Mystery disease spreads, threatening bat population
CAPITAL REGION A mysterious ailment that killed thousands of hibernating bats near Albany last winter has spread to a cave in Schoharie County and one in Vermont, authorities said Wednesday.
Wildlife officials are asking people to stay out of caves with bats in them until the situation is understood. Cavers in the town of Cobleskill found bats exhibiting symptoms tied to the illness in early January, and the discovery in a Vermont cave indicates the illness has spread to a 110-mile radius beyond the Albany County caves where between 8,000 and 11,000 bats were first discovered dead from the ailment last year.
The U.S. Fish and Wildlife Service is working with wildlife officials in New York and Vermont while those in surrounding states watch for developments that could threaten entire populations of bats, including the Indiana bat that’s listed as an endangered species by federal and state authorities.
“Nobody has ever seen this before, nobody has seen a [bat] mortality event such as this of any cause,” said Alan Hicks, a mammal specialist in the endangered species unit at the state Department of Environmental Conservation.
There are two signs that point to the illness. Bats both alive and dead were found with a white fungus-like substance around their noses. It’s unclear if the substance is the cause of the disease or a symptom.
And when examined, pathologists learned the bats had depleted all of their body fat earlier than normal, making it impossible for them to survive throughout their typical hibernation.
Authorities do not know if the ailment can affect humans, nor is it clear how it is spreading.
Hicks said the threat to the bats is so great because they don’t breed very quickly. Bats have one pup per year, he noted.
The population of bats in the Cobleskill cave was at 1,300 in 2006 and reduced to 470 during 2007, Hicks said.
“This year there’s 38 bats there. Half of them are dying [from the white-nose syndrome],” Hicks said.
Last year, dead bats exhibiting the ailment were found in four caves near Albany, Hicks said. The symptoms are visible among bats in one of those caves this year, he said.
“The bats haven’t started dying yet in large numbers this year, but they’re following exactly the same trends they followed last year where a very large percentage of them died,” Hicks said.
One of the caves near Albany is home to about 100,000 bats during hibernation; another houses about 50,000, Hicks said.
“We’re talking a lot of bats that are in immediate danger.”
The nationwide nonprofit Center for Biological Diversity this week called on the U.S. Fish and Wildlife Service to shut down access to caves because of the chance the “white-nose syndrome” could be responsible for the disappearance of about 700 Indiana bats from a cave near Albany last year.
According to the DEC, about half of the estimated 52,000 Indiana bats that hibernate in New York do so in one former mine, and that site is now infected with white-nose syndrome.
The ailment is killing at least four bat species so far: Indiana bats, eastern pipistrelle, northern long-eared and little brown bats.
The little brown bats, which people in the Capital Region may notice flying overhead at dusk in the summer, have suffered the brunt of deaths identified so far, according to the DEC.
Leigh Haynie, an attorney at the Center for Biological Diversity’s Vermont office, said Indiana bat populations in Vermont and New York were considered “bright spots” in the survival of the endangered species, following declines in bat numbers as great as 200,000 in Kentucky and Missouri between 1960 and 2001.
Haynie said since it’s still unclear whether humans are spreading the illness or whether it could impact the health of humans, the federal government should close down the caves and withdraw any permits for people to take bats.
In addition to their work eating mosquitoes and other bugs, bats are also used to gauge the impact of contaminants as it relates to mammals, Haynie said.
Internet resources suggest a little brown bat can eat 1,000 mosquitoes in an hour, and they also eat cucumber beetles and other pests that destroy agricultural crops.
“It’s not just one species of bat, it’s several species of bats are being killed and exhibiting these signs,” Haynie said.
“They don’t know what to do. It’s coming out of nowhere. So they don’t know what it is. They don’t know how it spreads. So there’s a lot of confusion and concern,” Haynie said.
U.S. Fish and Wildlife Service spokeswoman Diana E. Weaver on Wednesday said the agency can only close caves on property it owns and possibly property owned by other federal agencies, and none of the impacted caves are on federal property.
“The states, obviously they have the lead on what they’re doing and we’re working with them,” Weaver said.
Bats are believed to hibernate roughly from November to April, and some dead bats were found by residents during the winter in Altamont last year, Hicks said.
The fact that the bats were out during the winter and found with no fat reserves suggests they woke up and tried to go out for food, Hicks said.
But bats primarily eat flying insects, which aren’t out in the winter, and they’re so small they wouldn’t likely survive due to the cold and need for energy to find food, Hicks said.
Cavers are being credited with noticing the strange illness and dead bats, but it’s unclear still whether cavers themselves could be spreading the illness.
“There’s only two avenues of spreading it; one of it is us and the other is the bats themselves,” Hicks said.
Local caver Emily Davis, a member of the Northeastern Cave Conservancy, said Wednesday caves owned by the conservancy and by the National Speleological Society have been shut down to cavers that keep in touch with their organizations.
But she said there are still others who aren’t part of the organized caving community who might not know to stay out of the caves where the bats are hibernating.
Davis said the winter isn’t the most popular time to go caving, though some people may be disappointed to learn they’re being asked to stay out of caves with bats.
Two local caves have low numbers of recorded wintering bats, Davis said, so there are some options for those who want to go exploring this winter.
“Anybody interested in caving in the area really needs to be checking in to make sure that we follow what DEC wants until we figure out what’s happening with this white-nose fungus,” Davis said.
More information can be obtained on the Web site of the state Department of Environmental Conservation at http://www.dec.ny.gov.