Construction, Confusion, and Collision: Avian Interactions With the Built Environment

by John K. Powell and Delaney S. Powell  Vol. 98, No. 5   September/October 2024

The planet’s population is steadily increasing, each year adding 75 million along with a proportional increase in goods and services such as food, water, and shelter. With a finite supply of natural resources and space, the environment often takes a hit, and in ways that are generally predictable. However, one common amenity has a passive yet devastating effect on a particular group of animal species, which is not well known. Each year, an estimated one billion birds die from collisions with buildings.^[1] However, such impacts can be largely mitigated through a multi-pronged approach that calms the volatility and clarifies the reach of existing laws like the Migratory Bird Treaty Act (MBTA),^[2] offers alternative legal approaches that add flexibility, and enacts new legislation at the state and local levels mandating relatively simple building redesign.

Introduction

Our affinity for birds is understandable. The hummingbird flaps its wings 5,000 times per minute while the remainder of its body waits motionless.^[3] The bar-tailed godwit flies more than 8,000 miles without stopping even once for food or rest.^[4] The peregrine falcon dives at 240 mph, the fastest moving animal on the planet.^[5] Birds like the pelican and osprey have conquered both air and water, plunging deep under the turbulent waters of the Atlantic to catch shiny and otherwise unreachable prey.

However, man-made structures that jut out of the ground can mimic a bird’s natural habitat and become essentially invisible, fatally interrupting millions of years of instinctual and evolutionary flight patterns. Instead of soaring effortlessly into what appears to be open sky or forest, birds are abruptly met with hard and unforgiving glass. Most who work in office buildings have witnessed or heard the impacts. Birds can suffer internal bleeding, concussions, and damage to bones, beaks, wings, and eyes.^[6] While many are killed instantly, dropping to the base of the offending building, others might manage to fly off only to die later.^[7] In their injured and vulnerable state, they are also more likely to succumb to predators.^[8] It is estimated that more than half of the birds that collide with buildings die as a result.^[9]

The impacts with automobiles, radio towers, and windmills, and bird interactions with poisons and oil pits do not compare to impacts with manmade buildings.^[10] Aside from habitat destruction and electrocution, the only greater threat comes from our feline friends;^[11] outdoor cats kill an estimated 2.4 billion birds annually.^[12]

Sustainable Development and Voluntary Initiatives

With the addition of billions of dollars of federal and state infrastructure-related funds to the economy, the ongoing efforts to clear lagging backlogs experienced during the COVID-19 shutdown, and the shortage of affordable housing, the number of new building construction projects remains steady, as does the tension between conservation and development. This conflict is hardly new. The 1992 United Nations Conference on Environment and Development (UNCED) was one of the most widely-attended and successful international conferences. However, the UNCED, which among other accomplishments presented the landmark Framework Convention on Biological Diversity that prescribes steps for the protection and sustainable use of the world’s plant and animal species and also introduced the concept of sustainable development, nearly did not happen because of opposing interests of participating countries.^[13] Some countries prioritized economic development and poverty alleviation while others focused on environmental protection and conservation. It is not difficult to recognize why developing countries might be resistant to measures curtailing growth or to spending already limited resources on species conservation. Many countries are struggling just to obtain clean water, ample food, and basic health care, or are plagued by violent crime and war. It is also not difficult to recognize how similar scenarios might play out at the state and local levels here in the U.S.

When the environment takes a back seat to survival or other more pressing priorities, it is no surprise that the compliance rate with aspirational goals, such as species and habitat conservation, leaves a lot to be desired. However, with the concept of sustainable development, the developed-verses-developing dilemma was believed to be resolved and these two goals were viewed as mutually reinforcing rather than exclusive. A core tenet of sustainable development is that not all development is good. Instead, growth must be planned and well managed. Careful consideration of location, density, transportation, energy usage, waste management, and impacts to flora and fauna, among other critical factors, are essential to achieving development that promotes economic well-being while protecting natural resources. Unfortunately, despite strong international commitments and best intentions by participating states, and as time has shown, these sustainable development considerations must not be purely aspirational but legally mandated to ensure implementation and success. This is true not only at the international level, but at all levels.

