This Halloween, spooky plastic bats probably will outnumber tiny northern long-eared bats. The voracious insect-eaters are being lost to a killer fungus — except on Long Island’s East End.
Scientists are trying to solve the mystery of why this bat species, in a few coastal areas — including the East End, Nantucket and Martha’s Vineyard — has not entirely succumbed to white-nose syndrome, the disease that has killed millions of their kind since it was discovered in the northeast in 2006.
On the North and South Forks, a trio of these survivors, Mario, Raphael and Tony, have been captured, weighed and swabbed to see if they have caught the fungus. They then are outfitted with transmitters that weigh just a little more than a raindrop; even a stick of bubble gum is a little heavier than these small, furry mammals.
Samantha Hoff, a PhD student in SUNY Albany’s Ecology and Evolutionary Biology program, said she and her lab partner, Casey Pendergast, a master’s candidate, are researching where the bats spend their time, what they eat, how active they are, whether they have found places to hibernate, and whether they are infected with white-nose syndrome.
The bats’ genetic structure also is being studied, according to the U.S. Fish & Wildlife Service, which is collaborating with the state Department of Environmental Conservation in the research.
New York State and the U.S. government protect the northern long-eared bat as a “threatened” native species, which means they likely will soon be in “imminent danger” of extinction.
Mario has become Hoff’s favorite: “He’s been the most consistent and easiest to find so far,” she said.
That is no small task: the three bats tend to head in different directions, and finding them requires aiming a heavy antenna skyward and rotating it — either while hiking through underbrush or driving, with the antenna held out the window.
“We get a lot of funny looks,” Hoff said.
“Whenever we are out, setting up mesh nets or tracking, usually people are interested to hear, and kind of happy to hear, that their community is special,” because some of these bats are making it on the Island, she added.
At dusk, when bats come out to hunt insects, the team sets up exceptionally fine mesh nets where their acoustic devices pick up their calls, which are at much too high a frequency for humans to hear. “Just because we can detect them doesn’t always mean we are able to capture them,” Hoff said.
Like dolphins, bats rely on sonar or echolocation to "see" the world around them. Possibly, that is why the accompanying video of the team gently releasing a northern long-eared bat shows it pausing as it ascends lavender-gloved fingers before taking flight with wings nearly three times longer than its body.
“These guys are pretty chill, I would say,” Hoff said. “A lot of other bat species I’ve handled — obviously, they are probably scared — we’re a large animal that has captured and is handling them.”
Northern long-eared bats seek places to hibernate that have high humidity, shelter from any breezes, and temperatures that stay about 45 degrees, according to the U.S. Fish & Wildlife Service and other experts. Crevices, hollows in trees, barns or sheds — and crawl spaces, sometimes to the surprise of the homeowners — all will do. When the team discovers a bat might have found a home on private property, they talk with the owners.
“It’s something we try to tread lightly with — again, a lot of people aren’t very warm to bats to start with [but] we’ve had a lot of luck in terms of people being interested in our research,” Hoff said.
The official term for fear of bats is chiroptophobia. Though very few bats have rabies in this area, some people find them creepy — hence their popularity at Halloween — though the only ones that feed on blood live in Latin America, experts said.
White-nose syndrome apparently came from Asia or Europe, where bats seem to withstand it, experts said. The white-nose fungus, unfortunately, thrives in very places bats like to hibernate — and it does well in cold weather, unlike others of its ilk. Once it has infected a hibernation site, “it essentially just waits for the bat to come and start growing on the bat,” Hoff said.
One reason the fungus might be so deadly, Hoff said, is that it grows under the bat’s skin, and is so irritating that it frequently rouses bats from hibernation, just when they should be benefiting from the way their metabolisms slow to conserve energy.
“Every time they wake up, they are burning the fat they stored,” she said, which means infected bats basically starve to death. Even healthy bats lose almost half their weight during hibernation, experts said.
In coastal areas, bats seem to spend less time hibernating, Hoff said, which might help protect them from the fungus. Upstate, most hibernate or enter torpor from Nov. 1 to April 1, but on Long Island, the period may run from late November to early March.
The shorter hibernations might be a result of the Island's more temperate ocean climate. And therefore there might be more insects for them to catch, offsetting the fungus’ calorie-burning effect, Hoff said.
To help keep them from becoming extinct, scientists ask homeowners to avoid clearing forests and axing dead trees — unless they pose a danger — and instead of using pesticides, relying on bats, which can devour hundreds of bugs in an hour.
People also can build bat boxes. For instructions how, check the U.S. Fish & Wildlife Service website.