The Migratory Bird Treaty Act (MBTA) was passed in 1918 to combat over-hunting and poaching that supplied the enormous demand for feathers to adorn women’s hats. State-level hunting laws were not working, and bird populations were being decimated. At first, the Act was based on a single, 1916 treaty between the United States and Great Britain (on behalf of Canada) to protect migratory birds. Later, similar treaties were signed with Japan, Russia, and Mexico, and protection for the birds covered in these treaties was added to the MBTA.
The Act makes it a federal crime to “take” birds or bird parts, including feathers, or to kill birds without special permission from the Secretary of the Interior. The MBTA also prohibits any person from using bait to take migratory birds, or for someone to hunt in areas they know or reasonably should know are baited. Only “native” migratory bird species are protected under the MBTA, and there are now 1,026 species covered by the Act, including common birds such as the American crow (Corvus brachyrhynchos) and 74 rare birds also on the Endangered Species list, such as the spectacled eider (Somateria fischeri.)
Almost 100 years later migratory birds still face significant dangers from humans, but not because of the demand for feathered hats. Today, the greatest threat to birds is the loss and/or degradation of habitat due to development or disturbance. Additionally, hundreds of millions of birds are killed every year by collisions with human structures, poisonings, and attacks by domestic and feral cats. Migratory birds still need legal protection. But, there is considerable debate over two important issues regarding how the MBTA should now be used to achieve that protection.
First, some courts say that if a person kills a bird then they are guilty of violating the MBTA, while other courts say that a person must know that their actions were likely to harm a bird in order to be found guilty. Second, some courts say that only hunters and poachers can be convicted under the MBTA because these are the activities that the Act was intended to control back in 1918. But, other courts broadly interpret the MBTA to criminalize any activities that harm or kill birds.
With the mixed messages from the courts over the meaning of the MBTA, individuals and companies do not know what activities might lead to criminal charges under the Act or whether they will be found guilty if they go to trial. Ironically, this could be harmful to wildlife conservation because, for example, developers may not invest in strategies to protect birds if they think the government will still file criminal charges if birds are harmed. With such uncertainty involving an important federal law like the MBTA, it would not be surprising if the Supreme Court were to agree to hear one of the MBTA cases. If the Court does not take up an MBTA case soon, then Congress may amend the Act to clarify its modern meaning.