Moving Toward Greater Protection for Bats

Buck Ray, Environmental

October 24, 2022

Olsson’s environmental consultants are providing client guidance on recent steps to afford greater federal protection for a pair of bat species that face extinction.

The U.S. Fish and Wildlife Service (USFWS) recently proposed listing the tricolored bat as endangered and upgrading the status of the northern long-eared bat from threatened to endangered under the Endangered Species Act (ESA). Combined, the ranges of the two species cover the eastern two-thirds of the United States.

USFWS has taken this action to head off what it has called a “growing extinction crisis” largely attributed to white-nose syndrome, a fungal disease that is virulent to cave-dwelling bats. In-depth biological reviews have estimated that the fungus wipes out 90-percent of individual bats when it infects a colony.


Only bats are known to be affected by white-nose syndrome, which has been broadly detected in 38 states and eight Canadian provinces. In addition to tricolored and northern long-eared bats, the negative effects of white-nosed syndrome are the leading cause of decline contributing to the listing of 15 bat species as federally endangered, threatened, or under review in the candidate or petition process for the ESA, according to the USFWS.

The fungus associated with white-nose syndrome is expected to continue its spread, which has implications well beyond reducing the overall numbers and species of bats. Bats are insect predators that are estimated to save U.S. agriculture $3.7 billion in costs related to pest control. Bats also function as pollinators and are essential for seed dispersal, which further increases the overall health and productivity of our ecosystems.

Precise timelines for final listing decisions are pending, but release of the final rule for the northern long-eared bat (Myotis septentrionalis) is anticipated in November. The draft rule for the tricolored bat (Perimyotis subflavus) was released on September 22, meaning the final rule could come out in late 2023.

Clients should be aware that a status change for these bats could affect ongoing and future project requirements and timelines. As a result, determining the presence or absence of an endangered species before project work gets underway always allows the greatest range of planning options.

For clients planning a project for this year or 2023, it is best to assume these species will be listed as endangered.

As required by law, the USFWS may halt projects that haven’t appropriately completed ESA consultation, however, service officials say they will work with stakeholders to conserve the bats while allowing economic activities to continue. For example, wind energy projects can move forward after minimizing and mitigating impacts on bats with habitat conservation plans, according to a USFWS news release.

To make collaboration as efficient as possible, natural resources planners must be able to navigate the expected changes to the ESA and assemble the right data for permit applications. Olsson’s biologists understand the studies, permits, regulations, and the consultations needed to comply with new regulations and changes to species listings.

Several of our biologists also hold government-issued recovery permits, which allow them to conduct mist net surveys for federally protected species, including bats. In addition, our biologists routinely conduct acoustic surveys, a noninvasive method that aids in identifying bats by detecting their echolocation calls in a target area.

Proper surveys and documentation of the species are necessary to help developers plan the best course of action for their projects. And they also allow stakeholders to design projects for the benefit of biodiversity.



Buck is a senior scientist in natural resources management, endangered species conservation, and environmental restoration and compliance. Reach Buck at 405.465.7245 or