For its last “Evening at the Hook” lecture for 2017, Prime Hook National Wildlife Refuge (NWR) invited Holly Niederriter, Wildlife Biologist for Delaware Natural Resources and Environmental Control, and Katelyn Rembecki, Research Assistant, to talk about Delaware bats on October 12, 2017. In addition to dispelling some myths about bats, Ms. Niederriter described the biology and status of bats and their ecological role in controlling insect pests. Population abundance of all bat species in Delaware has decreased significantly over the years, though the big brown bat (a cave species that hibernates) and the red bat (a highly migratory tree bat) are more common than the silver-haired bat, hoary bat, or evening bat. Several other species are very rare in Delaware (eastern small-footed bat, tricolored bat, little brown bat, and northern long-eared bat). Two of the numerous threats faced by bats are wind energy and persecution, but the largest current threat is white-nose syndrome (a fungal disease that kills hibernating bats when their immune systems are down).
Wind energy: Migrating bats follow wind currents, and wind turbines are sited in windy areas (e.g., along mountain ridges and in the ocean); these bats seem to be attracted to wind turbines and can be killed in large numbers. Research is being conducted on how to minimize wind turbine mortality.
Persecution: People who are scared of bats or just don’t want them in their houses kill bats. Rather than killing bats, people can work with their local natural resource agency to remove bats without harming them.
White-nose syndrome: This disease kills 90-100% of bats in many hibernacula (shelters occupied during the winter by hibernating bats). To help avoid spreading white-nose syndrome, people should comply with all cave closures, avoid caves with hibernating bats, and decontaminate their shoes before and after visiting a cave.
Over 100 agencies and organizations are collaborating under one plan in an effort to learn more about bats and protect them. The U.S. Fish and Wildlife Service has funded research on white-nose syndrome. Delaware projects include biennial emergence counts (2017 was the 7th year of volunteer counts, and this research provides estimates of reproductive rates), benchmark maternity colony work, acoustic surveys, site-specific work at Fort Delaware, and a bat box program. Volunteer bat spotters use large acoustic detectors to identify and count bats. In July and August 2017, volunteers counted almost 6,000 bats going past the bat detector at Prime Hook NWR’s Turkle Pond, and about half of these were tricolored bats, one of the rarer species that has been impacted by white-nose syndrome! Future plans include the continuation of current projects, development of a conservation and management plan, a focus on finding rare species, and acoustics and follow-up forest catches.