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The Migratory Bird Treaty Act: On the Wings of an Executive Branch Reinterpretation

Animal Law

Surrounded by birds, their majesty is easily taken for granted. Evolving from dinosaurs and predating humans by more than 100 million years, birds populate every climate and ecosystem around the world. Whether diving at 200 miles per hour or precision hovering as if suspended in air, their grace and athletic prowess are arguably unmatched in the animal kingdom.

The Migratory Bird Treaty Act (MBTA),1 one of the oldest and most successful wildlife conservation laws in our country, was enacted to protect these avian acrobats. On the heels of the Lacey Act,2 the MBTA provided protections beyond just interstate transport, prohibiting the taking or killing of all migratory birds. Unlike the ill-fated passenger pigeon, the MBTA has stood the test of time, surviving without fundamental change. However, 100 years after its enactment, the MBTA finds itself at a crossroads, facing an executive branch interpretation that could fundamentally change its future. This article briefly revisits the history of the MBTA and explores two competing memoranda recently issued by the U.S. Department of Interior that come to diametrically opposing conclusions as to whether the MBTA prohibits the incidental taking of migratory birds, their eggs, and nests.

the 1900s, bird populations were under severe threat. Unrestricted hunting and the lucrative millinery industry, which used feathers and wings to embellish women’s hats, led to the demise of millions of birds. The extinction or near-extinction of multiple avian species followed, such as the heath hen, great auk, Labrador duck, Carolina parakeet, and the passenger pigeon, once the most abundant bird in North America.3 There were an estimated 5 billion passenger pigeons at the time Europeans discovered America, with early writers describing the birds in terms of countless numbers, infinite multitudes, and flights a mile wide and taking several hours to pass overhead.4 It was incomprehensible for settlers to believe that humans could impact nature in any meaningful way, much less eradicate an entire species. Nevertheless, by the turn of the 20th century, there were no remaining wild passenger pigeons.5Many other bird species suffered, too, coming to the precipice of extinction. It is estimated that during a single nine-month period, 130,000 snowy egrets, admired for their wispy pure white plumage, were killed in the U.S. for use in the London millinery market alone.6

Republican Congressman John F. Lacey of Iowa, recognizing the dire situation, introduced the Lacey Act in 1900.7 Mindful of the limitations on federal authority and as pronounced in the state ownership doctrine confirmed just four years earlier in Geer v. Connecticut, 161 U.S. 519 (1896),8 the Lacey Act was drafted strategically, and intended to augment state authority rather than supplant it. More specifically, the Lacey Act criminalized the shipment of wild animals and birds killed in violation of state law, required all interstate shipments to be clearly labeled, and removed federal restrictions on the states’ ability to regulate the sale of wildlife within their borders.9 The Lacey Act, signed into law by U.S. President William McKinley on May 25, 1900, became the first federal law protecting wildlife.10

The initial effectiveness of the Lacey Act was mixed though, with courts often referring to it in decisions rather than relying on it.11 It wasn’t until the 1910s when the Lacey Act’s ability to supplement state wildlife laws became better established,12 including its first direct interpretation in Rupert v. U.S., 181 F. 87 (8th Cir. 1910).13 In its defense, the Lacey Act was up against a formidable foe with massive profits available to successful market hunters and a general lack of enforcement.14 Congress’ response to the unsustainable killing of birds did not end with the Lacey Act. The Weeks-McLean Migratory Bird Act, intended to stop commercial market hunting and the illegal shipment of migratory birds from one state to another, was passed in 1913, but found unconstitutional shortly thereafter.15 The Convention between the United States and Great Britain for the Protection of Migratory Birds in the United States and Canada (Canada Treaty) was signed in 1916.16 The Canada Treaty adopted a uniform system of protection for certain species of birds that migrate between the U.S. and Canada.17

