Two conservation groups sued the Trump administration over its interpretation of the Migratory Bird Treaty Act (MBTA), a law that onshore oil and natural gas producers try to follow as they look to minimize the impact their operations have on several bird species, including the greater sage grouse and the lesser prairie chicken.

MBTA stipulates, among other things, that it is illegal to "pursue, hunt, take, capture, kill, attempt to take, [or] capture or kill" migratory birds "by any means whatever...or in any manner," unless permitted by regulations. Last December, Department of Interior’s (DOI) Daniel Jorjani, principal deputy solicitor, issued an opinion that said MBTA's prohibitions only apply to "direct and affirmative purposeful actions that reduce migratory birds, their eggs, or their nests, by killing or capturing, to human control."

However, on Thursday, the National Resources Defense Council Inc. (NRDC) and the National Wildlife Federation (NWF) filed a lawsuit regarding the opinion in U.S. District Court for the Southern District of New York, NRDC et al v. DOI et al, No. 1:18-cv-4596. Jorjani and the DOI's Fish and Wildlife Service (FWS) are also named as defendants.

"The Jorjani opinion is unlawful because it misconstrues the MBTA," the NRDC and NWF said in their complaint. "Its interpretation stripping the agencies of authority to regulate incidental take violates MBTA's plain text, which broadly encompasses the killing of migratory birds 'by any means or in any manner.'" The opinion "allows companies to knowingly and recklessly kill birds, undermining reasonable efforts to prevent unnecessary deaths. And it eliminates MBTA's application in egregious cases of mass slaughter of migratory birds, such as large-scale oil spills."

MBTA was enacted in 1918, following a 1916 agreement between the United States and Great Britain, acting on Canada's behalf, to protect the birds. Amendments were tacked on to MBTA following separate treaties between the United States and Mexico (in 1936), Japan (1974) and the Soviet Union (1978), now Russia.

In 2015, FWS announced plans to prepare a programmatic environmental impact statement (PEIS) on MBTA. Specifically, the PEIS was intended to strengthen MBTA by addressing threats to birds posed by natural gas flares and uncovered waste oil pits, as well as unprotected power lines and communications towers.