Volume 38
Issue 3

The northern long-eared bat (Myotis septentrionalis) is federally listed as a threatened species under the Endangered Species Act. This bat can be found primarily throughout the eastern United States and Canada, though it is thought to range as far north as the Northwest Territories with a southern limit in Louisiana. In the winter, it hibernates in caves and abandoned mines. During the summer, it roosts mainly in trees and occasionally in man-made structures.

The WNS Impact

WNS, or White-nose Syndrome, is a debilitating disease that affects hibernating bats. Its caused by the fungus Pseudogymnoascus destructans, commonly known as Pd. Like many fungi, Pd is attracted to cold and damp places, namely caves. It grows on the skin of bats while they hibernate, often forming a white fuzz on the bats faces (hence the name). The problem with WNS is that the fungus causes bats to behave oddly. They become more active during hibernation and use up their fat stores that are necessary for winter survival. Some WNS-affected bats might also behave erratically, for example, by flying outside during the winter months, further depleting their energy. First reported during the winter of 20062007 in caves near Albany, New York, Pd quickly spread to other roosts and has been found in 33 other U.S. states and Canadian provinces.

Unfortunately, M. septentrionalis is highly susceptible to Pd infection. Studies from scientists (Langwig et al., 2016; Frick et al., 2017) indicate nearly 100% of individuals become infected when Pd invades a hibernacula. These individuals also carry the highest Pd loads, which can be devastating for the health and viability of entire colonies.

Dr. Fricks studies in 2015 indicated that the northern long-eared bat suffers high mortality rates from WNS, and 69% of the sites affected by the disease result in complete extirpation (removal) of the species.

Dr. Fricks research further suggests the species is slowly disappearing from most of its historical range. There may be some hope: ongoing research from Samantha Hoff at the University of Albany suggests some persistent populations of the species remain along the Northeast Coast.

Additional concerns for this species are the same as for many others:

  • Degradation of foraging areas that deplete available insect prey
  • Impacts from climate change

BCIs Ongoing Efforts

BCI is actively involved with identifying treatments to possibly eliminate or reduce the effects of WNS as well as funding research to identify anti-Pd agents that can reduce transmission and mortality rates of WNS. Efforts include:

  • Investigating the effectiveness of chitosan (a biological compound derived from shellfish) as a treatment against Pd, in collaboration with researchers Maarten VonHoff from the University of Michigan and Timothy Carter from Ball State University.
  • Studying the effects of ultraviolet-C light and polyethylene-glycol to reduce the environmental reservoir of Pd found in hibernacula. This work is ongoing with the help of researchers Craig Willis and Alyssa Stulberg at University of Winnipeg, Barrie Overton at Lock Haven University, Jeff Foster and Katy Parise at Northern Arizona University, and federal biologist Dan Lindner at the United States Forest Service.
  • Exploring the creation of artificial prey patches of insect availability outside of hibernacula in order to help bats fatten up more substantially and improve survival odds during winter. This ongoing study is being conducted in collaboration with Craig Willis and Yvonne Dzal at the University of Winnipeg.

The primary threat to the northern long-eared bat is difficult to combat. Diseases like WNS pose additional challenges beyond habitat loss or human encroachment. WNS is a debilitating condition caused by the Pd fungus, which spreads easily between colonies and quickly decimates entire affected populations. BCI is working closely with agencies such as the USGS North American Bat Monitoring program to improve the knowledge base regarding WNS and affected bats. Its pulling together long-term hibernacula surveys of bats across the U.S. and Canada to better gauge the impact of WNS.