Earlier this year, a working group of biologists came out with a grim estimate: More than 5.7 million bats in North America have died from a mysterious, fast-moving disease known as white-nose syndrome. Several bat species may be on the brink of extinction. And their die-off is being described by some as "the most precipitous wildlife decline in the past century." Conservation groups are now working to get them added to the Endangered Species list. And as Susan Sharon reports bats in Maine have not been spared.

This past winter, Acadia National Park biologist Bruce Connery started getting dozens of reports around Mount Desert Island of a strange phenomenon: bats flying around in the daytime, landing on sunny roads, rooftops and carriage paths to warm themselves and acting as if they were hungry or sick.

These are nocturnal creatures that should have been hibernating in the colder weather and that shouldn't have been out foraging before dark.

"A few did fall and we collected those. And those ones that were collected died within 12 hours," Connery says. "And then in February we sent those off to the National Wildlife Health Lab, which is in Madison, Wisconsin."

Connery says the four bats, all identified as little browns, were emaciated. They didn't have any body moisture and their wing membranes had retreated to the point that they could barely fly. All four were found to have the fungus known as white-nose syndrome.

One of them was a juvenile born in the summer months that hadn't had a chance to visit a winter hibernacula, a large cave where bats congregate and where the fungus is known to be especially aggressive in humid, cool conditions. In some caves in the Northeast, white-nose syndrome has wiped out more than 80 percent of bat populations.

But Connery says this youngster hadn't been to a cave. And that is a new concern.

"When the fungus really was started it was sort of thought that it was going to just sort of be staying in areas where there were these huge hibernacula," he says. "Well, what happened when we found our situation, and what we think may be happening at these other coastal situations, is that spores are actually able to stay on the bats and they're able to actually transfer it to other individuals."

While Maine may not have many large hibernacula, the decline of bats here has been more rapid than anticipated, says biologist Susan Gallo of Maine Audubon. This summer her group put out a call for citizen volunteers to help gauge bat productivity around the state. But Gallo says she quickly realized that it no longer matters whether bats are having babies or not.

"Right now, what matters is they're already in huge decline--much bigger than we expected," Gallo says. "Because when we went to find these maternal roost colonies, what we're finding is that they're just not there. People who've had the colonies for decades at their house, at their farm and their barn--they're just not showing up at all this year."

One of those people is Margaret Barrow, who lives in central Maine and has two bat houses attached to the side of her barn and her shed. "You can see the different chambers, the chambers, and they go up in those chambers," she points out. "But you can also see there's no droppings up there, unless there's something left over from years ago."

Normally this time of year, Barrow says she and her husband delight in standing on the edge of their porch and hearing dozens of mother bats moving around the bat house nursery on a hot afternoon and chattering to their young. In the evening, she says she's counted more than 100 as they head out in search of food.

But this year, except for a few stragglers that later died, Barrow has not seen any healthy bats. And that worries her. "I personally think if we don't have bats, which we probably don't right here at this spot right now, the insects will--in this kind of location they're already unbearable--they'll become UNbearable," she says, emphasizing the first syllable. "I mean bats have a valuable service to offer."

A single bat can consume more than 1,000 mosquitoes a night. And biologist Susan Gallo says she and some of her colleagues are starting to wonder what may happen to the spread of mosquito-borne illness if bats disappear altogether.
Pat Rawson, of Mount Vernon, says she finds it terrifying to watch such a dramatic decline of a species in her own backyard.

"I've lived her for 34 years and there have always been bats," Rawson says. "I could stand outside and count hundreds and hundreds and hundreds. Last year I didn't have as many as I had in the past. This year I saw one bat and it was during the day, which wasn't a good sign."

Gallo says it will take years for imperiled bat species to be listed under the Endangered Species Act and in the meantime she's counting on Mainers who have remnant bat colonies to let her know where they are.

Get more information about Maine Audubon's bat survey.

Learn more about bat conservation efforts.