Most notably, the MBTA was passed in 1918, which implemented and expanded beyond the provisions of the Canada Treaty. The constitutionality of the MBTA was quickly challenged by the state of Missouri, but nevertheless upheld by the U.S. Supreme Court, which found it was a necessary and appropriate means of effectuating the Canada Treaty.18 The Court noted that the protection of birds migrating between countries requires an international agreement enforced with a congressional law, as was done with the MBTA.19 Justice Holmes writing for the majority stated that “[b]ut for the treaty and the statute, there soon might be no birds for any powers to deal with.”20 Since its passage 100 years ago, the MBTA has been amended multiple times, including for the implementation of treaties between the U.S. and Mexico, Japan, and the Soviet Union (now Russia).21
As the name implies, the MBTA protects migratory birds. Most birds are migratory by nature, wholly disrespectful of the political boundaries that humans have forged and fought over for centuries. Flying between states, nations, and even continents, birds remain on the move. The tiny Arctic tern, for example, has been recorded migrating a staggering 44,000 miles a year as it zigzags its way between Greenland and Antarctica.22 Thus, the MBTA’s protection extends to most bird species, 1,026 to be exact; from the large and carnivorous bald eagle to the ruby-throated hummingbird weighing less than one ounce.23

The MBTA states in pertinent part that unless permitted by regulation, it is unlawful at any time, by any means or in any manner, to pursue, hunt, take, capture, kill, possess, sell, purchase, ship, transport, or carry, or attempt to do the same, any migratory bird, any part, nest, or eggs thereof.24 Violations of the MBTA constitute a misdemeanor crime, or felony if done “knowingly,” and may result in confiscation of guns, traps, vehicles and other equipment, up to $15,000 in fines, and up to two years of imprisonment.25 The U.S. Department of Interior’s Fish and Wildlife Service has statutory authority to enforce the requirements of the MBTA.26

Part of the MBTA’s effectiveness over the past century lies in its broad prohibitions, imposition of criminal liability, and strict liability approach.27 Strict liability has several advantages, particularly to plaintiffs and prosecutors, including that there is generally no need to plead or prove intent, negligence, or foreseeability, which can be difficult and sometimes impossible. Rather, the mere occurrence of the act and the resulting injury itself, and proof that the defendant was responsible, is sufficient to prevail at law. Few would argue with the need to prohibit, punish, and deter the intentional killing of migratory birds, one of our nation’s most important and finite natural resources. However, many bristle at the idea of potential criminal enforcement for violations that are perhaps foreseeable, but not intentional and beyond their control. Electric companies that transmit high-voltage electricity across great distances are an example. There are more than five million miles of transmission and distribution lines across the country, any one of which is vulnerable to a bird collision or electrocution.28 Taken to an extreme, the potential for a great horned owl to fly into the path of a moving automobile at early dawn is foreseeable, but nearly impossible to prevent, which could theoretically subject the driver to criminal liability and enforcement under the MBTA.

The public is often more comfortable finding a defendant responsible when culpability can be established and the idea of liability without fault more palatable when applied to areas such as defective products, toxic chemicals, explosives, and hazardous waste.29 Even when dealing with abnormally dangerous activities though, the application still has its limits.30 Fortunately, the U.S. Fish and Wildlife Service exercises enforcement discretion. The likelihood of enforcement for accidentally stepping on a piping plover nest for example is slim. However, prosecutorial discretion can sometimes lead to inconsistent application, bias, leveraging for other unrelated purposes, and overall uncertainty for the regulated community. For those engaged in activities in which bird takes are probable and unavoidable, agency predictability is desired.

Tompkins Memo
On January 10, 2017, during the last few days of the Obama Administration, U.S. Department of Interior Solicitor Hilary Tompkins issued Solicitor’s Opinion M-37041 (Tompkins Memo) “because of the confusion caused by the varying case law.”31 The Tompkins Memo, accompanied by a new version of the U.S. Fish and Wildlife Service Manual, provided in-depth research and analysis into the international conventions the MBTA implements, text of the MBTA and legislative history, relevant caselaw, and standard practices of the U.S. Fish and Wildlife Service.
The Tompkins Memo found that although none of the bilateral conventions (Great Britain on behalf of Canada, Mexico, Japan, and Russia) specifically prohibit incidental taking, these conventions “broadly support the regulation of the taking and killing of migratory birds by any means, including by industrial or commercial activities unrelated to hunting.”32 While the legislative history of the MBTA does not expressly address incidental taking, it refers not only to overhunting as a cause of population decline, but also habitat loss, including the need to protect birds for aesthetic and practical reasons “unrelated to hunting and poaching.”33

