Big flocks of bats could be a thing of the past in Pennsylvania because the state's hibernating species have been ravaged by white-nose syndrome.

The numbers aren’t all in yet, but the decline in Pennsylvania’s bat population has been so steep that one Game Commission biologist said the commission has moved into “survivor management.”

In July, biologist Cal Butchkoski told the Pennsylvania Board of Game Commissioners the state’s formerly numerous hibernating bat species, such as the little brown bat and the big brown bat, have been ravaged by white-nose syndrome, a condition that has killed millions of bats in 22 states since it was discovered in New York in the winter of 2006.

To gauge the impact of white-nose syndrome on the state’s bat population, the commission launched a bat count in June of the state’s maternity colonies.

Stephanie Taylor, an environmental education specialist at Moraine State Park, said the bat count there was completed in June and the findings were bleak.

“Out of eight boxes and two bat condos in the park,” said Taylor “only one bat condo had 500 bats in it, and at one time it had 4,000.”

The bat condo, a large wooden structure on stilts, is behind Mount Zion Baptist Church at the park, said Taylor.

“It was down to 500, that was all we found in the whole park,” she said.

Taylor said the results of the statewide survey have yet to be tallied.

Becky Lubold, an environmental education specialist at Jennings Environmental Education Center in Brady Township, said the bat condos serve as maternity colonies in the summer.

“The bats in the bat condos are maternity colonies that come back in the summer to raise their babies,” Lubold said.

“Babies are born by mid to the end of July. When the babies begin to fly, they disperse from the maternity roost by the end of August, fly around and visit caves and abandoned mines,” said Lubold.

It’s in these caves and mines where the hibernating bats contract the white-nose syndrome, said Lubold.

The condition is caused by a fungus that thrives in the cold, wet environments of the underground spaces used by hibernating bats.

The fungus grows on a bat’s nose and also on its wings, ears and tail.

“It is not the fungus that kills the bat but the lack of food,” said Lubold.

She explained the fungus interrupts the bat’s hibernation cycle.

“It affects the hibernating bats,” Lubold said. “They begin scratching their faces, they wake up and have to look for food.”

“They wake up many more times than normal. They don’t have a lot of energy stored up. They emerge from hibernation early, hungry and dehydrated,” Lubold said.

The U.S. Fish and Wildlife Service says bats flying in the daytime or in temperatures below freezing may be affected by the ailment.

“White-nose has affected some our species in different ways,” said Lubold. “The big brown bat is not as affected, but the tricolored bat, that bat is really being affected. It’s the first in and the last out of the caves.”