JACKSON, Wyo. — The U.S. Fish and Wildlife Service (USFWS) today announced a proposal to list the tricolored bat as endangered under the Endangered Species Act (ESA).
According to the press release announcing the proposal, the species faces extinction due primarily to the range-wide impacts of white-nose syndrome, a deadly disease affecting cave-dwelling bats across the continent. The distinction would not designate critical habitat.
“White-nose syndrome is decimating hibernating bat species like the tricolored bat at unprecedented rates,” said Service Director Martha Williams. “Bats play such an important role in ensuring a healthy ecosystem. The Service is deeply committed to continuing our vital research and collaborative efforts with partners to mitigate further impacts and recover tricolored bat populations.”
The tricolored bat is found east of the Rocky Mountains in 39 U.S. states, including eastern portions of Wyoming, the District of Columbia; in four Canadian provinces from the Atlantic Coast west to the Great Lakes; and in portions of eastern Mexico, Guatemala, Honduras, Belize, and Nicaragua.
A USFWS review found that the species has declined dramatically across its range and now meets the definition of endangered under the ESA.
“White-nose syndrome has caused estimated declines of more than 90 percent in affected tricolored bat colonies and is currently present across 59 percent of the species’ range,” according to USFWS.
White-nose syndrome is caused by the growth of the fungus, Pseudogymnoascus destructans (Pd). The fungus thrives in cold, dark and damp places like caves.
In April, Wyoming Game and Fish confirmed that Pd was identified in Carbon and Platte counties within caves that serve as hibernaculum, locations where bats hibernate.
White-nose syndrome erodes the skin of hibernating bats and causes them to wake up more often than normal, which takes valuable energy. The syndrome kills bats through starvation or exposure when they leave the hibernaculum in search of food in the winter.
The U.S. Geological Survey — National Wildlife Health Center confirmed four bat species tested positive for Pd: Townsend’s big-eared bat, Western small-footed myotis, little brown myotis and western long-eared myotis. It is the first time Pd has been identified in a hibernacula in Wyoming.
USFWS estimates that bat populations contribute at least $3 billion annually to the agriculture economy due to pest control and pollination.
Tricolored bats are vulnerable to the disease during the winter, when hibernating in caves and abandoned mines and tunnels. During spring, summer, and fall, they roost primarily among leaf clusters of live or recently dead trees, emerging at dusk to hunt for insects over waterways and forest edges.
USFWS also listed other threats to tri-colored bats driven by climate change including changes in temperature and precipitation, disturbances to their roosting, foraging, winter habitats and high mortality at wind energy facilities.
The proposal follows the March 2022 announcement of a similar finding for the northern long-eared bat, which the Service recommended should be reclassified from threatened to endangered due largely to white-nose syndrome.
Endangered species are those that are in danger of extinction, while threatened species are defined as likely to become endangered in the foreseeable future.
Comments are open Sept. 14 through Nov. 14.