Up All Night at the 9/11 Tribute in Light, Looking Out for Birds

The middle of the night on the roof of a parking garage in the Financial District isn't where you'd expect to find some of New York City's most dedicated birdwatchers. But on Monday night, 116,100 birds crossed Manhattan as the annual 9/11 Tribute in Light memorial shone two powerful beams into the sky, and a group of bird lovers gathered to not just gaze at birds, but to keep them safe.

New York City is a dangerous place for birds; the oppressive glow of urban areas confounds their instincts, drawing them into hazards like vehicles, predators, and reflective or transparent windows. As many as 230,000 birds die in the city from window collisions each year alone, according to NYC Audubon. But September 11 can be an especially rough day for birds, thanks to the twin lights of the annual memorial.

September 11 just so happens to land in the midst of the fall migration season, when vast numbers of North America's birds, many of which migrate at night by making use of the light of the moon and the stars (among other navigation guides), wing their way southward. On Monday, as in years past, thousands of migrating birds, mere specks high above the parking garage where the memorial is held, became ensnared in the beams over the course of the night. Flapping in panic through the lights, they veered in circles, ellipses, and figure-eights, calling to one another in confusion. 

Below them, a squad of about 20 bird lovers had gathered to keep watch and protect them. Some were professional scientists, others were volunteers: amateurs and hobbyists. Some worked in shifts, others took intermittent naps, others stood sentry all night long—fueled by pizza, donuts, and plenty of caffeine.

The observers at the Tribute in Light on Monday night have learned over the years how to mitigate the risk that the memorial poses to birds: by temporarily shutting off the beams, a protocol that NYC Audubon has negotiated with the memorial's organizers. If there are too many birds trapped, or if they're circling dangerously low, the lights are extinguished for 15 to 20 minutes to give the flocks time to disperse. This year, the lights had to go out four times, as "a perfect storm of circumstances"—recent storms, low clouds, and light winds—brought in high volumes of migrating birds, according to NYC Audubon Executive Director Jessica Wilson.

One of the volunteer observers on the ground was Tim Healy, a high school science teacher in Queens with a lifelong obsession with birds (the first word that Healy spoke as a child was "bird," he told me). Despite the impact of the memorial on birds, he's by no means against it, which he sees as a meaningful symbol of resilience and remembrance, as well as another way of introducing people to the need to protect the environments around them.

"It's a matter of being respectful to what this site means and what this day represents, as well as gathering useful scientific data, and making sure that we're continuing to learn and be stewards of these migratory birds that are affected by it," Healy said.

Darlene Juliao, a 24-year-old data analyst, was one of several birders attending the Tribute in Light for the first time this year. In a previous job with the Wildlife Conservation Society at the Bronx Zoo, her fascination with animals developed into a birdwatching passion. A friend working at NYC Audubon had encouraged her to volunteer at the memorial this year. 

The remembrance holds particular significance for Juliao and her family—she lost a cousin in the September 11 attacks. Now, she said, returning to the memorial to help protect birds meant that things were coming full circle.

"I'm doing it for the birds, because I love the birds, but it's also close to my family," Juliao said.

At the same time, she wondered if the Tribute in Light was the best way to honor victims like her cousin. "As tragic as it was, we don't want any other deaths—like, environmental deaths," she said.

While it seems reasonable to assume that some birds that become disoriented and exhausted by the beams of light are more likely to die in migration, any harm to birds caused by the memorial is difficult to separate from other factors in the urban environment that are constantly killing them—for example, empty, brightly lit office buildings. Monday night, staff and volunteers watched as a black-and-white warbler brushed against death, as it circled in the lights before striking the reflective shell of 50 West, a glass-coated luxury condo building adjacent to the north beam of light. It plummeted to the roof of the parking garage, alive but injured. NYC Audubon staff placed it in a paper bag—the recommended procedure—and arranged for it to be transported to the Wild Bird Fund in the morning for treatment.

A little after 1 a.m., I walked around the roof of the parking garage, peeking over the wall to look for any other victims. On a patio outside 50 West, I spotted one: another black-and-white warbler, this one dead on its back. Cast in dull yellow light from an adjoining hallway, it lay with legs splayed and wings clutched to its sides, its back arched.

Half an hour later, NYC Audubon's Director of Conservation and Science Dustin Partridge pointed out a dead American redstart outside another window of the same building. But he noted that both of the dead birds could have struck the windows on previous nights—it was impossible to say if the beams caused their deaths.

It was clear, though, that some birds were hitting windows. Around 4 a.m., I was tracking the flight of yet another black-and-white warbler through my binoculars. My heart sank as it flapped first toward, then near, then right into 50 West, striking the glass head-on. It recovered from a midair tumble and flew off again. I had been hearing groans throughout the night from helpless observers watching birds collide with that building—how many wouldn’t recover?

The problem doesn’t lie just with that particular building alone, nor with the Tribute in Light. The tribute shines 88 industrial-strength xenon spotlights onto an existing threat.

"Because of the brightness of it and the intensity, it's definitely extreme—but this happens every night," said Andrew Farnsworth, a leading bird migration researcher at Cornell University's Lab of Ornithology.

The concentration of birds, observers, and technology around the Tribute in Light have made it into an outdoor laboratory for Farnsworth and his colleagues to conduct migration research. Weather surveillance radar, thermal imaging, acoustics recording, photography, and good old-fashioned visual observation are all employed at the site, where the dazzling beams cast light onto some of the myriad mysteries of bird migration.

Researchers here have observed that birds attracted to the beams increase the frequency of their flight calls, fly more slowly than usual, and aggregate in significantly higher densities. Crucially, they've found turning off the lights for just 20 minutes just about completely allows the birds to disperse.

Farnsworth and NYC Audubon's Partridge both emphasized the role that findings from the Tribute in Light have played in making cities safer for birds.

Reducing light pollution on every night of migration season—not just the high-profile beams—can help prevent birds from becoming disoriented by the city's lights, experts say. Every little bit does count, but legislation to reduce light pollution during periods of intense migration would have the greatest impact, Partridge said.

"If we want to be serious about reducing or stopping that quarter-million birds that are dying every year, we really need lights to go out in the city," Partridge said.

The data gathered at the annual memorial by trained scientists and volunteer monitors alike has supported advocacy for lights-out initiatives in New York and other cities like Dallas and Denver. And data aside, there's something about witnessing the spectacle of migration, arrested in the lights like a tractor beam, that can motivate change.

"It's horrifying, of course, just seeing how many birds are being stopped from migrating properly," said Elias, a 13-year-old volunteer. "But also, I think it's amazing to see the force of migration."