The Berkshires used to be home to as many as eight species of bats -- but for the last three years, the only species Rene Laubach has seen is the big brown bat.

White nose syndrome, an epidemic fungal disease that in 2006 made its first domestic appearance in Albany, N.Y., has ravaged the others.

Laubach, a bird, bat and butterfly expert who directs the Berkshire Wildlife Sanctuaries for the Massachusetts Audubon Society, estimated a 90 to 99 percent mortality rate among all bats except big browns, which still dipped by 40 percent, he said.

"There are bound to be effects, from a public health and agricultural standpoint," Laubach said recently. "A major insect eater cannot disappear from an ecosystem without something changing. There's not anything around to take their place."

Infected bats, identifiable by a white fungal growth around the muzzle, rouse during hibernation and starve as a result of winter activity. Since 2006, more than six million bat deaths in the Northeast are attributed to white nose.

Did the Berkshires seem buggy this summer? Each individual bat can consume 600 insects per hour, according to Mass Audubon Society. The creatures prey on mosquitos, moths and other night-flying insects.

"Every million bats consume 700 tons of insects," said Julie C. Blackwood, assistant professor at Williams College. "This is incredibly important to the farmer, who's the natural enemy of pest insects. Natural insect suppression is valued somewhere between 4 and 50 billion dollars per year in the United States.

"[The death toll due to white nose] amounts to 80 percent of the population of hibernating bats in the Northeast. It's absolutely devastating."

Blackwood, a mathematician, constructs models that describe bat movement in order to stem the spread of bat-borne pathogens like rabies and better understand phenomena like white nose.

Blackwood, who gave a well-attended presentation on her research recently at The Log on Spring Street in Williamstown, said researching the disease can help biologists decide whether methods exist to prevent it from wiping out entire species, like the little brown bat, now predicted for regional extinction by 2020.

These methods could include barring certain caves, culling or fungicide treatment.

"These pathogens are incredibly important to study," Blackwood said.

On top of his own observations, Laubach said residents have noticed and reported to him on bat shortage and bugginess in the county in recent years.

Laubach has a bat preservation effort, leading a bat house making workshop, planned for Saturday, March 29, at Pleasant Valley Wildlife Sanctuary from 1:30 to 3 p.m.

To reach Phil Demers:
pdemers@berkshireeagle.com
or (413) 281-2859.
On Twitter: @BE_PhilD