Meanwhile, bird populations continue to decline with 89 species protected under the MBTA listed as threatened or endangered under the Endangered Species Act and an additional 342 listed as birds of conservation concern.^[14] Biodiversity is not only an aesthetic benefit, it is a necessary part of a complex and interconnected web that benefits all. Biodiversity is integral to a healthy and resilient ecosystem and part of our culture and identity. It also bolsters the economy in ways that are not possible to quantify. Birds provide essential services to support mankind, like dispersing seeds to burned areas to aid forest regeneration, pollinating crops, and controlling insect populations that threaten farmland and spread disease.^[15] Akin to Einstein’s “spooky action at a distance,” we theorize that everything is linked and even actions seemingly small and far removed in time and space are actually quite close and impactful.^[16]

Existing Legal Requirements

Our efforts to afford legal protection to wildlife including birds are long standing. Legal juggernauts like the Lacey Act^[17] and MBTA have been in place for more than a century, helping lay the foundation for additional future protections. The Lacey Act is arguably the single most effective law to protect wildlife in the U.S.^[18] Passed in 1900, it is the country’s first federal wildlife protection law.^[19] The Lacey Act has been amended and expanded several times, and imposes both civil and criminal penalties for the take, possession, transport, or sale of wildlife that has been taken in violation of any law.^[20] It is one of the broadest and most comprehensive federal conservation laws that agencies can use to protect wildlife.^[21] In addition to its own inherent protections, the Lacey Act strengthens the ability to enforce other important wildlife laws such as the Endangered Species Act,^[22] the Marine Mammal Protection Act,^[23] and the MBTA.^[24] It also enhances our ability to enforce the provisions of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.^[25] What it does not do, however, is prohibit or address bird collisions with structures such as office buildings or condominiums.

Building on the Lacey Act, the MBTA of 1918 was enacted to ensure the sustainability of populations of all protected migratory bird species by prohibiting taking, killing, capturing, selling, trading, and transporting, without prior authorization from the U.S. Fish and Wildlife Service (FWS).^[26] It is our nation’s most important bird conservation law and today it implements four international conservation treaties the U.S. entered into with Canada (1916), Mexico (1936), Japan (1972), and Russia (1976).^[27] The MBTA was amended in 2004 to clarify that its protection only extended to migratory bird species that are native to the U.S. or its territories, and that a native migratory bird species is one that is present as a result of natural biological or ecological processes.^[28] The MBTA requires the U.S. Fish and Wildlife Service publish a list of all nonnative, human-introduced bird species to which the MBTA does not apply.^[29] This list was last published in 2020.^[30]

Confusion and Controversy

Unfortunately, and despite being more than a century old, the MBTA has had more than its fair share of confusion and controversy, particularly in the last decade. This strict liability statute is often interpreted and enforced quite leniently, and perhaps understandably so. The threat of being held criminally liable for a bird take where reasonable precautions have been taken, when an essential service like electricity is being provided, or where there is no intent to cause harm, can sound extreme. Competing memoranda clarifying or, depending on who you ask, reinterpreting its reach have been issued from the most recent three presidential administrations.

First, on January 10, 2017, during the waning days of the Obama Administration, then U.S. Department of Interior Solicitor Hilary Tompkins issued Solicitor’s Opinion M-37041 (Tompkins memo).^[31] The Tompkins memo, which was in response to varying interpretations by the courts and enforcement by the Department of Interior itself, clarified that the U.S. Fish and Wildlife Service had construed the MBTA as a strict liability statute since at least 1939, that the legislation required no particular mental state, and that it applied broadly to any activity including both the intentional and incidental taking or killing of protected bird species.^[32] With this interpretation, the incidental killing of birds due to collision with buildings, electric lines, or windmills for example would fall squarely within the MBTA’s prohibitions.

Next, with the Trump Administration in place, the Tomkins memo was quickly suspended pending review. On December 22, 2017, the newly appointed U.S. Department of Interior Solicitor Daniel Jorjani issued Memorandum M-37050 (Jorjani memo) permanently withdrawing and replacing the Tompkins memo.^[33] The Jorjani memo stated that the threat of strict, criminal liability under the MBTA hung like “the sword of Damocles” over otherwise lawful and productive activities.^[34] After reviewing much of the same information as its predecessor, the Jorjani memo concluded that the MBTA only applied to “affirmative actions that have as their purpose the taking or killing of migratory birds, their nests, or their eggs.”^[35] Under the Jorjani memo, one could assume that if a 10-story glass office building was designed and constructed for the purpose of housing employees, and birds were thereafter killed due to collisions with its highly reflective or transparent windows, this would not be deemed a violation since the purpose was not to take the birds but rather to simply construct a building. Although the U.S. District Court for the Southern District of New York vacated the Jorjani interpretation on August 11, 2020, finding it was contrary to the plain language of the MBTA,^[36] the U.S. FWS published a final rule on January 7, 2021, codifying the Jorjani interpretation that the MBTA only applies to purposeful takes.^[37]

