Mosaic Habitats

Turtles and Grouse               Bats

BatsClimate Change Symbol

Quick Summary - dash x x


Cave-dwelling bat species have declined catastrophically as indicated in the chart below that contrasts the monitored population in 2007 with recent years.

Graph of bat population 2007


The chart above depicts the winter population of three cave-dwelling bat species monitored annually by the Department of Energy and Environmental Protection (DEEP). (The number of sites monitored by DEEP has declined since 2007 because so few bats remain.)
An epidemic fungal disease called white-nose syndrome (WNS) is the primary cause of the bats' demise. WNS has been documented in at least 33 states since its first appearance in New York in 2006. All but one Connecticut bat species are listed as endangered or of special concern.
The catastrophic decline in bat populations, which is not confined to cave dwelling species, has raised concerns about the future of bats in the state. Recovery, if one occurs, will be slow: adult female bats usually produce just one pup per year. Of the nine species native to Connecticut, only the big brown bat is not categorized as a species of special concern or as endangered; however, its population has also declined. In 2015, the big brown bat was added to the list of species of Greatest Conservation Need in Connecticut's Wildlife Action Plan.
The absence of bats from Connecticut's evening air will be a boon to the nocturnal moths and beetles that continually threaten to infest forests and crops. Bats also eat mosquitoes, a number of which carry diseases that affect humans, birds, horses and other animals. Nationally, bats feast on insects each night, adding up to more than $3.7 billion worth of pest control each year. Though seldom seen, bats play big ecological roles.
Not all bats live or hibernate in caves; many inhabit trees. If data become available, future editions of this report will contain information on the tree-dwelling species (three of which are on the list of species that are of special concern. They are not represented on the chart above)
The goal for bats is for recovery of all nine species to a stable, sustainable level.