Encouraging Signs for Bats at the Nan Williams Conservation Area

This year, FLT continued its work to protect wildlife habitat at a former soapstone and talc mine located in the Nan Williams Conservation Area (NWCA). This mine had been a historic hibernaculum – a site where wildlife takes refuge – for three species of bats. During a 2008 survey, 148 little brown, northern long-eared, and tri-colored bats were recorded overwintering in the mine. By 2015 however, that number had dropped to zero. The past decade has seen a dramatic decline in bat populations in the northeast and elsewhere, due in part to species-specific health problems such as White Nose Syndrome (WNS) that disturb bats’ ability to hibernate effectively.

After Franklin Land Trust acquired the NWCA in 2018, we took steps to protect the mine as a vital wildlife resource. With the help of a grant from the US Fish and Wildlife Service administered by the Wildlife Management Institute, FLT installed a bat-friendly gate at the entrance to the mine. This custom gate, fabricated and installed by Sanders Ecological LLC, was designed to allow both air flow and bat access while preventing public entry to the mine – features designed to limit the spread of White Nose Syndrome by humans and prevent disturbances of the hibernation area.

In October, FLT staff accompanied a team from the Massachusetts Division of Fisheries and Wildlife to install two temperature/humidity sensors in the mine. These sensors will record data on the climate conditions of the mine, helping FLT to ensure it remains a healthy habitat for the bats who overwinter there in the future. Protecting healthy habitat is a key step in supporting the recovery of our native bat populations, as scientists work to develop tools and treatments to combat the devastating effects of WNS.

While our team was in the field before the true start of hibernation season (to minimize the impact of our activity) – we were able to spot some promising signs of life, as several roosting bats were observed. With the new temperature/humidity sensors in place, we look forward to monitoring conditions in the mine, and hope the encouraging signs of activity seen in the past few years signal a resilient, recovering bat population.