Killer found in New England's largest bat cave
Tue, Mar 24 2009 at 4:56 PM
By The Nature Conservancy
White-nose syndrome, first discovered in New York last winter and blamed for the death of thousands of bats, has now spread to caves in Vermont and Massachusetts. Bat biologists surveying the Conservancy’s Mt. Aeolus Bat Cave in Southern Vermont returned with disturbing news.
Wildlife biologist and Vermont bat expert Scott Darling recently visited the Conservancy’s Dorset Bat Cave on Mt Aeolus and returned with devastating news. “Many bats displayed the now-standard characteristics of an affected cave. Bats, which should have been hibernating at this time of year, were flying just outside the entrance. Dead bats were observed on the snow, and many clusters of bats were gathered near the entrance.”
The Dorset Bat Cave, protected by the Conservancy in 1983, was later discovered to be the largest bat over-wintering site in New England. Population estimates range from 20,000 to 30,000 and include six species - the federally endangered Indiana, the state threatened Small Footed, the Little Brown, Big Brown, Northern Long-Eared and Eastern Pipistrelle.
At this time of year bats should be much deeper in the cave where the temperature is stable. Researchers are trying to determine if the syndrome, named because of a distinctive white fungal growth on the nose of affected bats, is the cause or a symptom of a weakened immune system and death.
“While researchers work to identify the cause of the illness and how it is spread we must do everything we can to ensure the health of the survivors,” said Rose Paul, Director of Science and Stewardship for the Vermont chapter. “In late spring female bats move to warmer areas, like the Champlain Valley, and form maternity colonies to raise their young.”
Protecting bat populations requires the conservation of both subterranean winter hibernation sites, and summer habitat in mature forests and river-side corridors. Many bat species, including the federally endangered Indiana bat, breed in Vermont each summer. Their survival depends on the availability of roost trees that offer two key advantages – shelter and warmth. Taller trees and those on the edge of woodlands catch the sun, warming their sleeping inhabitants, and mature trees with loose bark, rotten areas, cracks and crevices provide needed shelter. Shagbark hickory, a species once prevalent throughout the valley, are a preferred location as their loose bark naturally provides ideal hiding places.
Landowners can help bats by leaving dead snags in their woodlots and allowing trees to mature. Just one small bat can handsomely repay the hospitality, by eating as many as 1,200 mosquitoes and other insects each night. All cave visitors have been asked to stay out of caves until May 15th or until research is able to pinpoint the cause of the illness and how it is transmitted. Larger caves like the one on Mt Aeolus are gated, a practice which protects both hibernating cave inhabitants and human adventurers from harm.
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