Most bats die from white-nose syndrome when the fungus irritates them in mid-winter, causing them to fly out of a warm cave into the deadly cold.
Researchers in New York and Vermont are still scrambling to understand the disease known as white-nose syndrome, a deadly fungus that has killed millions of bats since it was first identified near Albany, New York in 2006.
Caves in the Adirondacks, the Black River Valley, the Champlain Valley, and Vermont have been especially hard-hit.
One of the recent, most promising experiments is underway right now at a site in East Dorset, Vermont. Scientists there are hoping to use radio signals and marker tags to learn more about how white-nose is affecting the bats that have survived so far.
Dusk Arrives, Bats Get Busy
The work starts at dusk, when bats get busy. Alyssa Bennett, with the Vermont Fish and Wildlife Department, and Al Hicks, a wildlife biologist from New York, were on Aeolus Mountain in late afternoon, getting their gear ready.
Al Hicks said the research in Vermont could show how white-nose syndrome is killing bats, and whether some might survive.
Over the last half-decade, Aeolus Mountain has emerged as one of the most important biological sites in North America. Bats once gathered here -- hundreds of thousands of them from all over the northeast.
Now the area is a field laboratory for understanding white-nose syndrome. As we trekked up an old gravel road, Hicks said researchers have been stunned by the speed of this disease and its deadly impact. "Within the first year we knew that it was spreading very, very quickly," he said. In just seven years, white-nose has spread from a cave in Albany to sites as far away as Newfoundland, Canada, and sites in Illinois. "It hasn't slowed down. We're past the Mississippi River now."
Hicks manages his own company now, but in 2006 and 2007 when white-nose was first detected, he was a biologist for the New York State Department of Environmental Conservation. He has been on the front lines ever since, and he said the work being done here could provide big answers about how the fungus is killing bats and whether some animals might survive.
"It opens up almost an entirely different world," Hicks said. "Having the ability to identify an individual bat when it flies in or out of a cave -- it's huge."
Tracking Survivors With High-Tech Gear
A lot of this story is really depressing, but this part -- this experiment that scientists have begun at Aeolus cave -- is really cool. On the mountainside, Bennett took me down into the cave to show me how it works.
"This is guano hall, the main entrance of the cave," Bennett said. "You see on the floor all the remains of bones from the bats who have died here in the past. It's like toothpicks."
Researchers think as many as a quarter-million animals died at this one cave alone, a mortality rate of 90 percent. But not all the bats are gone.
Bennett played her headlamp over the rock ceiling. Tucked into the folds of stone were tiny gray bodies. "We have some small clusters of little brown bats hanging overhead here," she said.
More than half a decade after the mysterious disease first appeared in New York, researchers still don't know where it came from.
Here’s the cool part: researchers have rigged an antenna array and electronic equipment here near the mouth of the cave. The gear, protected under sheets of plastic, can actually detect individual bats going in and out of Aeolus Cave, keeping meticulous records of when they leave.
That matters because most bats die from white-nose when the fungus irritates them, or disturbs them in mid-winter. That causes the tiny animals to fly out of the warm cave into the deadly cold.
Will Any Bats Survive?
Back on the surface of Aeolus Mountain, Jonathan Reichard, with the United States Fish and Wildlife Service, said the death event here was so severe that it’s kind of a miracle there are any bats left at all. "It's a little bit of a curveball to think that there are still bats in there, a curveball in a great way," he said.
Reichard is assistant director of the federal white-nose syndrome response. He helped to set up the research camp, spreading tarps, and rigging lights. "Tonight, this group is trying to get a grasp of the survivors of little brown bats that are here," he said. The goal was to get a sense of whether populations have stabilized or, in some cases, are rebounding. "There's evidence that colonies may even be increasing at a light tick."
In order for that high-tech gear underground to work, scientists fix tiny tags on each bat. The tags register a coded blip when they pass through the radio signal.
By keeping a record of that traffic, Reichard said scientists will get a much clearer picture of whether these surviving bats are going to make it long-term. He said some species, including northern long-eared bats, have been pushed to the edge of extinction. "Through all of the mist-netting over the course of the past summer," he said, "at least four states didn't catch a single northern long-eared Myotis."
Those are four states where that one species of bat may be gone already.
On this night, researchers rigged a series of traps that captured surviving little brown bats. Hicks and his crew worked with head lamps to examine the animals one by one.
They checked for scarring from the fungus, and other signs of illness. They also checked for signs the bats are reproducing. After the physical was done, the tiny electronic tag was glued carefully to the bats’ backs, and they were eventually released.
As Goes Aeolus, So Goes the Rest of the Country
Hicks said the data gathered here this winter will inform what we can expect from other caves and other wintering sites as white-nose syndrome continues to spread across the continent. "It'll get out west, and hopefully by the time it gets there, we'll have more answers than we have now."
Here’s one last interesting note. More than half a decade after this mysterious disease first appeared in New York, researchers still don’t know where it came from.
The strongest suspicion is that it was carried from Europe on the boots or gear of someone who explores caves for a hobby. But the fungus has now been genetically fingerprinted, and efforts to find the original source around the world have failed.
This story was originally published at North Country Public Radio.
