Birds fly in front of the Lower Manhattan skyline on a cloudy day. Stephanie Keith/Reuters
New York City Will Require Bird-Friendly Glass on Buildings
Hundreds of thousands of migratory birds smash into the city's buildings every year. The city council just passed a bill to cut back on the carnage.
A dense city like New York can be a dangerous place for birds: Each year, up to 230,000 birds collide with its buildings, and many die as a result, according to estimates from New York City Audubon. In an effort to avoid many of those deaths, lawmakers just made the city one of the largest in the U.S. to pass bird-friendly legislation.
In a 41-3 vote on Tuesday, the city council passed a bill that will update the building code with design and construction requirements aimed at making buildings safer for migratory birds. It will require exteriors on the lowest 75 feet of new buildings, and on any structure above a green roof, to have avian-friendly materials such as patterned glass that make transparent surfaces more visible to birds flying at full speed. The bill doesn't include a mandate to retrofit existing buildings, but requires any future renovations to comply with the standards, which are set to take effect in December 2020.
Brooklyn Councilmember Rafael Espinal proposed the legislation with input from NYC Audubon, the American Bird Conservancy, and the city's chapter of the American Institute of Architects. "This bill strikes a careful balance in requiring bird-friendly glass only at heights where birds are most likely to be flying," Espinal said during a council committee meeting on Monday.
The legislation is a major step in addressing a critical concern among wildlife activists like Christine Sheppard, who directs the American Bird Conservancy's glass collisions program. North America has already lost 3 billion birds—or 29 percent of the avian population—since the 1970s due to a slew of threats that include climate change, habitat loss, and loss of insect prey. Window collisions play a role too: Some 600 million birds die each year across the continent after crashing into glass surfaces, according to a recent study by the American Bird Conservancy. Those passing through New York City are likely flying along the migratory pathway known as the Atlantic Flyway.
Sheppard, who advised New York's lawmakers in writing the bill, and her team will work with the city's building department over the next year as it develops specific guidelines. Her key concern is helping birds see glass surfaces. "Birds have eyes on the side of their heads, and they see different things with each eye," she says. "They don't have a lot of depth perception." They also haven't evolved to recognize glass as a barrier—skyscrapers have only cropped up over the last century—which means that when birds see the sky or a tree reflected in glass, they will continue flying towards it.
Sheppard's organization and others have advised architects to place netting in front of windows or use more subtle techniques like fritting, the application of ceramic lines or dots onto glass—changes that Sheppard says won't diminish the aesthetics of a building, but will jump out at birds as an obstacle around which they need to fly.
The Javits Center in Manhattan was renovated in 2014 using bird-friendly glass. (Steve Luciano/AP)
She points to Manhattan's Jacob K. Javits Convention Center as a success story. Its original all-glass facade killed nearly 500 birds between 2005 and 2009, making the building one of the deadliest in the city for the avian population. Then, as part of a five-year, billion-dollar expansion that was completed in 2014, the center was renovated with fritted, translucent glass panels, as well as a 6.75-acre green roof. By 2015, NYC Audubon found, the new design had reduced bird deaths by a whopping 90 percent.
There's another bonus to some bird-friendly redesigns: "Frit is primarily used to cut down on heat load, so that you spend less money on heating the building," says Sheppard. New York City passed an aggressive climate bill in May, focused on drastically cutting carbon emissions by improving energy performance of buildings; the city's bird-friendly and sustainability goals go hand in hand, Sheppard argues.
In 2011, San Francisco became the first major U.S. city to adopt standards for bird-safe buildings, though the city only made them voluntary. Since then, a handful of smaller California cities and the state of Minnesota have followed suit and developed similar ordinances. There's also been more clear evidence of what works in the past decade. "Ten years ago, we didn't have all the science or the material," Sheppard says. "But now we know that you can dramatically reduce [bird] collision using a pattern that covers less than 7 percent of the glass surface."
"Now we know that you can dramatically reduce [bird] collision using a pattern that covers less than 7 percent of the glass surface."
Architects have become more willing to incorporate bird-friendly elements into their buildings, Sheppard adds. "I do classes for architects and when I walk in, I can tell what these people are thinking: bomb shelters and warehouses with no windows," she says. "But by the time I'm done [with my lesson], they go, 'Oh, I can do that."'
Back in September, the Real Estate Board of New York expressed concerns about the cost and availability of the materials under Espinal's proposal, as well as the effects the bill could have on storefronts, which also have to comply with a minimum transparency requirement. The board called on lawmakers to conduct a more holistic study of the legislation's impacts. On the Saturday before the council's vote, a spokesperson told the Associated Press that lawmakers addressed their concerns in the bill's revisions. The board commended the council for supporting "a science-based approach to reducing bird deaths," and said the group intends to monitor the bill's implementation.
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Sheppard foresees more cities adopting bird-friendly standards, and believes there's an advantage to built-up New York having been among the first to do so. "If New York can do it, it becomes much more difficult for another city to say they can't do that, or that it's too hard," she says with a laugh. "Nothing is going to be as hard as getting this to work in a big, complicated city like New York."
@linpoonsays
Linda Poon is a staff writer at CityLab covering science and urban technology, including smart cities and climate change. She previously covered global health and development for NPR's Goats and Soda blog.