats.

"The syndrome is pretty devastating," he continued. "In some cases, the mortality rate in infected caves is around 95 percent."

Although white-nose syndrome poses no health threat to humans, a drop in the bat population could cause an increase in the number of insects that destroy crops. The bat species in the Millie Hill bat cave typically consume larger beetles, flies, and mosquitoes, said Scullon.

Despite extensive research, experts still do not know what causes the disease or how to treat it. If the white fungus indeed causes white-nose syndrome, some experts have suggested lowering the humidity in certain caves to inhibit fungus growth. However, that plan could create problems for other species in the caves.

Others have looked at the possibility using a fungicide or fungus-killing bacteria.

In the mean time, researchers continue to collect data and measure bat populations.

Scullon encouraged area residents to report any outdoor bat sightings during the winter months, when the animals should be hibernating.

"Bats should not be outside at this time of the year," he said. "Anyone who finds a bat outside, like in a snowbank or something, should contact the DNR immediately and not touch the bat."