USFWS Proposes Listing of Tricolored Bat

Tricolored bat (Perimyotis subflavus)

Tricolored bat (Perimyotis subflavus)

On September 13, 2022, the U.S. Fish and Wildlife Service announced a proposal to list the tricolored bat (Perimyotis subflavus) as endangered under the Endangered Species Act (ESA). As of the time of this proposed listing, guidance and regulations have not yet changed; however, changes may be expected—as is the case for the northern long-eared bat, which will be ruled on in November.

Based on a thorough review of the species’ status, the species was found to have declined so dramatically across its range that it now meets the definition of endangered under the ESA. White-nose syndrome has caused estimated declines of more than 90% in affected tricolored bat colonies and is currently present across 59% of the species’ range. 

In the United States, the tricolored bat’s range includes Alabama, Arkansas, Colorado, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, Wisconsin, West Virginia, Wyoming, and the District of Columbia.    

During winter, tricolored bats hibernate in caves, abandoned mines, and abandoned tunnels ranging from small to large in size. In the southern U.S., tricolored bats may hibernate in road-associated culverts. During spring, summer, and fall months, they roost primarily among leaf clusters of live or recently dead deciduous hardwood trees. They also roost among Spanish moss in the south and bearded lichen in the north.   

The proposed rule to list the tricolored bat as endangered appears in the September 14, 2022, Federal Register. Public comments on the proposal may be submitted through November 14, 2022. 

Transportation projects covered under various programmatic consultations will not be impacted by the reclassification provided they are completed by the end of the year. Biologists strongly encourage mist-net surveys proposed for the 2022 summer survey season to include radiotelemetry for both species. EnviroScience bat biologists routinely conduct both acoustic and mist-net bat surveys, develop conservation and management plans, and work with clients to create conservation and avoidance measures. Our team is qualified and able to help you navigate your project through the ESA Section 7 Consultation process. We are keeping up with the latest information and are available at 800.940.4025 to answer any questions or concerns as to what this proposed reclassification may mean for your projects.


Few environmental firms in the country retain EnviroScience’s degree of scientific know-how, talent, and capability under one roof. The diverse backgrounds of our biologists, environmental engineers, scientists, and divers enable us to provide comprehensive in-house services and an integrated approach to solving environmental challenges—saving clients time, reducing costs, and ensuring high-quality results. Our client guarantee is to provide “Excellence in Any Environment” meaning no matter what we do, we will deliver on our Core Values of respect, client advocacy, quality work, accountability, teamwork, and safety. EnviroScience was created with the concept that we could solve complex problems by empowering great people. This concept still holds true today, as our scientists explore the latest in environmental legislation and regulations and incorporate the most up-to-date technology to gather and report data.

EnviroScience expertise includes but is not limited to: aquatic survey (including macroinvertebrate surveys and biological assessments); ecological restoration; ecological services (including impact assessments, invasive species control, and water quality monitoring);  emergency response; engineering and compliance services; endangered mussel surveys; laboratory and analysis; stormwater management; threatened and endangered species; and wetlands and streams (including delineation and mitigation). Further, EnviroScience is one of the few biological firms in the country that is a general member of the Association of Diving Contractors International (ADCI) and offers full-service commercial diving services.