This time of year, tens of thousands of migrating birds are passing through the District on any given night. Attracted by artificial lights, hundreds of these birds are killed annually in collisions with the city’s buildings.
“The bottom line is that birds simply don’t see glass,” said Anne Lewis, founding president of the D.C. nonprofit City Wildlife. “These birds migrate at night, and they tend to hit the buildings early in the morning when they’re coming down to rest.”
For more than 10 years, City Wildlife’s Lights Out DC project has been steadily collecting data on bird collisions — a task that requires volunteers to start on a miles-long walk at about 5:30 a.m. once a week. The effort paid off last year, when citizen science data helped convince the D.C. Council to pass the Migratory Local Wildlife Protection Act.
The law, which Lewis said is modeled after a similar one enacted in New York City, mandates that new buildings or significant renovations meet certain bird-safe design standards. For the most part, this means using glass with patterns or ultraviolet coatings (which birds can see but people can’t) on windows below 100 feet. The law required the Department of Buildings to issue specific regulations.
The new policy was initially set to apply to all permit applications submitted after Oct. 1, but earlier this fall, the D.C. Council added a clause into a seemingly unrelated bill — the Protecting Historic Homes Amendment Act — that pushes the implementation date back to January 1, 2025. The Council unanimously passed the Protecting Historic Homes legislation in a final vote on Oct. 1.
“This will give developers more certainty as to when the law applies to permits, and it gives the Department of Buildings additional time to implement necessary system changes,” Chairman Phil Mendelson said of the timeline change during a Council meeting Sept. 17.
In testimony at a 2022 hearing for the Migratory Local Wildlife Protection Act, District of Columbia Building Industry Association CEO Liz DeBarros urged the Council to extend the timeline for implementation. Last month, at a hearing about the Protecting Historic Homes Amendment Act, DeBarros gave testimony in support of delaying the bird-friendly building requirements.
In an emailed statement, a Department of Buildings (DOB) spokesperson said that the adjustment would “help ensure DOB’s proper incorporation and implementation of the Act into its building permit processes.”
The Department of Energy and Environment, which will collaborate on developing the regulations, did not respond by press time to requests for comment.
“I know the [Department] of Buildings is working on the permitting procedures and that’s why the delay,” Lewis said in an email. “In all events, we are happy that it has a concrete date not so long from now.”
Citizen Science Pinpoints Problem Buildings
The new law won’t impact existing buildings, unless they have major renovations; in big commercial buildings, it’s far more cost-effective to install bird-safe windows from the beginning than to retrofit them later, Lewis said.
During her pre-dawn walks every Tuesday, Lights Out DC volunteer Jennifer Melot has a list of problem buildings along her approximately 4-mile route. Starting near Union Station at about 5:45 a.m., she scans the ground around these buildings for fallen birds.
“Buildings I used to think were very beautiful — I used to think the glass, and plants, and lights were very nice — now I look at them like ‘oh, death trap,’” said Melot, who’s now in her third year as a Lights Out DC volunteer.
When The Informer joined Melot for her walk on Oct. 15, she found three fallen white-throated sparrows — one at the Thurgood Marshall Federal Judiciary Building next to Union Station, and two around the glass pavilion outside the D.C. Courts building at Judiciary Square. The previous week, Melot said, she found nine birds along her route.
Like other volunteers on the Lights Out DC team, when Melot finds a bird, she puts on gloves and carefully places it in a plastic bag, labeling it with the species name. If the bird is alive, volunteers carefully tuck it into a padded paper bag and bring it to City Wildlife for rehabilitation.
Tracking where the birds have fallen allows advocates to identify buildings that cause the most issues.
“There’s always a little bit of mixed feelings. … I don’t want to find any birds, but if they’re there, I do want to find them,” Melot said.
Buildings are most dangerous for birds when lights are highly visible at night; the artificial glow attracts birds and throws off their navigation. The other big risk factor is having lots of glass that looks fully transparent or highly reflective of nearby sky and trees.
Skywalks — enclosed bridges connecting two different sides of a building — pose a particular issue when they have glass on both sides, making the structure appear clear all the way through.
Melot said that buildings with visible indoor gardens or trees, like the gorgeous Thurgood Marshall building, can also cause issues for birds seeking rest.
Lights Out DC volunteers rarely find year-round city-dwelling birds in their collision tracking. Along with the white-throated sparrow, other migrating species that commonly crash in the District include the American woodcock, Ovenbird and Common Yellowthroat.
“They’re not used to cities — most of these birds are coming from grasslands and parks where they’re not used to the urban environment,” Lewis said.
What We Can Do About It
Unlike commercial buildings, most single-family homes where collisions are common can become bird-friendly at fairly low costs.
A 100-foot roll of patterned tape, which needs to be stuck on the outside of a window to make it visible to birds, is less than $20 from Feather Friendly. Another effective method, called a “zen curtain” or Acopian BirdSaver, entails hanging lengths of nylon cord outside a window, spaced about 4 inches apart.
“It’s much harder to identify how many birds a year are killed [hitting] sliding glass doors,” Lewis said. “And people think, ‘oh, well, one sad accident, but there’s nothing you can do.’ Well, there’s plenty you could do about it.”
Some of the commercial buildings that Lights Out DC monitors have also made changes based on the organizations’ work. Even small adjustments can make a big difference.
A 2019 report from City Wildlife said that when the group contacted the Architect of the Capitol about bird deaths around the Thurgood Marshall building, agency personnel agreed to turn off all but the necessary safety lights at night. Bird deaths at the building dropped by two-thirds afterward, though it remains a hotspot for collisions.
“The [Walter E. Washington] Convention Center had a big problem here that we identified early on, and they chose to retrofit,” Lewis said. “It wasn’t mandated, but they didn’t like being one of the prime killers of birds in the city, and so they voluntarily retrofitted certain dangerous windows that they put film up on.”
The convention center’s changes caused an 85% reduction in bird deaths at the building, Lewis said. Other buildings have made tweaks like dimming lights during migration season and switching from red exit signs to green ones (constant red light is disorienting for many bird species, and attracts hummingbirds in particular).
Building collisions are one of the top human contributors to bird fatalities, only after habitat loss and killings by outdoor cats. A study published in the journal PLOS ONE in August found that over a billion birds die each year from hitting buildings in the U.S., contributing to a steep decrease in bird populations across North America.
More than 51 cities around the U.S. and Canada have Lights Out programs dedicated to addressing the problem.
Lewis pointed out that functioning ecosystems are critical for human well-being, too — birds in particular help to keep pests under control and pollinate plants.
“People are not evil — they don’t want to kill birds, but they may not know and may not be aware of the threats,” Lewis said. “So education is a big deal in wildlife work. We need to inform people about what the needs of these animals are and also what the benefits are to people, because they’re enormous.”