Researchers seek remedy for bat disease

Michigan Department of Natural Resources A little brown bat sports an identification band which will help researchers track its movements.

HOUGHTON — Scientists are targeting abandoned area mines, in an effort to eliminate white-nose syndrome in bats.

“White-nose syndrome is a devastating disease,” said Maartin Vonhoff, a professor of biological sciences at Western Michigan University, who was part of a team working in abandoned Ontonagon County mines a couple months ago. “It’s killed millions of bats in eastern North America already. And so, there’s been a huge effort by state and federal biologists, by academic biologists, to try and come up with treatments that will make a difference and save the lives of bats.”

White-nose syndrome is named for the pale-colored fungus found on the wings, noses, ears and tails of infected bats, according to the Michigan Department of Natural Resources. Infected hibernating bats, awakened prematurely by the disease, may lose their reserves of fat needed for the winter. Some have been seen flying outside their caves in the middle of winter. With no insects available to feed on, and stored fat diminished, these bats die.

The team is field testing chitosan, a type of fiber taken from the shells of crustaceans and insects that acts against white-nose syndrome.

“It prevents the fungus from growing. It also has wound-healing capabilities so it speeds up the healing of wounds,” Vonhoff said. “We’re hoping that chitosan will limit the growth of that fungus and will limit the extent of damage to the tissues of the bats and thereby increase their survival.”

Michigan Department of Natural Resources Little brown bats flying inside a mine in Dickinson County, which was gated, allowing the bats to come and go, but keeping humans out.

Scientists found about 40 little brown bats and a lone northern long-eared bat inside Firesteel adit, a horizontal mine passageway.

They put the bats collected individually into small paper bags, and took them to the tables outside the mine where they were sexed, weighed, measured and tested.

“We’re going to swab their skin to see whether they have the fungus on them that causes white-nose syndrome,” Vonhoff said. “And then we’re going to give them either the treatment of chitosan or we’re going to treat them with a, we call it a control solution, so it’s got everything in it except for the chitosan.”

Application of these substances will allow the researchers to test whether treatment of the bats has any impact on their survival. We’re going to put them back in the mine and then we’re going to come back in the spring and we’re going to see how many of them are alive.”

Bill Scullon, a field operations manager from Michigan Department of Natural Resources’ Norway office, said each bat was uniquely tagged and will be followed.

“Even modest reductions in the normally very high white-nose syndrome induced mortality rates can have significant positive implications of species recovery over the long term,” Scullon said.

A second treatment project applies a chemical agent to the inside of mines or caves, in hopes of killing the fungus present before bats return to hibernate.

“Chlorine dioxide is used to kill all the fungal spores throughout an entire mine during the summer before bats return for the winter,” said Baraga MDNR wildlife biologist John DePue. “The theory is that this will clean the site and reduce infection rates and subsequent mortality below what would otherwise be expected.”