Certain species of birds that traverse the U.S. and Canada, including these snow geese, are protected by the Migratory Bird Act of 1918. The Supreme Court held that this treaty, and others like it, must prevail over state law, even if a federal statute concerning the same matter would be held unconstitutional.
The Migratory Bird Treaty of 1918 between the United States and Great Britain prohibited the killing of many species of birds that traversed certain parts of the United States and Canada. Such species were of great value both as a source of food and because they destroyed insects injurious to vegetation, but they were in danger of extermination through lack of protection.
The state of Missouri sought to have the treaty declared an unconstitutional interference with the rights that are reserved to the states by the TENTH AMENDMENT to the Constitution. In Missouri v. Holland, 252 U.S. 416, 40 S.Ct. 382, 64 L.Ed. 641 (1920), the Supreme Court held that a valid treaty...