“At this point in time, we just don’t know what is killing these bats,” said Scott Darling, wildlife biologist for the Vermont Fish and Wildlife Department.   “We really don’t have a handle on what the cause of this problem is.”

The syndrome first appeared last year in several caves in Albany, N.Y., where an estimated 11,000 bats were found dead or dying.  This year, white nose syndrome has been seen in caves across the northeast, decimating bat populations in the area. 

“If the initial fatality estimates of 95 percent are accurate, and we have half a million bats hibernating, you are looking at hundreds of thousands dead,” said Darling.

In Hailes Cave in New York alone, bat populations have declined from 19,000 two years ago, to 7,000 last year, to just 1,200 in February.  Many of the dead were Indiana bats, listed as an endangered species.

Samples of ailing, dead, and currently healthy bats from the region have been sent to labs and health departments around the country for testing.  Viruses and fungus are suspected causes, and immunologists are exploring all options.

As for the tell-tale white fungus around affected bats’ noses, “it appears it’s not the fungus that’s killing them, but it’s taking advantage of their weak immune systems,” said Peter Youngbaer, vice president of the Northeastern Cave Conservancy.  “We’re seeing that the fungus is getting into their glands and upper respiratory systems.”

The loss of so many bats in the northeast could spell big trouble for the region’s farming industry.  Bats, particularly the four species of bats affected by white nose syndrome (Indiana, Little Brown, Northern Long-eared and Eastern Pipistrelle) feed on insects and beetles, often eating up to their own body weight in insects each night. 

“These are great predators in the northeast.  Just as birds eat all these bugs by day, that’s what bats do by night.  Without them we’d be overrun by bugs,” said Youngbaer.  “That’s the stuff that’s going to destroy crops.”

With more than 9 million acres of farmland in New York, Vermont and Massachusetts alone, the consequences of a massive bat die-off may be significant.  Parallels can be seen between the bat syndrome and the recent colony collapse disorder of American bees.  Last year, tens of millions of bees suddenly disappeared, costing the national farming industry an estimated $8 billion to $12 billion in losses due to lack of crop pollinators.  Many of the same experts are reportedly consulting on both issues.

The full extent of the loss of bats on agriculture remains unclear because white nose syndrome and the massive bat die-offs have never been seen before.  “It’s hard for us to tell (the long-term impact) because we’re witnessing almost an ecological experiment on what happens when you take away a nighttime predator,” said Darling.

It may take considerable time for bat colonies in the northeast to bounce back from the syndrome as well.

“Bats tend to live 25 to 30 years.  They birth typically one pup per year.  If they die, it’s a long process to get colonies back to pre-white nose levels,” said Youngbaer. 

Precautions are being taken to protect against further spread in the area.  All caves containing the bats have been closed to the public, and cave explorers are being asked to keep out until at least May.  Scientists are unsure whether the syndrome is being spread by the bats themselves or via humans, who take it with them on their clothing and gear from one cave to another.

In the meantime, state Fish and Wildlife Services have asked the Northeastern Cave Conservancy to create an online log (http://www.necaveconservancy.org/add_wns_data.php) for cavers, asking anyone who visited the original sites of contamination since January 2007 to report it. 

“It’s a trail for us to look at,” said Youngbaer.  “It’s key to disproving the fact that people might be moving it around.  That will get caves open sooner.”

- As originally reported on Medill News Service, March 4, 2008