Efforts by the Trump administration to weaken the century-old Migratory Bird Treaty Act were blocked by a federal judge, who said the revisions produced by the Interior Department are "contrary to the plain meaning of the MBTA and therefore must be vacated."

In her 31-page ruling (attached below), U.S. District Judge Valerie Caproni of the Southern District of New York pointed to where the so-called Jorjani Opinion lacked needed substance -- "the Opinion is riddled with ambiguities made only more apparent by the incoherent guidance FWS subsequently issued." -- and was counter to the Interior Department's "prior longstanding position and enforcement practices" under the treaty.

"... the Jorjani Opinion’s interpretation runs counter to the purpose of the MBTA to protect migratory bird populations," Judge Caproni noted in her ruling released Tuesday. "Despite strong textual support for that purpose, the Opinion freezes the MBTA in time as a hunting-regulation statute, preventing it from addressing modern threats to migrating bird populations.

"... Interior has previously acknowledged that it has a 'legal responsibility under the MBTA and the treaties the Act implements to promote the conservation of migratory bird populations,'" the judge added. "Despite that acknowledged responsibility, the record shows that the Opinion substantially removes prior incentives for commercial actors to take precautions to avoid threats to migrating birds."

The judge turned to literature -- Harper Lee's To Kill A Mockingbird, specifically --  in prefacing her ruling:

It is not only a sin to kill a mockingbird, it is also a crime. That has been the letter of the law for the past century. But if the Department of the Interior has its way, many mockingbirds and other migratory birds that delight people and support ecosystems throughout the country will be killed without legal consequence.

At issue was an opinion written in 2017 by Daniel Jorjani, a deputy solicitor in the Interior Department. It held that penalties under the treaty could be applied only to intentional acts -- hunting and trapping, for instance -- that killed migratory birds. "Incidental" takings, such as the deaths of migratory birds that land on an uncovered pond of hazardous wastes, should not be penalized, the opinion stated.

"Interpreting the MBTA to criminalize incidental takings raises serious due process concerns and is contrary to the fundamental principle that ambiguity in criminal statutes must be resolved in favor of defendants," wrote Jorjani.

A coalition of national environmental groups, including the American Bird Conservancy, Center for Biological Diversity, Defenders of Wildlife, National Audubon Society, National Wildlife Federation filed lawsuits in May 2018 challenging the Department of the Interior’s move to eliminate protections for waterfowl, raptors and songbirds under the MBTA.

"... the administration should abandon the regulatory process it started to make this illegal bird-killing policy permanent,” Sarah Greenberger, Interim Chief Conservation Officer for the National Audubon Society, said in the wake of Caproni's ruling. “With the legal basis for its actions over the past year defeated the administration should expect more defeats in court if they try to lock-in their attempt to rollback the MBTA.”

At Defenders of Wildlife, officials said the MBTA's prohibition on the killing or “taking” of migratory birds "has long been understood to extend to incidental take from industrial activities—meaning unintentional but predictable and avoidable killing."

“The court’s decision is a ringing victory for conservationists who have fought to sustain the historical interpretation of the Migratory Bird Treaty Act to protect migratory birds from industrial harms," said Jamie Rappaport Clark, Defenders' president and CEO. "The Department of the Interior’s wrongheaded reinterpretation would have left the fate of more than 1,000 species of birds in the hands of industry. At a time when our nation’s migratory birds are under escalating threats, we should be creating a reasonable permit program to ensure effective conservation and compliance, rather than stripping needed protections for birds.”

This past February a collection of former Interior Department officials from both Republican and Democratic administrations dating back to the Nixon administration urged Interior Secretary David Bernhardt to reject the Jorjani Opinion.

“This is a new, contrived legal standard that creates a huge loophole in the law by allowing companies to engage in activities that routinely kill migratory birds so long as they were not intending to do so,” wrote the former officials in a letter to Bernhardt. “It is now more urgent than ever that we implement policies to conserve our vanishing bird species rather than unraveling decades of progress and crippling the law that protects them.”

The Migratory Bird Treaty Act turned 100 in 2018. It has been applied for decades by federal agencies and the courts to protect birds not just from unauthorized hunting but also from being harmed or killed by industrial operations. Migratory birds are increasingly threatened by land development, habitat loss, and the effects of climate change.

A recent study in Science claimed that nearly 3 billion birds have vanished from North America over the past 50 years.