Most recently, the Biden Administration weighed in on the debate. On March 8, 2021, U.S. Department of Interior Deputy Solicitor General Robert Anderson issued Memorandum M-37605 (Anderson memo), which permanently withdrew the Jorjani memo (which previously withdrew the Tomkins memo).^[38] The Anderson memo cited the holding in Natural Resources Defense Council v. U.S. Dep’t of the Interior, 478 F. Supp. 3d 469 (S.D.N.Y. 2020), which concluded that the MBTA makes it unlawful to “at any time or in any manner” kill any migratory bird.^[39] The Anderson memo also drew support from Canada’s concerns that the prior Jorjani memo might be inconsistent with one of the treaties underlying the MBTA, the 1916 Convention Between the U.S. and Great Britain (for Canada) for the Protection of Migratory Birds, as amended by the 1995 Protocol Amending the 1916 Convention for the Protection of Migratory Birds.^[40]

Consistent with the Anderson memo, on May 6, 2021, the U.S. FWS announced a proposed rule to formally revoke the Jorjani memo.^[41] Following through, on October 4, 2021, the U.S. FWS published an advanced notice of rulemaking to codify the current administration’s interpretation that the MBTA prohibits the incidental take of migratory birds and to develop regulations that authorize incidental takes only under prescribed conditions and with regulations that were not unduly burdensome.^[42] Also on October 4, 2021, the U.S. FWS revoked its prior January 7, 2021, final rule, which had the immediate effect of returning to implementing the MBTA as prohibiting incidental take and applying enforcement discretion, consistent with judicial precedent and prior agency practice.^[43]

With the final rule publication and notice of proposed rulemaking in place, the new permitting program was poised to take flight. However, on December 1, 2023, much to the dismay of conservation advocates, the U.S. FWS discretely announced that the rulemaking efforts were placed on hold.^[44] To date, these efforts remain on pause.

Design Alternatives

Fortunately, there are simple bird-friendly solutions available, many of which are cost effective, do not negatively affect the building’s aesthetics, or obstruct the occupant’s view of the outdoors. For example, the use of window tinting or decals can help birds see otherwise reflective windows and avoid them. Utilizing etched, fritted, or frosted glass would provide a similar result. Ultraviolet patterned glass, which is invisible to people but not to birds, can also be incorporated. Channel glass that provides flexibility in design and construction as well as a variety of unique, beautiful, and modern looks is another bird-friendly option.

From the interior, the use of window blinds or curtains have been shown to deter bird strikes. Finally, minimizing artificial lights at night either by manually turning them off at the end of the day or automatically through programmable timers or motion sensors helps too. Birds are drawn to lights, which can cause confusion and potentially collision, particularly on foggy nights or when there are low-cloud ceilings.^[45] Light management also offers the dual benefit of reducing energy costs.

These simple building modifications have proven to be highly effective. One example is the Jacob K. Javits Convention Center in New York City. Originally designed by award-wining architect I.M. Pei as a modern crystal palace with highly reflective dark glass, the facility was documented as one of the city’s greatest causes of bird collision mortality.^[46] During a 2013 renovation, nearly one-third of the Javits Center glass was replaced with stainless steel panels.^[47] The remaining glass was replaced with low reflection and patterned glass with less than half the reflectivity of the original.^[48] This conversion reduced bird deaths by 90% and improved energy consumption, while retaining the building’s aesthetic beauty and character.^[49]

Looking Ahead

The reach of the MBTA as it relates to incidental takes needs to be clarified and solidified once and for all. Birds continue to die at an alarming rate and the regulated community operates with uncertainty. However, absent federal legislation addressing the issue, which may be unrealistic, a regulatory permitting program should be developed to establish reasonable precautions to mitigate bird mortality while providing regulatory certainty. The program would be developed by the U.S. FWS and delegated to state wildlife or environmental agencies such as the Florida Fish and Wildlife Conservation Commission. Such a permitting program could apply to new commercial building construction or major exterior renovations only, thereby grandfathering in existing and unaltered buildings and minimizing potential backlash. Regulated buildings might include those that are three stories or taller, greater than 10,000 square feet in conditioned area, and that already are using or plan to use more than 50% glass or other transparent or reflective exterior cladding. Even if a building met the physical criteria for eligibility, it would be subject to the permitting program only if that building was also located in areas of documented avian use or concern.

