10/03/2026
Say hello to the northern long-eared bat! Another of the many bat species that can be found in Wisconsin. Northern long-eared bats are usually brown to light brown and weigh between 5-8 grams. They usually measure at around 3 inches from head to toe, and have a wingspan of around 9-10 eir ears are longer than other similar sized bats, reaching past its nose when pushed forward. They also have longer tails and broader wings than related species, allowing them to be more maneuverable in flight.
After hibernation, reproductive females roost alone or with a few other females under tree bark and in tree crevices, and rarely in man -made structures. Sometimes, the females will use roost networks, which is a group of different resting sites that they will use and share with other female bats in a colony. Males and non-reproductive females roost singly in tree crevices of hardwood trees. In winter, the northern long-eared bat hibernates in caves and abandoned mines where temperatures remain constant. They tend to hibernate singly, unlike little brown bats which will hibernate in clusters.
Major threats against the northern long-eared bat include habitat loss, human disturbance, and white nose syndrome. Populations are estimated to have declined by at least 90% in the last ten years due to white-nose syndrome alone. The bat was listed as Threatened under the U.S. Endangered Species Act in 2015 and up-listed to “Endangered” in November 2022.
Bats are an important part of our ecosystem. They pollinate plants, keep our pest and insect populations down, serve as prey to other animals, and disperse seeds to help maintain plants and forests.
