Building Safer Cities for Birds: A Q&A with Viveca Morris and Meredith Barges

bird imprint on glass
An estimated 1 billion birds per year are killed by building collisions in the United States alone.

Building Safer Cities for Birds: How Cities Are Leading the Way on Bird-Friendly Building Policy, a new report published by the Law, Ethics and Animals Program at Yale Law School (LEAP) and the American Bird Conservancy, considers how public policies can accelerate the adoption of bird-friendly buildings at scale in the United States. Building collisions are among the leading causes of massive bird population declines, with up to 1 billion birds killed by building collisions every year in the United States. In the absence of federal action to reduce collisions at greater scale, a growing group of U.S. cities and counties have emerged over the past two decades as leaders in advancing bird-friendly building design. At least 20 U.S. cities and municipalities have enacted bird-friendly building policies since 2008. The authors of the report, Viveca Morris, LEAP Executive Director and Research Scholar, and Meredith Barges DIV ’23, policy researcher and co-chair of Lights Out Connecticut talked about their findings.

You just published Building Safer Cities for Birds: How Cities are Leading the Way on Bird-Safe Building Policies. What led you to write this report now? 

Viveca Morris: More and more U.S. cities and states are adopting bird-friendly building rules, with a major uptick in in the last five years. Just this summer, Washington D.C., the state of Maryland, and the state of Maine passed laws to protect birds in the built environment. The laws vary considerably in scope and content, and as we discovered in our research, cities and counties often model their laws on other municipal laws, so there was a real need among policy makers and bird advocates for a report like ours that analyzes and assesses existing bird-friendly building laws and sets out best practices. Our hope is that this report will help local governments to pass better laws. The goal of our project is to protect birds by accelerating the adoption of robust bird-friendly building policies, so we are offering information and tools that people need to pass robust laws. 

Meredith Barges: The growing movement of bird-friendly building laws has been spurred by the heartbreaking images of the carnage that glassy buildings cause for birds, especially for migratory songbirds. It’s estimated that 1 billion birds are killed by building collisions per year in the United States alone. That’s a staggering number. At the same time, there’s increasing awareness that simple, effective, and affordable prevention strategies are available to prevent building collisions. New technologies and a rating system to measure the threat of different materials for birds created by American Bird Conservancy over the last 13 years have made it possible to set standards for building construction and design to benefit birds. We should remember that cities and towns have been significantly altered from the woodlands and coastal areas that birds evolved to inhabit, especially now with the introduction of all-glass buildings and curtain-walls and excessive nighttime artificial lighting that pose serious threats to bird population behaviors and local ecosystems. So, we are at a moment in time when the urgent need for better protections for birds can be met by effective solutions and comprehensive policy.

What are some of the key takeaways in your report?

Morris: It’s clear that many local governments in the United States are significantly advancing the adoption of bird-friendly building design through policymaking, at little or no additional cost to these jurisdictions. We also learned that the passage of local bird-friendly building laws, especially in New York City and San Francisco, has created increased demand for bird-friendly glass, helping to spur industry and innovation.

Barges: Another finding was that local data in some cases helped to show the toll of building collisions on bird populations and justify the need for regulations — as in New York City and Madison. However, the landmark 2019 Science article “Declines in North American Avian Fauna” showing staggering drops in bird populations across North America since the 1970s was often enough to convince elected officials of the need to act on behalf of birds. So, it became clear that while local data can help make the case, it’s not necessary to adopt comprehensive legislation. In short, we can uncouple the need for local data from justification for local policies as we work to pass better laws.

Morris: And we should underscore that in all of the contexts we studied, proposed bird-friendly building policies enjoyed wide popular support. Birds are a very special type of animal that many people feel a close connection to. And so the desire to want to save birds, especially commonly recognized and beloved species like the Black-Capped Chickadee and Downy Woodpecker, from deadly building collisions was a strong impetus for passing laws, along with well-organized advocacy campaigns organized by local conservation groups, such as NYC Audubon and the experts at American Bird Conservancy, Christine Sheppard, Building Collisions Program Director, and Bryan Lenz, Bird Cities America Director. They played roles in helping to improve many of the draft laws, and so their contributions to our report were invaluable. 

