Connecticut’s rarest bat is endangered. A court order now protects it
One of Connecticut's rarest animals, the northern long-eared bat, won endangered species protection in federal court recently. The bat species faces extinction due to the devastating effects of white-nose syndrome.
“It's time to go out and ensure the act does what it's intended to do, which is protect the species,” said Ryan Shannon, senior attorney for the Center for Biological Diversity. “The bat's numbers are so depleted that we need to take every single step we can to ensure the species can survive while we find a cure for white-nose syndrome.”
The northern long-eared bat was once one of the most common bats in Connecticut and North America, likely numbering in the millions. The New York Department of Environmental Conservation estimates that before 2005 there were at least 500,000 of these bats across New York state. But the onslaught of white-nose syndrome in 2006 crashed the population. Over 95 percent of northern longeared bats have been lost to the fungal infection.
Devaughn Fraser, a wildlife biologist with the state Department of Energy and Environmental Protection, said, "We don't have exact numbers, but they were one of our most common of our Myotis species." She explained that prior to whitenose syndrome, these bats were so common that nobody had really thought to do a formal census of them. “Now they are our most rare,” she said.
These bats were initially listed as “threatened” under the Endangered Species Act in 2015, but the protections offered to the bats were slim. Although the bats were not to be disturbed while hibernating, the U.S. Fish and Wildlife Service permitted many habitat-disrupting activities, like timber harvest, near hibernation sites and maternal colonies.
“Part of the problem was that the rules put in place basically meant no protections for the bat,” said Winifred Frick, director of conservation science for Bat Conservation International. “I think the decision to list the species as endangered is fully warranted, and I'm relieved to know we will now have the full protection of the ESA. This species desperately needs it.”
The Center for Biological Diversity sued on behalf of the bats in 2015. The legal process took until the end of November to force the reclassification of the bats as endangered.
“We thought this [white nose] warranted an endangerment finding,” Shannon said. “This is an existential threat.”
Shannon said delays in endangered species protection had become common. A study published this year in the journal PLOS found that the Department of Fish and Wildlife, which administers the Endangered Species Act, is slow to list species, often waiting until their populations are critically low.
“I think the biologists working on [endangered species] are doing a pretty good job,” Shannon said. “But their work goes through this long and torturous review process with dozens of steps of internal reviews up and down from regional directors to D.C.”
Fish and Wildlife did not comment when asked about listing decisions and the case of the northern long-eared bat specifically.
The Case of the Bat
Northern long-eared bats are small, forest-dwelling and nocturnal. They forage on insects in the hours just before dawn and just after dusk. During the summer and spring, they roost in trees. Mother bats will gather in small colonies, roosting together as they nurse their young.
In the fall, the northern long-eared bats gather to mate and migrate to hibernation caves. Baby bats are born the next year. Unlike other cave-dwelling bat species, northern long-eared bats are less likely to cluster up in dense hibernation colonies, preferring to nestle deep into cervices solo or in small groups. In the most northern parts of their range in Canada, these bats can hibernate for up to nine months.
“They look for tunnels, underground environments that are sequestered from temperature fluctuations in the outside environment during winter,” Fraser said. “They want it steady and cold. Not so cold that they freeze. Not so warm that they can't reach that nice hibernation state.”
White-nose syndrome is caused by a soil-dwelling fungus accidentally tracked into caves by hikers in the late aughts. The fungus is indigenous to Europe and grows in cold environments at temperatures perfect for bat hibernation. When bats hibernate, their immune systems also functionally shut down.
“The fungus grows into their tissues because their immune system is shut off,” said Gary McCraken, University of Tennessee professor emeritus and bat biologist. “It only gets purchase in them because they're immune compromised.”
Bats infected during the summer and autumn can fight off the infection. The fungus is lethal to bats while they are immune-suppressed in deep hibernation. McCraken explained that as the fungus infiltrates the body, bats repeatedly wake up from deep torpor, burning through their fat reserves. The bats starve to death.
Some bats survive to spring but are left with widespread skin lesions and torn wings. While some bats might recover at this point, many suffer from deathly shock as their immune system suddenly reawakens to fungi all over the skin.
“The immune system wakes up, and it sees this foreign body that's infected it,” McCraken said. “There's a huge immune shock, probably similar to a cytokine storm.”
The cost of white-nose syndrome in the ecosystem and agriculture of North America has been immense. Bats are our best allies when it comes to insect control, consuming millions of pounds of bugs every year. Those bats also fertilize forests and fields with their guano and pollinate native flowers. They are vital to a thriving ecosystem and agriculture, providing billions of dollars in ecosystem services annually.
“There's many unquantifiable benefits for bats,” Fraser said, citing bat guano distribution across forests, rivers and fields. “They play roles that we haven't been able to quantify.”
Endangered species protection is key to protecting the bats that remain. While the northern long-eared bat wasn't made endangered by bat-unfriendly activities like wind farming or forestry, it's important that these things not harm the few bats that remain. Surviving bats need the chance to recover. Colonies of northern long-eared bats persist in Connecticut and across the sound on Long Island. Those bats could repopulate the region if allowed to grow.
“I have an undying commitment to optimism,” Frick said, citing how other endangered species had come back from the brink. “I refuse to give up.”