The Tompkins Memo also noted that Congress has amended the MBTA multiple times since its original enactment. Amendments were incorporated such as moving the “at any time or in any manner” language to the beginning for clarity and also inserting “by any means” into the phrase.34 Another amendment limited felony provisions to knowing violations and with an accompanying Senate report that explained “[n]othing in this amendment is intended to alter the ‘strict liability’ standard for misdemeanor prosecutions, a standard which has been upheld in many [f]ederal court decisions.”35 Additional amendments included eliminating strict liability for hunting violations involving baiting and substituting a negligence standard instead, again with an accompanying Senate report that noted it would create only a narrow exception to the longstanding general rule of strict liability, and temporarily exempting incidental taking prohibitions for military readiness activities.36

The Tompkins Memo found that the U.S. Fish and Wildlife Service had construed the MBTA as a strict liability statute since at least 1939 and consistently interpreted it to apply to both intentional and incidental takes.37 Support for this determination included the authorization of incidental takes in appropriate circumstances that “would not be necessary if the MBTA did not apply to incidental take,” working with industry to minimize incidental takes, consistent public statements made by the U.S. Fish and Wildlife Service, and enforcement actions including outside the context of traditional hunting and poaching.38 The Tompkins Memo noted that the legislation itself requires no particular mental state for misdemeanor violations and found strong consensus among courts that Congress’ decision not to expressly require a particular mental state means it is in fact a strict liability statute.39 The Tompkins Memo, which essentially memorializes the U.S. Fish and Wildlife Service’s historical position, therefore, concluded that the MBTA’s prohibition on taking and killing of migratory birds applies broadly to any activity, including incidental taking and killing.40

Jorjani Memo
With a new administration in place, just 27 days after issuance, the Tompkins Memo was suspended pending review.41 On December 22, 2017, newly appointed U.S. Department of Interior Solicitor Daniel Jorjani issued Memorandum M-37050 (Jorjani Memo) permanently withdrawing and replacing the Tompkins Memo.42 The Jorjani Memo, expressly recognizing that its interpretation was contrary to the historical practices of the U.S. Fish and Wildlife Service, concluded after reviewing much of the same information, that the MBTA applied only to affirmative actions that have as their purpose the taking or killing of migratory birds, their nests, or eggs.43

The Jorjani Memo referred to a historical expansion of federal authority, which rested on questionable legal grounds, such as the Weeks-McLean Law of 1916, which was almost immediately deemed unconstitutional.44 When Congress lacked the authority to directly legislate on the subject, the Jorjani Memo noted, advocates of nationwide hunting regulations found another way, this time through the treaty-making power.45 Congress could follow the Canada Treaty with implementing legislation and without the constitutional concerns that torpedoed the Weeks-McLean Law, resulting in the ultimate passage of the MBTA.46

Subsequent amendments to the MBTA were made to implement new treaties that followed, such as adding the word “pursue” and extending restrictions to also include nests and eggs.47 Additional amendments were also made by Congress, unrelated to any bilateral agreements. The Jorjani Memo also points out that the phrase “incidental take” does not appear in either the MBTA or the regulations that implement it, and that court decisions are mixed with some extending the MBTA to include incidental takes and others excluding it.48 The Jorjani Memo concluded based on the text, history, and purpose of the MBTA, and “sound principles of constitutional avoidance,” the MBTA criminalizes only those “affirmative actions that have as their purpose the taking or killing of migratory birds, their nests, or their eggs.”49

The U.S. Fish and Wildlife Service followed with a guidance memo on April 11, 2018, in an attempt to clarify what constitutes a prohibited take consistent with the Jorjani Memo, including several examples.50 For example, if a state pressure washes barn swallow nests off a bridge in order to prepare the structure for painting, this would constitute an affirmative act whose purpose it was to remove the nests, and consequently a permit would be required.51However, if the intent was simply to paint the bridge and nests were accidentally destroyed incidental to that overall process, a permit would not be required.52

