Since the discovery of a 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 here on the island. Because this species is at a 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 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 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 white-nose syndrome quickly burn through the fat reserves they built up throughout the fall and essentially starve to death by the time they should emerge in the spring. Additionally, the fungus can cause damage to the wing membranes, making them unable to fly if they do survive the winter. Where northern long-eared bats used to be one of the most common bat species, researchers are now reporting 90-99% population declines.
So far, the population of Northern long-eared bats on Nantucket appear to be healthy. All the bats that we have captured here have shown no symptoms of disease and only one swab returned a positive for the presence of Pd at a very low level, and that bat was asymptomatic. This indicates that Nantucket bats are certainly exposed to Pd but, for some unknown reason, do not seem to be succumbing to the disease.
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 and other researchers from SUNY at Albany to conduct a much more extensive acoustic survey of the island. This will help us pinpoint 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. 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 pine forests.
Perhaps one of the most important aspects of our work right now is locating where these bats are hibernating. This species traditionally hibernates in caves and mines, and Nantucket does not have either of these structures. The only known hibernaculum here has been in a mud-floored, cinder block crawl space under an old cape-style house. At this site, we found bats tucked inside the cinder blocks as well as in between sistered floor joists. We were able to find this one hibernaculum by attaching a radio transmitter to a bat and following it in the late fall just before it entered hibernation.
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.