December 31, 2013 at 5:55 pm #1886MikeKeymaster
White-Nose Syndrome Wiping Out New York Bats
Fungus decimates local bat population
Written by Matt Dalen
Thursday, 08 July 2010 00:00
It has become obvious to any observer of the night sky: There are fewer bats in the area than there have been in the past, and bat boxes are going unused. And while many factors are likely affecting bat populations, one major cause is obvious: white-nose syndrome, a fungus that has wiped out close to 90% of the little brown bats — up to now, the most common species in the area — in New York.
“We used to sit out [in the evening] and see a show of bats over the paddocks,” said Katonah resident Janet Harckham. “We would see dozens of bats swooping and eating insects. We have yet to see one bat this season.”
According to wildlife biologist Carl Herzog of the New York State Department of Environmental Conservation (DEC), white-nose syndrome has decimated bat populations by taking root in their wintering caves.
“In the summertime, they’re spread out all across the landscape, but in the wintertime, they congregate in a relatively few underground locations. That’s where the effects of the white-nose problem are apparent, and that’s where they die during the wintertime.”
Relatively new to science, white-nose syndrome was first detected in 2006 in a cave near Albany, when a caver photographed hibernating bats with an unusual white substance on their muzzles, according to the U.S. Fish and Wildlife Service. By the following winter, DEC biologists had found a few hundred dead bats in several caves in New York, and cases of the syndrome have now been found as far away as Oklahoma and Missouri.
Although the exact method by which the fungus kills the bats is still unclear, it appears to attack the bats’ body fat, and may keep the bats from having enough stored food to hibernate throughout the winter.
Affected bats have been seen flying during the day in cold weather, and often have visible white fungus on the bats’ noses, and sometimes on their wings, ears, or tails.
While Mr. Herzog said that all six bat species that spend their winters in New York have been found with the syndrome, they have reacted differently. Some populations, such as the big brown bat, appear nearly unaffected, and the big brown bat is likely the most common bat in the state now. Others, like the previously common little brown bat, have been decimated.
While no cases of white-nose syndrome have been reported in Westchester, Mr. Herzog said that was not surprising, as the fungus primarily hits the bats’ wintering grounds. He said that bats in northern Westchester, including Lewisboro, are likely to winter in New York caves, the nearest of which is an old mine complex in Kingston. Bat populations in that mine have declined by about 90% from several years ago.
Declining bat populations are likely to have effects across the ecosystem. Although they are largely credited with eating mosquitos, Mr. Herzog said that a larger issue may be an increase in moths, beetles, and other agricultural pests, which are larger and more likely to be eaten.
“Although bats do eat a lot of insects, we don’t really know for sure that there would be necessarily a change in insect abundance because they’re missing; we don’t have any baseline information of insect abundance from the pre-white-nose years,” Mr. Herzog said. “We just know so little about the bat issue from a quantitative perspective.”
He said that he was managing a project to track bat populations, by having volunteers drive around the state with detection equipment. That project is intended to track where different bat populations spend their summers, a question that has been largely unstudied.
Information: fws.gov or dec.ny.gov.
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