The Wonderful World of Connecticut's Bats

            Bats have a bad reputation. They’ve been described as “rats with wings” and are thought to get caught in peoples’ hair and have poor eyesight, none of which is true.

            “Their reputation hasn’t been helped by the media and horror movies,” said Jenny Dickson, a wildlife biologist and bat researcher who serves as director of the Wildlife Division at the Connecticut Department of Energy and Environmental Protection. “Making bats out to be scary is a Western culture thing. In the Far East, they’re symbols of good luck and are good to have around.”

            Bats are actually good to have around in every part of the globe. According to Dickson, they eat huge quantities of pest insects and are especially important to farmers, who rely on

Eastern red bat

bats as a form of natural insect control for their crops. In some parts of the world, they also pollinate trees and flowers and disperse seeds.

            While monitoring the populations of the nine species of bats found in Connecticut, Dickson also works to educate the public about the value of bats and to dispel myths about them.

            “I’ve seen a perception change in the last 30 years,” she said. “The more people learn about them and the more we separate myth from fact, the more people realize that they’re not something to be frightened of after all.”

            Dickson divides Connecticut’s native bats into two groups: tree-roosting bats that typically migrate south for the winter, and cave bats that hibernate in caves and mines.

            Hoary bats, silver-haired bats and red bats are the state’s three tree-roosting species, which don’t usually gather in large numbers and are seldom seen flying over backyards or urban areas. Because they migrate to the South, they remain active all winter, feeding on insects and roosting in tree cavities or behind peeling bark.

            Six species of cave bats are found in Connecticut – big brown, little brown, northern long-eared, Eastern small-footed, Indiana and tri-colored.

            “They like to fit into tight places, so they’re much more likely to be associated with manmade structures – hiding under eaves, under shutters or in barns,” said Dickson. “They use natural places as well, like tree cavities if they can find one, but they’re mostly around suburban and urban environments. And they travel long distances to find a good place to hibernate for the winter, sometimes 100 miles or more.” Some hibernate in caves in western Connecticut, while others go north to caves in New York and Vermont.

            In the mid-1900s, Indiana bats and small-footed bats disappeared from Connecticut when many bat caves – called hibernacula – were sealed up and the bats killed because they were thought to be major carriers of rabies. Because bats typically give birth to just one pup each year, they reproduce very slowly and can take decades to recover from population declines. It wasn’t until the 1990s that Indiana bats returned to the state, and small-footed bats didn’t reappear until 2010. Both species – along with northern long-eared bats and the three species of tree-roosting bats – are on the state’s list of rare species. The Indiana bat is also on the federal endangered species list.

            The biggest threat to populations of cave bats is white-nose syndrome, a disease caused by a fungus native to Europe that has spread to hibernacula in North America and is responsible for killing many millions of bats.

            “The long-eared, little brown and tricolored bats have been devastated by white-nose syndrome,” said Dickson. “Those were our most common species, next to big browns, until the fungus arrived. Now the long-eared has declined by 99 percent and little browns and tri-colors have declined by 95 percent. Big browns have declined, too, but only by 30 to 40 percent.”

            The disease causes the bats to awaken in the middle of winter and use up their stores of energy at a time when insects are not available to feed on.

            White-nose syndrome isn’t the only threat facing local bat populations, however. Habitat loss is also a major concern, and it is unknown how the changing climate will affect them.

            To monitor and protect Connecticut’s bat populations, Dickson and her colleagues spend a great deal of time surveying hibernacula to detect changes in populations, finding and monitoring maternity colonies, and conducting what she calls acoustic sampling.

            “We drive a 20-mile route in different parts of the state with a big microphone on the roof of a car that digitally records all the bat calls, and then we analyze those calls to determine what bats are actively foraging in those areas,” Dickson explained. “It helps us identify hotspots and identifies places to do more investigation. It’s enabled us to get a lot more information on species that are hard to detect.”

            Despite gaining so many new insights on local bat populations, Dickson said there is still a great deal that is unknown. And that’s what she likes about studying bats.

            “I’m always learning something new about our bats because they always do things that are unexpected. They’re absolutely fascinating animals,” she said. “Once you have a chance to see them up close and work with them, you realize they’re not at all like the hype that surrounds them. They’re inquisitive, curious and a lot of fun.”

This article first appeared in the fall 2019 issue of Connecticut Family.