The Trump administration has proposed removing the threat of punishment to businesses that kill birds “incidentally.”

The U.S. Fish and Wildlife Service proposed a rule that redefines the scope of the Migratory Bird Treaty Act, a 1916 law created to protect birds migrating between the United States and Canada, to apply only to conduct that intentionally injures birds.

The proposal would remove all penalties for businesses and organizations that claim to have accidentally killed birds.

Proving intent may prove beyond the federal government’s capabilities, as it has stopped investigating most bird deaths and has discouraged local governments and businesses from taking any measures to protect birds, according to the New York Times.

The proposal comes as the number of birds in the U.S. and Canada has plummeted since 1970. According to researchers, the total population of birds is about 3 billion less that it was 50 years ago.

The public can submit comments on the proposal here until March 19.