Your report includes case studies on policies that have been at the forefront of the bird-friendly building movement. As you explained, the design and comprehensiveness of these city and counties rules vary significantly. Which city has the most comprehensive policy to date? 

Morris: Our report includes case studies on policies in five different jurisdictions: New York City, Arlington [Virginia], Cupertino [California], Madison [Wisconsin], and San Francisco. These are widely divergent contexts, and, as we found, very different policies and standards. And while none of the laws we studied are perfect, we did find that some laws were better and more comprehensive than others at protecting birds. In particular, of our group of policies, New York City's Local Law 15 of 2020 stands out because it has the least number of exceptions for different types of buildings and has the highest height mitigation threshold for building exteriors (up to 75 feet above grade). New York City’s example has shown that passing robust legislation that can save birds from deadly window collisions is possible in a major and diverse metropolis.

Barges: We also chose to look not just at policies designed to protect birds through incentive programs. We believe that this is another way that cities and towns can accelerate the adoption of effective bird-friendly building standards — especially in jurisdictions where there may not be the local authority or consensus to pass a mandatory building or zoning standard. One of our case studies examines Arlington County’s Green Building Density Incentive Program — an innovative approach to promoting sustainable building practices in the county by requiring that buildings seeking greater density for new construction are approved under the provision that they must follow certain sustainability practices, including bird-safe design. The county ties its standard to U.S. Green Building Council’s LEED Rating System

Morris: Interestingly, while the county passed a voluntary density bonus for bird-friendly rules in 2014, it upgraded its rule in 2020 to be mandatory. So now all developers of new construction projects in Arlington that participate in the program must incorporate bird-friendly building materials and design. It shows the value of revisiting bird-friendly building laws to improve on them as needs and technologies change and scientific understanding advances. And by the measurement of comprehensiveness, still much more could be done for birds in Arlington County, considering that it has the lowest height threshold of any of the five laws that we examined at only the first 36 feet above grade.

What do you see as the future of bird-friendly building policies in the United States and internationally?

Barges: We were just talking about Arlington County’s Green Building Density Incentive Program — and that policy points us to the natural and inherent link between bird-friendly building practice and green building practice as allied efforts to build in ways that put fewer pressures on the environment. As Michael Mesure, of FLAP Canada, puts it, “A building isn't green until it’s bird friendly. ” For me, bird-friendly building is part of our growing awareness of how our actions can impact the environment and other species significantly. It helps us to express and fulfill our need to live in ways that are more respectful of and connected to nature. So, there should really be an awareness and deliberate linkage in practice between green building and bird-friendly building as a basic starting point in sustainability.

Morris: Many green building policy tools have yet to be attempted with bird-friendly building, such as incentives like expedited review and permitting. At the same time, innovative tools are needed by local governments to incentivize the adoption of bird-friendly building materials and design, especially on existing buildings. So, creating financial incentives for developers and homeowners could be a promising approach for accelerating the retrofitting of existing buildings. Many policy incentives designed to accelerate energy efficiency retrofits could also incentivize retrofits to make buildings bird-friendly. Some policy tools could be modeled on the energy-efficiency financial and structural incentive policies passed by many U.S. and global cities in recent decades aimed at reducing carbon emissions and heat-island effects in city centers.

Barges: Back in December 2022, advocates and leaders from around the world gathered in Montreal for COP15 to discuss strategies for protecting biodiversity. I believe that the urgency of taking action will be felt in more and more places around the country and around the world, leading many local and state governments — and hopefully soon the federal government — to pass policies that can help to protect bird populations and biodiversity in built environments — in our increasingly glassy human built spaces. We know that many species are under serious threat, with new research showing that many dozens of species will go extinct in the coming decades. It’s hard for us to imagine a world without the song of the Wood Thrush. And yet that is the reality facing us if we do not act soon and effectively to reduce the threats that birds face as they live in and migrate through the built environment.

Building Safer Cities for Birds: How Cities Are Leading the Way on Bird-Friendly Building Policy” is part of the Yale Bird-Friendly Building Initiative and is supported by a seed grant from the Yale Planetary Solutions Project, a campus-wide initiative focused on addressing the climate and biodiversity crises.