It’s been more than a decade since white-nose syndrome hit Connecticut and at least one expert said it would take several decades more for bat populations in the state to bounce back from the damage done.

“Bats live for a very long time but typically only have one or two babies each year, depending on the species,” said Jenny Dickson, director of the wildlife division at the state Department of Energy and Environmental Protection. “It would take decades to rebound the population this badly hit.”

White-nose syndrome — which targets a bat’s nose, wing membrane and tail membrane — is believed to have made its way to the United States from Europe. It has killed nearly seven million bats in the United States and Canada.

The fungal disease thrives in cold, damp areas — like caves — and infects bats during hibernation.

The fungus can eat away at a bat’s wing tissue, causing it to wake up during hibernation and burn away stored fat reserves. Then, when the insect-eating bat ventures out, it often struggles to find food and won’t survive the remaining months of winter.

White nose syndrome was found in New York in 2007. Mortality rates started to register in Connecticut at the beginning of 2008.

“Between 2008 and now, it’s had a devastating impact on cave bats,” Dickson said.

The Mine Hill Preserve in Roxbury used to be home to “well over 3,000 bats” before white-nose syndrome was found in Connecticut, Dickson said. But once it hit, that overall number dropped to less than a dozen in just three years.

Some of Connecticut’s most common bats are among those most affected by white-nose syndrome: the little brown bat, the northern long-eared bat and the tri-colored bat. Dickson said the big brown bats have also been harmed, but not to the same extent.

She said the northern long-eared bat has seen well over a 95 percent decline because of white-nose syndrome. She said the species was classified as “threatened” a few years ago but is now “endangered” in Connecticut.

“The northern long-eared bat used to be found in every town in the state,” Dickson said, adding that now the species’ population is dwindling.

“This species went from incredibly secure to threatened,” she said. “Now it’s almost impossible to find ... We’ve only had one confirmed report of breeding in that species in the last 10 years — just this year. That was a huge discovery for us. That was a species we were really concerned about.”

The little brown bat has shown evidence that the species is still reproducing, but still that population has declined well over 90 percent. The tri-colored bat has been “dramatically impacted” by the fungal disease as well.

“The most drastic drops were in the first five years,” Dickson said. “That’s when we really saw populations kind of hit the bottom. We really haven’t seen populations increase at all.”

The state’s population of big brown bats has seen a 35 to 40 percent mortality rate because of white-nose syndrome.

The challenge now is trying to figure out what can be done to prevent white-nose syndrome from potentially wiping out specific bat species in Connecticut — and beyond.

“There are a couple of things that have some promise,” Dickson said. “We’ve found (the fungus) doesn’t do well at higher temps or in UV-light conditions.”

For now, DEEP’s Wildlife Division spends time monitoring bat populations and tracking reported sightings.

DEEP was involved with installations of bat gates in caves across Connecticut.

“This was one of those things that really helped prevent any additional disturbance to the bats in the winter,” Dickson said.

The most important thing DEEP has worked to do is raise awareness.

Dickson said the fungus got its name because the fungal bloom is white in color, so often people think that’s what they should look for in potentially infected bats.

That’s not always the case.

If a resident spots a bat out and about during the winter months when it should be hibernating, that’s the first red flag.

But bats won’t always have a white, fuzzy mark on their nose right away after contracting white-nose syndrome so it’s not immediately visible to the naked eye.

“We’ll get people who say, ‘well, I saw one, but it didn’t have the white on the nose,’” Dickson said. “That doesn’t mean the bat is OK. Just seeing a bat that looks OK doesn’t mean it is OK.”

DEEP’s Wildlife Division also wants to hear from residents who have maternity colonies of bats in their yards during the warmer months so they can keep track of what bats are surviving.

“One of the things we can do is talk about it and talk about how important bats are to our ecosytem,” Dickson said, adding that they provide insect control. “Bats matter. They make a difference in our lives.”

Connecticut residents are urged to report bat sightings to DEEP’s Wildlife Division.

If a dead bat is found, residents are asked to put on gloves, double bag the bat and put it on ice or in a freezer and call 860-424-3011 for further instructions.

Residents can find links to a public bat sightings form at https://bit.ly/2NYlyvQ. Photos can be emailed to deep.batprogram@ct.gov.

Connecticut Media Group