Cold War Bunkers Converted to Bat Caves to Fight Deadly White Nose Syndrome

Bat populations devastated by the killer "white-nose syndrome" are being offered a novel and unnatural form shelter at a Maine wildlife reserve, but bat populations are still struggling to survive.

The Aroostook National Wildlife Refuge has been in operation since the 1990s after it went out of use as an Air Force base at the end of the Cold War, and now scientist have converted two of the base's 43 nuclear bunkers into artificial hibernacula for bats.

Since it was first recorded in the U.S., white nose syndrome has killed an estimated 6.7 million bats. Because bats typically hibernate in ecologically diverse surroundings, it is not easy to treat their caves against white nose syndrome without disrupting the natural environment, which is a hurdle for the scientists tasked with disease management.

"We cannot go into a natural cave or mine that has a lot of diversity - a lot of naturally occurring fungi - and then spray some sort of chemical," Ann Froschauer, an endangered species biologist and US Fish and Wildlife Service and white nose syndrome spokeswoman, told the BBC.

"But in a human-made structure, like a bunker, we can go into a site like that [after the bats have left] and we can actually scrub a place down."

In December 2012 USFWS staff relocated 30 male little-brown bats to the bunker. Unfortunately, only nine bats in the artificial colony survived the winter, though it was unclear whether it was white nose syndrome or other conditions that killed the bats.

"Hibernation is something we are getting a lot better handle on but we do not really understand all of the things that are going on," Froschauer told BBC News.

"It is tough to hibernate bats and make sure we have all the right conditions - there are a lot of challenges."

Froschauer said that the scientific consensus was that white nose syndrome is here to stay and that to save bat populations the best hope is to find ways to manage the disease, as eradication seems unlikely.

"We will never see bat populations in the eastern US and Canada at pre-WNS levels in our lifetimes, or for generations afterwards," she warned.

"Our best bet now is to work towards how we can contain the disease while we are working on the science side of things and the other things that could interrupt the cycle of the disease and allow us to work towards the conservation of bats."

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