If a homeowner knows chimney swifts are nesting inside their chimney and lights a fire to remove them, this would be an intentional act the purpose of which is to destroy the nests in violation of the MBTA.53 However, if the homeowner lights a fire for the purpose of heating the house only, this would not violate the MBTA.54 Similarly, if a landowner wants to demolish an old barn and knows there are active nesting owls in it that will die if it is demolished, this would not be a violation because the purpose was not to take the birds, nests, or eggs, but rather simply to demolish the barn.55 The landowner’s knowledge that it was reasonably foreseeable that barn owls would be killed would not be relevant. Moreover, if a farmer applies pesticides to purposely kill something other than migratory birds, it would not be a violation of the MBTA if birds happen to die as a result.56 Even if there was general intent to kill wildlife, MBTA liability would still depend on the specific facts of the situation.57

According to the guidance memo, the Endangered Species Act, Bald and Golden Eagle Protection Act, the Natural Resources Damage Assessment Program, and some state laws and regulations are not affected by the interpretation of the Jorjani Memo.58 Furthermore, under the Comprehensive Environmental Response, Compensation and Liability Act, Oil Pollution Act, and Clean Water Act, the Department of Interior remains authorized to assess injury to natural resources caused by releases of hazardous substances and discharges of oil, which includes “any injury to migratory birds.”59 Similarly, birds should still be included in the environmental review requirements of the National Environmental Policy Act.60 Under 708 of the MBTA, nothing prevents the states from passing laws that provide further protection to migratory birds.61

Legal Challenges
On May 24, 2018, the National Audubon Society, American Bird Conservancy, Center for Biological Diversity, Defenders of Wildlife, Natural Resources Defense Council, and National Wildlife Federation filed complaints for declaratory and injunctive relief against the U.S. Department of Interior and U.S. Fish and Wildlife Service in the U.S. District Court for the Southern District of New York.62 The complaints allege, among other things, that the Jorjani Memo reverses a longstanding interpretation and implementation of the MBTA, is arbitrary and capricious, violates the procedural requirements of the Administrative Procedures Act, and fails to comply with the National Environmental Policy Act.63

The MBTA was enacted 100 years ago to implement the provisions of the Canada Treaty and curb the widespread and unrestricted killing and hunting of migratory birds. The original law extended protections to game and non-game birds alike, and without reference to any requisite mental state. The MBTA has been amended several times since then, mostly to implement the provisions of new bilateral agreements or to further strengthen its protections. Even those amendments that added new mens rea standards or exempted incidental take prohibitions for specific activities may be viewed, through negative implication, as further solidifying its reach.

The U.S. Fish and Wildlife Service and many courts have interpreted the law to impose misdemeanor criminal liability without regard to fault, and for actions that either intentionally or incidentally kill or injure migratory birds, their nests, or eggs. Whether this historical interpretation was an overreach as suggested by the Jorjani Memo will be left for the courts or Congress to decide. What is known, however, is that a decision that provides clarity and protection, both to migratory birds and industry, and that is not subject to the varying interpretations of new administrations, is needed. In Florida alone, there are multiple imperiled bird species including the Everglades snail kite, scrub jay, and white ibis just to name a few.64 While much has been done to protect birds in the U.S. and across the world, more is still needed.

1 16 U.S.C. 703-712.

2 16 U.S.C. 3371-3378.

3 Mallory Henderson, Unlikely Headfellows: Reflecting on Millinery History and Migratory Bird Conservation, North Carolina Wildlife Resources Commission (May 18, 2018),

4 National Museum of Natural History in Cooperation with Public Inquiry Services, The Passenger Pigeon (Mar. 2001),

5 Id. (the last surviving passenger pigeon, “Martha,” died at the Cincinnati Zoo on Sept. 1, 1914).

6 William Souder, How Two Women Ended the Deadly Feather Trade, Smithsonian Magazine (Mar. 2013), available at

7 16 U.S.C. 3371-3378.

8 The state ownership doctrine was subsequently rejected in Hughes v. Oklahoma, 441 U.S. 322 (1979).

9 Robert S. Anderson, The Lacey Act: America’s Premier Weapon in the Fight against Unlawful Wildlife Trafficking, 16 Pub. Land L. Rev. 27,36 (1995).

