White-nose Kills Hundreds Of Bats Near Abandoned Mines In Pennsylvania

Game Commission biologists had been uncovering signs of what appeared to be an impending WNS outbreak in Pennsylvania since last spring. Over the past two years, the disorder has killed more than 90 percent of some wintering bat colonies where it first surfaced in New York and spread through New England. Its confirmation in Pennsylvania and New Jersey came in the past two weeks, but Pennsylvania had a surprisingly unique distinction among the states where WNS has been documented; Pennsylvania bats were not leaving their wintering quarters – caves and mines – and weren’t dying. Unfortunately, that no longer can be said.

Last week, bats were found dead outside of an abandoned mine near Carbondale by a citizen who later reported the findings to the agency. Game Commission Wildlife Conservation Officer Chris Skipper visited the site immediately and confirmed the findings. Bats were dead on the ground; flying from the mine; dropping from the sky. Then on Groundhog Day, agency biologist Greg Turner found bats flying from another Lackawanna County mine near Throop. They shouldn’t have been emerging for another six weeks.

“Roughly 50 percent of the bats in the mine near Carbondale displayed the characteristic white fungus,” said Kevin Wenner, an agency biologist stationed at the agency’s Northeast Region office in Dallas. “Bats have been and are staging close to the entrance of the mine; some dying in the mine while others were flying around and dying outside on top of the snow.  The bases of several trees near the mine entrance had piles of dead bats around them.  Hundreds were visible on top of the most recent snow, so I suspect there are thousands of dead bats.”

The findings in Lackawanna County are not unexpected, according to Game Commission Executive Director Carl G. Roe. But they do portend a disturbing and uncertain future for cave bats east of the Mississippi River and quite possibly beyond.

“The Game Commission has worked hard to stay abreast of White-Nose’s escalating presence in Pennsylvania,” Roe said. “Our bat biologists have been actively involved in field monitoring and research and are working closely with some of this country’s best and brightest minds in biology and epidemiology in their pursuit of clues. But a year later, there are just as many questions about WNS, and more dead bats.”

A couple weeks ago, the National Wildlife Health Center in Madison, Wisconsin, informed the Game Commission that bats it submitted from an old iron mine in Mifflin County had tested positive for a cold-loving fungi found on many bats diagnosed with WNS. The bats were discovered by Dr. DeeAnn Reeder, a biologist with Bucknell University, and Turner during ongoing field investigations into bat hibernation patterns that included weekly monitoring for the disorder’s presence in several Pennsylvania hibernacula. During this work, dozens of bats had a fungus appear around their muzzles and on wing membranes, while many others relocated from warmer, deeper areas of their hibernacula to areas close to the entrance, or failed to arouse during hibernacula disturbances.

Turner reported that he found the health of hibernating bats deteriorating in the abandoned Mifflin County iron mine near Shindle during his weekly visit with Dr. Reeder. Fungus was advancing on bats that had it and appearing on more bats – now about 50 percent of the colony. But, more important, dead bats were found in the water that flows through the mine.

“This mine may be the next hibernaculum where bats ‘fly and die,’” Turner said. “There’s a good chance bats are leaving other hibernacula instate and dying on the landscape, but we haven’t found them yet.  That is why we are asking for the public’s help.”

Currently, researchers still are unsure exactly how bats contract WNS and how it initially and, ultimately, affects a bat’s body. They cannot confirm whether the fungus appearing on some bats is a cause or a symptom of the disorder. New York and New England have lost tens –maybe even hundreds – of thousands of bats to WNS over the past two years.

Lisa Williams, Game Commission biologist, said the public can help the agency better understand the distribution of WNS by reporting sick-acting or dead bats they find while out and about this winter.

“We’re not asking people to go out of their way to help, but if you hike or walk or drive along back roads, and encounter dead or dying bats, we’d really like to hear from you,” Williams said. “Please don’t go in caves or mines or underground. And do not handle bats – dead or alive – and keep children and pets away from grounded bats. Even though there currently are no known human health implications associated with WNS, the Game Commission would prefer that people not handle any bats; we’ll take care of all of that. We just need residents to let us know if they find something suspicious.”

There are two quick and easy ways to report sick-acting or dead bats this winter. The first is by calling the nearest Game Commission region office. The second is by using the Game Commission’s “Report Sick Bats” form that can be accessed in the left-hand column of the agency’s homepage (http://www.pgc.state.pa.us).

Wenner also reported another interesting finding while investigating the state’s latest WNS site.

“It’s important to realize that once the bats leave the mine, the fungus is not very visible as moisture and flight seem to wear it off the bat,” Wenner said. “So, simply looking at a bat for white fungus will not necessarily confirm whether it is a clean, WNS-free bat. That’s why all bats should be left where found and reported to the Game Commission.”