As bat populations in North America continue to recover from white-nose syndrome, we know very little about the importance of currently used hibernacula and potential future hibernacula by little brown bats (Myotis lucifugus; MYLU) and northern long-eared bats (Myotis septentrionalis; MYSE) – two species hit the hardest by the fungus. We need more information on whether female bats at maternity colonies rely on one hibernaculum, or more than one, during the winter. Moreover, the pattern of movement between maternity colonies and hibernacula is not clear: are some hibernacula used by more maternity colonies than others? Dr. Chris Richardson’s work at MYLU maternity colonies across the state of Massachusetts shows that some maternity colonies are rebounding post white-nose syndrome at a faster rate than other colonies in the state. Is the difference in recovery rates based on the characteristics of colony and its members, or on features of the hibernacula? A bat’s entire life cycle is important to its recovery and persistence against the fungus that causes white-nose syndrome. But little is known about the critical connection between hibernation sites and maternity sites in the wake of white-nose syndrome in Massachusetts.
BiodiversityWorks, Dr. Richardson (Chris), and the Massachusetts Department of Conservation and Recreation (DCR) teamed up this month to try and bridge this gap of knowledge with a small pilot study. On April 12th researchers visited a site that hosts hibernating MYLU. Based on data from a previous visit to the site, some bats had already left; only about 20 remained. This was plenty of bats for our work, though, since we were only looking for five female MYLU. We were pretty lucky and found four females right away. Each female, still slightly in torpor and sleepy, was gently fitted with a small 0.32g Lotek Motus nano-tag between their shoulder blades. The tags, provided to us from U.S. Fish and Wildlife Service, were secured with an adhesive that is safe for the bats and will eventually wear off, letting the bat drop the tag (but hopefully not before we get some useful data!). We couldn’t find that fifth female, so we tagged one male MYLU as well. Once the tags were secure, we placed the bats back on the wall to let them sleep a little longer, and we all headed back to our corners of Massachusetts to wait for results.
The goal of this project is to make the connection between hibernation site and maternity site. Each tag can be detected by any of the many MOTUS Towers across Massachusetts (or the Northeast, if the bats were to travel that far). MOTUS towers are a valuable tool for researchers. No matter the project, species, or where you tag your animal, a tag will ping any tower it passes, letting researchers know which direction the animal is headed. Researchers use this tool to study movements and migration of bats, birds, and even butterflies. We will have hope that our bats pass by one of these towers. But even if they don’t, based on past research we have knowledge of known MYLU maternity colonies on the island and throughout the state. We will conduct regular checks at these sites for the tagged bats. Even one connection between this hibernation site and a maternity site will bridge the knowledge gap and help us develop plans for a larger project.
Over Easter weekend, Chris went out on his own hunt (but not for eggs!). He checked to see if the bats we tagged the week before had left the hibernation site. He found that only one female tagged bat remained, meaning the other four bats are on their way to…somewhere! We have not yet received any pings from MOTUS towers, but we are checking the website daily. We will also be planning to check our known MYLU maternity sites this week to see if any of the tagged bats are found. The tags will last about 28 days, so we intensively monitor our maternity sites in hopes of making at least one connection between a known hibernation site and maternity site.
