Endangered Species Law & Policy

On August 22, 2025, the United States Court of Appeals for the D.C. Circuit upheld the decision of the U.S. Fish & Wildlife Service (Service) to deny a petition to remove the southwestern willow flycatcher (Empidonax traillii extimus) from the list of species protected by the Endangered Species Act (ESA). The Service listed the southwestern willow flycatcher as an endangered species in 1995. The southwestern willow flycatcher is a small migratory bird that winters in Central and South America with a range in the United States that includes southern California, southern Nevada ...

On September 4, 2024, the Center for Biological Diversity, along with more than 20 other groups, (collectively, CBD) delivered a petition (Petition) to the U.S. Fish and Wildlife Service (Service) in which CBD requested the Service promulgate regulations establishing a process, set of criteria, and other requirements for permitting “take” of migratory birds as a result of colliding with buildings. Specifically, the Petition requests the Service require permits for new construction of buildings with glass facades or other features that would foreseeably lead to ...

On May 7, 2021, the U.S. Fish and Wildlife Service (USFWS), as many anticipated, published a proposed rule to revoke a Trump Administration rule impacting the scope of the Migratory Bird Treaty Act (MBTA).  The Trump Administration rule was finalized on January 7, 2021 and became effective March 8, 2021.  It clarified that the MBTA’s prohibition against the take of migratory birds did not extend to death or injury of migratory birds that results from, but is not the purpose of, an action (also known as incidental take).  Prior to the Trump Administration Rule, USFWS had, for decades ...

Recently, the Department of the Interior released a pre-publication version of a Federal Register notice delaying the effective date of the Migratory Bird Treaty Act (MBTA) take definitional rule to March 8, 2021, and opening a 20-day public comment period, which will close March 1, 2021.  The MBTA was enacted in 1918 to implement an international convention for the protection of migratory birds in response to declines in populations of a number of species of birds resulting from widespread hunting and poaching.  The take definitional rule states in full:

“The prohibitions of the ...

On January 7, 2021, U.S. Fish and Wildlife Service (USFWS) published a final rule limiting the scope of the Migratory Bird Treaty Act (MBTA)’s prohibition on the take of migratory birds. The new rule excludes incidental take, meaning bird mortality that results from an action but is not the purpose of that action. 

This rule is the culmination of Trump Administration efforts that began shortly after it took office to reverse prior agency policy and limit the scope of the MBTA. The rule does not take effect until February 6, 2021 and so may be suspended by the incoming Biden ...

On December 22, 2017 the Department of the Interior (DOI) Solicitor's Office issued its revised interpretation of the Migratory Bird Treaty Act’s (MBTA) prohibition on the take of migratory bird species.  Official opinions from the DOI Solicitor’s Office are known as M Opinions and carry substantial weight in how DOI applies and enforces the various wildlife laws under its purview.  In January 2017, the prior DOI Solicitor issued Opinion M-37041, Incidental Take Prohibited Under Migratory Bird Treaty Act, which concluded that the MBTA’s broad prohibition on taking and ...