BATS

HARTFORD -- Connecticut's pest-eating bat population has essentially collapsed, meaning higher costs for farmers and probably more mosquitoes at summer picnics.

The state Department of Environmental Protection on Tuesday released winter-time census information showing that White Nose Syndrome has killed off 95 percent or more of winter colonies in Northwestern Connecticut caves.

One cave where 3,300 bats were counted in 2007 had only seven-to-12 bats during a recent count. Another cave, where there were as many as 1,800 bats in 2007, had a population of only about 69.

"We're rapidly getting to the point of no return, unfortunately," said Jenny Dickson, the DEP's supervising wildlife biologist, warning of a possible statewide extinction before the end of the decade.

"This is really an unprecedented level of decline in a wildlife population," she said of the disease, which has no human health ramifications.

During a morning news conference in DEP headquarters, Dickson joined Commissioner Amey Marrella in asking state residents to report locations of summer bat colonies and whether they return.

Even if it's only someone's attic or barn, the agency wants to know the reach of the invasive fungus, which somehow migrated from Europe and is now killing bat colonies as far west as Missouri.

There are several species of cave-dwelling bats that seem most adversely affected by the fungus, including the little brown bat, the northern long-eared bat and the tricolor bat, but other species also have contracted the fungus, which appears in cold weather as a white mold-like substance that can cover the mammals.

"The effects of the fungus are just devastating," Marrella said.

"In one of our other locations we estimated the decline in population of about 95 percent from what it was three years ago," Dickson said. "Statewide, most of our sites are seeing declines from 95 to essentially 100 percent."

Similar reductions in neighboring states mean that summer populations of the pest-eating bats are expected to be very low. The syndrome has recently been discovered in Canada, western Tennessee and the Great Smoky Mountains.

Bats are generally long-lived and with only a litter of one pup per year, their numbers are slow to recover. The little brown bat can generally live 35 years, she said, while others can live 15 years in the wild.

The ones that have not contracted the fungus might just be lucky.

"I think a lot of it depends on where they're been roosting, where they forage during the summer, what bat-to-bat contact they've experienced," she said, noting that big brown bats seem not to be as affected by White Nose Syndrome. "They do contract it and it is killing them, but not as fast as it is some other species."

She said that scientists don't know how to deal with the fungus, which joins the ecosystem of caves, so the application of fungicide could kill other naturally occurring organisms.

"You're going to inadvertently have impacts that you hadn't intended," Dickson said, adding that the result of winter experiments on possible fungicide treatments have not yet been concluded.

"Whether it's the fungus itself that kills them or whether the fungus triggers other responses in the bat that then ultimate kills them, that's the part that we're not sure about," she said.

Other studies involving federal, state and local authorities in cooperation with research universities, remain active. The syndrome can affect wing membranes and may cause enough of a collapse of bodily functions to slowly starve the animals.

"What tends to happen as a result is that the fungus either triggers an irritation in the bats or it causes the bats to awake at times they shouldn't during hibernation," Dickson said.