BiodiversityWorks made significant contributions in 2025 studying the regional movements of four bat species. In cooperation with the Massachusetts Department of Conservation and Recreation (DCR), bat expert Dr. Chris Richardson, and the U.S. Fish and Wildlife Service (USFWS), we attached tiny transmitters provided by USFWS to a number of bats. If a tagged bat passes near one of the many Motus receiving towers along the eastern flyway, the tower registers the detection, creating a valuable data point for the movements of that bat.
In the spring, the team tagged five little brown bats (Myotis lucifugus) at an overwintering site in Hingham, Massachusetts, as well as four migratory silver-haired bats (Lasionycteris noctivagans) on Martha’s Vineyard. A male silver-haired bat that we tagged June 4 on Chappaquiddick “pinged” a Motus tower in Maine, close to Baxter State Park, on June 14 — a journey of about 330 miles straight-line distance. For a species that favors old growth forest, Baxter seems like the perfect place to spend the summer! USFWS is still processing the springtime data. It is likely that movements of other tagged bats will be revealed as that processing continues.
Silver-haired bat ready for a Motus tag.
Silver-haired bat fitted with a Motus tag.
Migratory bat research resumed in late summer, after a hiatus for the bat maternity season, with the tagging of four little brown bats at a Vineyard maternity colony and two more, tagged by Dr. Richardson, at an off-island colony. With luck, one or more of these tagged bats has registered on a Motus tower during the fall swarming and migration season. Dr. Richardson and Jameson Brenner, who had worked as a BiodiversityWorks wildlife technician during the 2024 field season, visited some known hibernacula sites off-island, but they did not find any of these tagged bats. With a mild fall and tag battery life of only about 30 days, we may have missed catching them at a hibernation site. But hopefully a Motus tower data point will reveal their direction of travel.
Netting a little brown bat maternity colony in late summer.
A little brown bat ready for release.
Eastern red bats are residents here on the island from late spring into the fall, but they migrate south during the colder months when insects become much less available here. We captured and tagged five red bats (Lasiurus borealis) on the Vineyard this fall; these could have been either seasonal residents that had not departed yet or transient bats on their way south. The Trustees of Reservations welcomed our research onto their properties, which feature some great bat habitat. We captured and tagged four eastern red bats at Long Point Wildlife Refuge (LPWR) and one at Wasque Reservation. LPWR seems to be a hot spot for these bats!
The first red bat we tagged at LPWR was located the next day, September 12, using a handheld receiver and antennae. We found the bat high up in the trees not far from where it was captured. Red bats roost individually in trees, blending in among the leaves. Our last detection of the bat at LPWR was on September 16. However, on the 18th, while searching for another tagged bat, we detected the red bat along Old County Road near the West Tisbury School. We searched a few days later but couldn't find the bat again. It may have been on its big journey south! At Wasque, the only Motus tower sits on top of the Wasque gatehouse. When we receive the data from USFWS, that tower may well provide a lot of localized movement data and a date of departure south for this bat.
Red bat ready for a Motus tag.
Attaching a Motus tag to a red bat at LPWR. using a skin-safe, temporary adhesive.
In September, we unexpectedly captured two endangered northern long-eared bats (Myotis septentrionalis; MYSE) and took the opportunity to deploy tags on this species. Though these bats will probably overwinter locally, we couldn't resist a chance to get some localized movement data on this elusive species. Female northerns are known to chew antennas off quickly, and the female we tagged probably did just that: we lost her signal quickly. The male, however, retained his tag for about five days. On September 12, the day after we captured and tagged the two MYSE at Long Point, we found the male on the outside of a home close to the capture site. On the 15th he had moved to a neighbor's property and was found roosting inside a fence post! We conducted an emergence count at that cavity to see if other bats would emerge, but only the male bat was seen. Both homes were occupied by bat enthusiasts who welcomed their new house guest. On the next check, however, we could not relocate the bat. He may have flown off to find a mating opportunity. Or maybe he, too, chewed off his tag antenna. We were happy to track him for at least a few days and hope to learn that his tag registered on a tower sometime this fall.
Carolyn looking to see if she can spot a tagged MYSE in its roost.
First roost site of a tagged male MYSE.
Second roost site of a tagged male MYSE.
With bat populations decimated by white-nose syndrome and exposed to threats such as mortality caused by wind turbines, reliable information is desperately needed on bat migratory routes and roost site characteristics in the maternity and migration seasons. Scientific estimates from 2023 show that land-based wind turbines in the Northeastern United States killed 57,635 bats. We have very little data on bat movements over the ocean. Thus, the work of this partnership, combining advanced technology with old-school fieldwork, is critical as the offshore wind industry develops.
