Experts say bat population will be slow to recover
"The decline for bats has been so dramatic and it continues. They're still dying here," said Wildlife Technician with the Vermont Fish and Wildlife Department Alyssa Bennett. "Recovery is not something that we would see in our lifetime."
Some of the species that were not as heavily impacted by White Nose Syndrome, such as the Big Brown Bat, may have "a good chance of stabilizing at some point," Bennett said. However, some may not recover at all and others - such as the Little Brown Bat or the Northern Long Eared Bat - could be threatened with local extinction, Bennett said.
Impeding the recovery process of the bat population is the fact that they are very slow to reproduce. Most of the species found in Vermont only have one "pup" per year, Bennett said. Adding to the problem is that their mortality rate is very high at 50 to 60 percent in the first year. After that, Bennett said the bats have to try to survive the winter when they are susceptible to White Nose Syndrome.
Jim Hand - who sat on the Vermont Chapter of the Nature Conservancy Board until 2010 - said that while he did not know the specifics in terms of numbers, it was estimated that between 90 to 95 percent of the Little Brown Bat population, which occupied the Dorset Bat Caves were affected by White Nose Syndrome.
"I remember taking trips up to the caves during those winters when there were large numbers of them out on the ground, out on the snow," said Hand. "In most cases there were predatory birds waiting for them to die."
White Nose Syndrome is caused by a fungus called Geomycesdestructans, which thrives in the moist, cold conditions of the caves and mines where bats are typically found.
"The theory is that it might of been transported inadvertently by humans that enter into cave or mine environments because bats don't travel across the ocean from Europe to the U.S.," said Bennett. "The fungus can attach to clothing and stay viable on clothing for a while."
In an effort to prevent the spread of White Nose Syndrome, the Vermont Fish and Wildlife Department has been closing caves and mines so that it will not be spread by humans.
"Because we believe this is an invasive species ... the protocol has been managing the spread of invasive species," said Bennett. "In Vermont we actually have two sites that are closed even to bats entering so that we can study if the fungus continues to thrive even without the bats as a host."
Bennett said there are some caves that have been closed to humans, but that allow bats to gain entry. Then there are other caves, she said, that are voluntarily closed - meaning signs have been posted requesting that people not enter.
Since the emergence of White Nose Syndrome - which Bennett said really began to hit Vermont hard in 2008 and 2009 - approximately 500,000 bats have been lost statewide.
A negative side effect of the decline of the bat population - and one that could have long reaching effects - is an increase in the number of insects. "Those bats are eating a lot of insects that are annoying to us, like mosquitos, to major agricultural pests like Cucumber Beetles," said Bennett. "Insects like mosquitos are also carrying diseases. Another potential disease could spread and if we don't have natural insect control like insect eating bats I suspect there would be a rise in pesticide use and I suspect there would be a rise in our food [costs] because of that."
Bennett said White Nose Syndrome has been found in 19 states throughout the U.S. as far south as Alabama and west of the Mississippi and that it has also been found in the provinces of New Brunswick, Nova Scotia, Ontario and Quebec in Canada.
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