10 U.S. Fish and Wildlife Services, International Affairs, The Lacey Act,

11 Anderson, The Lacey Act, 16 Pub. Land L. Rev. at 41.

12 Id. at 43.

13 Id.

14 U.S. Fish and Wildlife Service Migratory Bird Program, Other Relevant Laws,

15 Id.

16 Digest of Federal Resource Laws of Interest to the U.S. Fish and Wildlife Service,

17 Id.

18 Missouri v. Holland, 252 U.S. 416 (1920).

19 Id. at 432.

20 Id. at 435.

21 Digest of Federal Resource Lawsat 1.

22 Mason Inman, World’s Longest Migration Found — 2X Longer than Thought, National Geographic News (Jan. 12, 2010), available at

23 U.S. Fish and Wildlife Service, Migratory Bird Treaty Act Protected Species (10.13 List),

24 MBTA 703(a).

25 MBTA 707.

26 MBTA 706; see also U.S. Fish and Wildlife Services, Migratory Bird Treaty Act, available at

27 Since the 1986 amendments, strict liability applies only to misdemeanors, with knowing violations required for felony convictions.

28 Jennifer Weeks, U.S. Electrical Grid Undergoes Massive Transition to Connect to Renewables, Scientific American (Apr. 28, 2010), available at

29 Charles E. Cantu, Distinguishing the Concept of Strict Liability for Ultra-hazardous Activities from Strict Products Liability Under Section 402A of the Restatement (Second) of Torts: Two Parallel Lines of Reasoning That Should Never Meet, Akron Law Rev. 35-36(July 2015).

30 Id.

31 Incidental Take Prohibited Under the Migratory Bird Treaty Act, Memorandum M-37041 from U.S. Department of Interior Solicitor Hilary C. Tompkins 1-2 (Jan. 10, 2017).

32 Id. at 2, 4.

33 Id. at 6.

34 Id. (amendment added to now 703(a)).

35 Id. at 7.

36 Id. at 7-8.

37 Id. at 12.

38 Id. at 12-13.

39 Id. at 5, 23.

40 Id. at 2, 30.

41 The Migratory Bird Treaty Act Does Not Prohibit Incidental Take, Memorandum M-37050 from Department of Interior Solicitor Daniel H. Jorjani 1 (Dec. 22, 2017).

42 Id. at 1.

43 Id. at 2.

44 Id. at 4.

45 U.S. Const. art II, §2, cl. 2.

46 Jorjani Memo at 4.

47 Id. at 8.

48 Id. at 12, 14-17.

49 Id. at 18.

50 Guidance on the Recent M-Opinion Affecting the Migratory Bird Treaty Act, Memorandum from Principal Deputy Director, U.S. Fish and Wildlife Service (Apr. 11, 2018).

51 Id. at Attachment, FAQ 1(a).

52 Id.

53 Id. at Attachment, FAQ 1(b).

54 Id.

55 Id. at Attachment, FAQ 1(c).

56 Id.

57 Id.

58 Id. at Attachment, FAQ 5.

59 Id.

60 Id. at 1.

61 See, e.g., California Assembly Bill 2627 seeks to continue protections for migratory birds in light of the Department of Interior’s reinterpretation while providing affected
industries with clearer pathway to compliance.

62 Nat’l Audubon Soc’y et al. v. U.S. Dep’t of the Interior et al., No. 1:18-cv-4601 (S.D.N.Y. May 24, 2018); Nat. Res. Defense Council et al. v. U.S. Dep’t of the Interior et al., No. 1:18-cv-4596 (S.D.N.Y. May 24, 2018).

63 Id.

64 Florida Fish and Wildlife Conservation Commission, Imperiled Bird Species,

Photo of John K. PowellJOHN K. POWELL, J.D., P.E., is the director of the City of Tallahassee’s Environmental Regulatory Services and Facilities Department and an adjunct instructor at the FSU-FAMU College of Engineering. He received his B.S. in engineering and J.D. from the University of Florida. Powell serves on the executive council and as treasurer of The Florida Bar Animal Law Section.

This column is submitted on behalf of the Animal Law Section, Margaret Rose Hoyt, chair, and Ralph A. DeMeo, editor.

Animal Law