Once a building was deemed subject to the permitting program, an analysis of local bird populations, including the potential presence of threatened or endangered species and seasonal flight and migration patterns through the subject area, would be conducted. Next, there would be an evaluation of the proposed building exterior and its potential impact on these identified birds. For example, its reflectivity, transparency, glass height, and planned use of nighttime lighting would be analyzed.

Technical feasibility would also be considered including structural integrity, storm resilience, life cycle, and energy efficiency. Finally, if the project is in an area of concern, the proposed cladding is determined to have a detrimental impact, and the use of alternative cladding is found technically feasible, then an economic evaluation including the cost to convert to bird-safe cladding including the percentage of total project cost would be conducted. Agency staff would determine if the conversion were cost prohibitive using a formula that would be developed during rulemaking. However, in many cases, there is no additional cost for these bird-safe features, particularly when incorporated early in the design and construction phase.^[50]

If it is technically or economically infeasible to convert, the permittee would then have two options. The permittee could mitigate impacts or incidental takes through the planting of trees or preservation of green space. Otherwise, in lieu of bird-safe cladding or implementation of an environmental in-kind project, the permittee could pay into to a mitigation fund which identifies and applies the money to help mitigate local avian concerns.

Since migratory and flight patterns are site specific, a one-size-fits-all approach would not be effective or equitable. What is appropriate for a building in Florida may not be for a building in Indiana, for example. Even a wooded area in North Florida may require different considerations than a coastal area in South Florida. Therefore, state and local building codes should be amended consistent with the permitting program to include a consideration of bird collisions with new or major building renovations.

Many local governments are not waiting for legal mandates, but instead are acting on their own. For example, New York City in 2019 passed legislation that requires new construction and renovation to incorporate specialty treated glass on the bottom 75 feet of buildings.^[51] Similarly, San Francisco adopted bird-friendly requirements in 2011.^[52] Portland, Oregon, also requires new buildings and major renovations to incorporate bird-safe windows and glazing.^[53] The state of Minnesota applies bird-friendly standards to new building construction and major renovation projects.^[54] Highland Park, Illinois, mandates that the city will at least consider bird-friendly design to the greatest extent practicable in the construction of new city buildings.^[55] In Florida, the University of Florida established a bird collision project with the goal to make its 2,000-acre campus safe for birds, and Florida International University has implemented fritted glass and a nighttime light management program on some if its new buildings.^[56]

Providing incentives for non-reflective or transparent glass through tax reductions, expedited permitting, or low interest rate loans that provide collateral energy efficiency benefits may increase the chance for success. Similarly, persuasion may be an appropriate and somewhat softer approach through publication of bird mortality data per building or company like what is often done with carbon emissions. Admittedly, gathering this data could prove problematic and may be grossly inaccurate thereby defeating the purpose.

Conclusion

Birds continue to die at an astounding and unnecessary rate due to collision with buildings that utilize reflective or transparent glass. Fortunately, the problem is easily addressed through use of bird-friendly cladding, which often adds little or no cost to construction, particularly when incorporated early in the design phase. However, aspirational initiatives to incorporate bird-friendly materials have proven ineffective and, therefore, a legal mandate is required. Such a mandate should provide protection to birds, flexibility in implementation, and certainty to the regulated community. The MBTA could provide that legal mandate. However, it continues to be the victim of differing political interpretations. This once strict liability statute has become strictly unreliable when it comes to legal interpretation and enforcement. Should the presidential administration flip once again this upcoming election season, the U.S. FWS will likely reverse its own October 4, 2021, revocation and reissue yet another memorandum on this very subject in less than eight years. This potential memorandum would be expected to reinterpret the MBTA’s reach to specifically exclude incidental takes, thereby denying, at least for the time being, the looming threat of the falling sword of Damocles.

This column is submitted on behalf of the Animal Law Section, Laura A. Roe, chair, Ralph A. DeMeo, editor, and Macie J. Routa, special editor.