HINESBURG — The Vermont Fish and Wildlife Department reported on Tuesday that data from the 2022 field season confirm the national conservation significance of a large summer colony of Indiana bats in the northwestern part of the state.
Indiana bats are a federally endangered species. The colony, located on conservation land in Hinesburg, consists of over 700 bats.
“This finding is exceptional because we have not documented a surviving summer colony of over 100 Indiana bats in Vermont since the devastating declines caused by White-nose Syndrome in 2008-2009,” said small mammal biologist Alyssa Bennett.
“In Hinesburg this field season, we counted as many as 300 bats in a single roost,” Bennett continued. “That is similar to historic numbers at this site and three times greater than anything we have found in Vermont over the past decade.”
In addition to its size, two other factors make the Hinesburg colony especially important as biologists continue to study the Indiana bat’s response to White-nose Syndrome and work to sustain and recover the species.
First, bats in the Hinesburg colony are making use of bat houses. This is unusual for the species across its range and has not previously been documented in Vermont. In addition, bats were tracked back to large tree roosts on conserved land. Bennett says this is evidence that habitat improvement efforts made more than a decade ago may be paying off.
Second, Indiana bats are found in the Midwestern to the Eastern US—Vermont’s Champlain Valley represents the northeastern extreme of their range. The Hinesburg colony is the most northeasterly known population of Indiana bats, which have only been found summering below 1200 feet in Vermont.
However, climate change modeling for this species suggests that as lower elevations warm, the species may be pushed further northeast and to higher elevations.
“This colony’s size, use of bat boxes and persistence at the extreme of the Indiana bat’s range means there may be new opportunities for conserving this species in Vermont and the northeast,” says Bennett. “Are Indiana bats moving further north and east as summers become warmer? Are there other colonies that could benefit from habitat improvement? Thanks to this year’s findings, these are the questions we’ll be working to answer in 2023.”