Site loading image


New Approach to Migratory Bird Treaty Act Takes Flight

Diane Thomas | January 16, 2018

On December 22 the Department of the Interior issued a revised interpretation of the Migratory Bird Treaty Act’s (MBTA’s) prohibition on the taking of migratory bird species. While less restrictive than the previous reading of the law, the new approach could be short-lived due to the vagaries of politics and we caution our clients to be careful before changing the way they approach project planning and development or ongoing operations.

Enacted in 1918, the MBTA made it a crime to “pursue, hunt, take, capture, kill, attempt to take, capture or kill, possess, sell, purchase, or ship any migratory bird or any part, nest, or egg of a migratory bird unless authorized by regulation.” Cases related to this act originally applied only to incidents of hunting and poaching where there was a direct action by an individual.

However, in 1973 the passage of the Endangered Species Act (ESA) introduced the concept of “incidental take” – where wildlife is harmed while “carrying out an otherwise lawful activity.” Examples of incidental take under the ESA include bird strikes at wind farms or nest failure/abandonment due to construction noise and disturbance.

To comply with federal regulations and minimize harm to birds, companies and organizations have taken steps such as placing flashing warning lights on communication towers, marking power lines or fences with bird flight diverters, and fencing and netting waste pits.

But since the introduction of the ESA, courts have been divided on whether the “take” standard in the MBTA statute is the equivalent of the “incidental take” standard outlined in the ESA. The 2nd and 10th Circuit Courts of Appeal have agreed with the U.S. Fish and Wildlife Service (USFWS) that the MBTA is a strict liability statute, meaning it does not matter whether an entity intended to kill a bird. However, the 5th, 8th, and 9th Circuit Courts of Appeal hold that the MBTA only applies to direct, intentional actions such as hunting or poaching. As noted in the recent DOI memorandum, the text of the statute is ambiguous, so multiple interpretations can be expected.

The latest memo concludes that the scope of the MBTA is limited to “affirmative and purposeful actions, such as hunting and poaching.” However, the DOI reached the opposite conclusion in the final days of the Obama Administration by asserting that “the MBTA’s prohibitions on taking and killing migratory birds apply broadly to any activity, subject to the limits of proximate causation.” Given that two administrations have reached separate interpretations of the same law within a year of each other, operators should not consider this issue settled.

The DOI says there will be no more prosecutions for incidental take under the MBTA. Unless there is further guidance from the Supreme Court or Congress, however, it is possible that future administrations will interpret the act differently and reverse this latest decision. Therefore, TRC recommends that project developers and owners/operators err on the side of caution and continue to evaluate opportunities to minimize the need for an incidental take permit under the MBTA while simultaneously preparing to make a case that this requirement does not apply to their specific project.

TRC is actively monitoring developments regarding this DOI interpretation and related issues under the MBTA and the ESA. If you have questions, please contact our qualified biological and permitting staff.

Next Steps

TRC’s Sean Murphy, Aaftab Jain, and Kensley Greuter contributed to this blog.

Diane Thomas

Diane M. Thomas is a senior biologist and project manager with 26 years of experience with TRC. Her technical expertise spans a wide range of projects and industries throughout the western, central, southwestern and Gulf Coast regions of the United States. She specializes in avian biology and raptor nesting studies and has designed, conducted and supervised preconstruction field studies and post-construction monitoring for hundreds of projects, including wind projects in Wyoming, Colorado, Montana and Texas. She has conducted surveys for various threatened, endangered and protected wildlife and plant species; done extensive avian and wildlife monitoring studies; and performed general wildlife, vegetation, wetlands and natural resource studies. Ms. Thomas has prepared or contributed to numerous National Environmental Policy Act (NEPA) documents, including biological assessments for federally listed species protected by the Endangered Species Act (ESA).

By clicking "Accept", you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Read our Privacy Policy.