Migratory Bird Treaty Act of 1918

The Migratory Bird Treaty Act of 1918 (MBTA), codified at 16 U.S.C. §§ 703–712 (although §709 is omitted), is a United States federal law, at first enacted in 1916 in order to implement the convention for the protection of migratory birds between the United States and Great Britain (acting on behalf of Canada). The statute makes it unlawful to pursue, hunt, take, capture, kill or sell birds listed therein ("migratory birds"). The statute does not discriminate between live or dead birds and also grants full protection to any bird parts including feathers, eggs and nests. Over 800 species are currently on the list.

Narrow exceptions to the act, known as the eagle feather law, are enacted in federal regulations (50 C.F.R. 22), which regulates the taking, possession, and transportation of bald eagles, golden eagles, and their "parts, nests, and eggs" for "scientific, educational, and depredation control purposes; for the religious purposes of American Indian tribes; and to protect other interests in a particular locality." Enrolled members of federally recognized tribes may apply for an eagle permit for use in "bona fide tribal religious ceremonies."

The Act was enacted in an era when many bird species were threatened by the commercial trade in birds and bird feathers. The Act was one of the first federal environmental laws (the Lacey Act had been enacted in 1900). The Act replaced the earlier Weeks-McLean Act (1913). Since 1918, similar conventions between the United States and four other nations have been made and incorporated into the MBTA: Mexico (1936), Japan (1972) and the Soviet Union (1976, now its successor state Russia). Some of these conventions stipulate protections not only for the birds themselves, but also for habitats and environs necessary for the birds' survival.

Constitutionally this law is of interest as it is a use of the Federal treaty making power to override the provisions of state law. The principle that the Federal government may do this was upheld in the case Missouri v. Holland.