To embed, copy and paste the code into your website or blog: On May 7, 2021, the U.S. Fish and Wildlife Service (“USFWS” or “Service”) published a proposed rule that would restore the traditional interpretation of the Migratory Bird Treaty Act (“MBTA”) as prohibiting incidental take and not just purposeful killing of migratory birds. This was a predictable step by the Biden Administration, but the proposed rule contains some revealing commentary that may signal how the USFWS will implement and enforce the MBTA after the rule is finalized. I. Political Ping-Pong For over fifty years it was widely accepted that the prohibition in the MBTA against killing migratory birds “at any time, by any means, and in any manner” applied to incidental killing, or “take” of migratory birds as well as intentional killing. Courts that had interpreted the statute generally confirmed that interpretation with a few exceptions, most notably the Fifth Circuit Court of Appeals. In the waning days of the Obama Administration, The Department of Interior’s (“DOI”) Solicitor General issued a memorandum opinion, M-37041, explicitly confirming the DOI’s long-standing interpretation that the MBTA prohibited incidental take and providing the legal basis for that interpretation. Shortly after the Trump Administration took office, the new DOI Solicitor, Daniel Jorjani, suspended M-37041, and less than a year later issued a new opinion, M-37050, reversing the DOI’s long-standing interpretation based on a completely contrary legal analysis.