Migratory Bird Treaty Act May No Longer Prohibit Incidental Take, But Don’t Forget State Regulations

By Patricia Valcarcel, Senior Biologist

A final rule was published in the Federal Register on January 7, 2021, clearly stating there is no prohibition of incidental take (unintentional capture or killing) of birds under the federal Migratory Bird Treaty Act (MBTA). This rule is a final decision after several years of uncertainty regarding federal protections for birds covered under the MBTA.

Although federal prohibitions on incidental take have now been removed, California’s codes protecting native bird nests remain unchanged and there is no substantive change for most projects within the state. A short summary on the recent update follows, and note that it may be helpful to read WRA’s previous blogs on the MBTA (2019 and 2020) for more background.

The paragraph added to the Code of Federal Regulations describes the scope of the MBTA and explicitly states that incidental take is no longer prohibited:

The prohibitions of the Migratory Bird Treaty Act (16 U.S.C. 703) that make it unlawful at any time, by any means or in any manner, to pursue, hunt, take, capture, or kill migratory birds, or attempt to engage in any of those actions, apply only to actions directed at migratory birds, their nests, or their eggs. Injury to or mortality of migratory birds that results from, but is not the purpose of, an action (i.e., incidental taking or killing) is not prohibited by the Migratory Bird Treaty Act.

The language in the final rule is effective February 8, 2021, although lawsuits are expected to challenge this rule. The MBTA rule was promoted to split into regulations the 2017 Solicitor’s Opinion (M-37050) regarding incidental take prohibitions, or lack thereof. M-37050 was vacated in a federal district court ruling in August 2020. The court’s decision may support challenges to the rule change’s Environmental Impact Statement (EIS), as the EIS analysis has already been called into question as inadequate. At a minimum, we anticipate the lawsuits will result in a delay of the effective date.

The incoming Biden administration may attempt to rescind the new MBTA rule via the Congressional Review Act (CRA); however, recourse is limited since this is now a published final rule. Separately, the House of Representatives Natural Resources Committee has been considering new legislation, the Migratory Bird Protection Act (H.R. 5552), but it has not yet moved to the full House for a vote. H.R. 5552 would amend the MBTA to specifically prohibit incidental take or unintentional killing of migratory birds and their nests and require the U.S. Fish and Wildlife Service to regulate or permit incidental take of migratory birds. The act also defines the specific activities subject to this prohibition. If passed by the House and Senate and signed into law, the MBTA would be amended, superseding the Trump administration’s January 7, 2021 final rule.

Incidental Take

What is incidental take of birds and/or bird nests? This is a take of a bird or an active bird nest (capturing or killing birds, chicks, or eggs; or nest destruction) during an otherwise authorized activity. That is, the bird or its nest was not destroyed solely for the direct purpose of removing it, but during another authorized activity such as tree trimming or vegetation removal. To put even more clearly, vegetation removal is approved to construct a house, and in the process of removing vegetation a nest with eggs is destroyed. The nest destruction was incidental to vegetation removal. Prosecutions on incidental take of nests have typically only occurred if there was negligence or large-scale mortality. Best management practices to avoid and minimize potential for incidental take include pre-construction nesting bird surveys to detect and avoid active nests, or habitat mitigation if habitat removal may result in a significant impact such as to a rookery.

California Regulations

The California Fish and Game Code (CFGC) provides protections to native bird nests (most specifically codes 3503, 3503.5, and 3513). Per CFGC section 3503, it is unlawful to “take, possess, or needlessly destroy the nest or eggs of any bird.” There has been uncertainty on the applicability of these restrictions to incidental actions; however, the State has counseled on multiple occasions that the prohibition of incidental take applies to all sections of CFGC, including nest protection. Most recently on November 29, 2018, California Department of Fish and Wildlife (CDFW) issued an advisory statement affirming California regulations protecting bird nests including protection against incidental take.


WRA’s recommendations remain unchanged from previous years, and we remind project proponents of the following:

  • All existing permit measures, California Environmental Quality Act (CEQA) Mitigation Measures, and other requirements for various actions that stipulate nesting bird avoidance are not rendered invalid by the new federal MBTA rule. Compliance is still required under State law.
  • Measures protecting nesting birds and active nests remain standard in California. For example, permits and authorizations from CDFW, such as Streambed Alteration Agreements and Incidental Take Permits, do not rely on the MBTA for the basis of bird protection, and will continue to include such measures.
  • The most effective method of avoiding impacts to nesting birds (or even simply the perception that birds have been impacted) is to perform the removal of trees and other vegetation from September 1 through January 31. This period is outside the greater nesting bird season. If this is not feasible, pre-construction surveys by a qualified biologist and subsequent avoidance of any active nests found are strongly recommended, particularly for larger-scale actions with an associated higher likelihood of impact.
  • For projects which may result in long-term or continuing impacts to birds such as wind farms or lighting projects, WRA is available to consult on project-specific practices that can minimize impacts.

WRA biologists have a tremendous amount of experience with nesting bird avoidance and related compliance issues. If nesting bird surveys are required for your action or if you simply have questions about your obligation to avoid any impacts to birds, please contact us. For additional information specific to the final MBTA rule, contact WRA’s wildlife regulatory specialist Patricia Valcarcel.