"They appear to be dying of starvation, and when you feed them, they seem to recover," said Merlin Tuttle, founder of Texas-based Bat Conservation International, a nonprofit that funds bat research.
Tuttle considers the condition the gravest threat to bats in the 40 years he has studied them. He is trying to organize a national scientific conference in June so experts can share what they know and come up with ways to address it.
"This could become a major national issue," he said.
White nose syndrome has been detected in the little brown bat, the eastern pipistrelle and the northern long-eared - all species common in Maryland, according to Limpert. The endangered Indiana bat also is affected, but she said that species is extremely rare here.
"It's just really puzzling and troubling," Limpert said.
There is nothing known to stop the condition's spread, and anyone venturing outdoors this spring could see its effects because many bats here each summer have migrated from winter hibernating spots up to 200 miles away, experts say.
If bats are dying elsewhere, there will be fewer to migrate into Maryland and devour the insects that trouble area gardeners and farmers.
Most bats also produce only one offspring a year, so it will take a long time for populations to recover from massive die-offs.
"These die-offs could have consequences down the road we're not anticipating," said Kimberly Williams-Guillen, an ecologist at the University of Michigan.
In studies published Friday in the journal Science, she and Kalka found that bats and birds eat comparable numbers of insects.
Kalka's work focused on bats that feed on insects in trees in the understory of a tropical forest in Panama. Williams-Guillen examined the effects of bats on insects on coffee plants in Mexico.
In Maryland, the DNR has been conducting annual surveys for years to track the bat population in caves and mines in Western Maryland. This year's count turned up no evidence of white nose syndrome. But wildlife officials remain concerned. "It is in the back of our minds," said Dan Feller, the DNR naturalist who conducts the survey.
Wildlife officials in several states, including New York, New Jersey and Vermont, are asking spelunkers to stay out of caves where bats roost while scientists research the condition.
