Since the discovery of a robust population of Northern long-eared bats on Nantucket in 2015, the Foundation’s Science and Stewardship Department has been working hard to understand how these bats use habitat on the island. Because this species is at high risk of local extinction throughout much of the rest of the northeast, it is critically important to understand their ecology on Nantucket and to protect their habitat wherever possible.
Northern long-eared bats, as well as several other species, have been decimated by a disease called White-nose Syndrome (WNS) that is caused by an introduced fungus, Psuedogymnoascus destructans, or Pd. The fungus is spread from bat to bat while they are hibernating in caves or mines and grows on the skin of the face and wings, giving the bat the appearance of having a white nose. This fungal growth irritates the bats, raises metabolic rates and causes them to awaken and fly in during the winter when they should be deep in hibernation. Bats with WNS quickly burn through their fat reserves and essentially starve to death by the spring. Additionally, the fungus can cause severe damage to the wing membranes, making it difficult or impossible to fly. Whereas Northern long-eared bats used to be one of the most common bat species in the northeast, now bat biologists report population declines between 90-99%.
Despite dire news for the species in general, the population of Northern long-eared bats on Nantucket appears to be remaining relatively healthy and stable. So far, we have only had one confirmed death from WNS, a single bat was found dead by a homeowner in early April 2020. All the bats that we have captured on Island over the last 5 years have appeared in very good condition and extensive testing has revealed Pd presence on only one other bat. This indicates that Nantucket bats are at least occasionally exposed to Pd but, for some unknown reason, do not seem to be progressing to WNS.
The Science and Stewardship Department has been collaborating with several off-island researchers to learn more about our Nantucket bat populations. Zara Dowling, Ph.D. from UMass Amherst and Danielle O’Dell, Ecologist/Field Supervisor at the Foundation published a manuscript titled Bat Use of an Island off the Coast of Massachusetts. This paper details the results of an acoustic survey of bats on Nantucket and documents a breeding and hibernating population of Northern long-eared bats on the island.
We are also working with Samantha Hoff, PhD student at SUNY Albany, to conduct a more extensive acoustic survey of the island. This will help us determine what habitat types contain the highest levels of activity of Northern long-eared bats. Additionally, we are conducting radio telemetry studies to locate potential hibernacula and collecting genetic samples to determine how closely related Nantucket bats are to other populations in the northeastern Unites States. What we have learned so far is that Northern long-eared bats on Nantucket are found in a variety of habitats but they seem to prefer dense pitch pine forests and red maple swamps. We have found several maternity colonies in both live and dead pitch pine snags and the number of calls recorded on acoustic detectors is highest in the vicinity of pitch pine and hardwood forests.
Perhaps one of the most important aspects of our work right now is locating where these bats are hibernating. This species normally hibernates in caves and mines, however Nantucket has neither of these structures. Instead, we have radio-tracked our bats to several cinder block crawl spaces and basements with mud or dirt/sand floors. We found bats tucked inside the cinder blocks as well as in between sistered floor joists. These structures provide bats a relatively stable, cold, protected space to hibernate throughout the winter on Nantucket. Nearby acoustic detectors indicate that occasionally bats will emerge from hibernation on warmer winter evenings to hunt for winter moths and rehydrate in nearby water sources.
Our research continues to focus on determining important habitat features for these bats, documenting maternity roost trees and finding hibernacula. We believe that finding more hibernacula here will shed some light on the big question of why our bats - so far - seem to be healthy and avoiding the devastation of White-nose Syndrome.
Please call our office (508-228-2884) or email with any information you have about bats using your Nantucket property.