About 160,000 birds get trapped in the 9/11 lights every year. Many of them die from injury or exhaustion.
Every September, two powerful beams of light illuminate Manhattan’s sky to commemorate the World Trade Center’s Twin Towers and those who perished on 9/11. But while those rays of light might help the affected process trauma, they’re potentially endangering 160,000 birds a year.
Those who’ve visited the site while the illuminated tribute is underway are familiar with the plentitude of birds swooping across and around the shafts of light. They’re naturally drawn to it, just like bats and insects are.
But, unfortunately for the birds, the anniversary of the September 11 attacks coincides directly with many of their migratory paths across New York City. A 2017 study published in the journal PNAS found that across seven anniversary nights between 2008 and 2016, the migrations of up to 1.1 million birds were affected.
The disorienting effect on their navigation has been found to cause both injury and exhaustion. Many have flown straight from the light beams and into nearby glass buildings.
“They only have enough to get where they need to go; the fatter you are the more energy it takes to fly, so it’s a fine balance,” said Susan Elbin, an ornithologist and the director of conservation and science at New York City Audubon. “Light lures them in, and glass finishes them off.”
Elbin, who along with other scientists has conducted radar-based studies to find a feasible solution.
Every night the lights are on, a team of professional scientists and volunteers uses radar, binoculars, and plain sight to count the birds trapped in the light — which include Canada and yellow warblers and American redstarts. Bats, nighthawks, and peregrine falcons show up, as well.
When the number of birds reaches 1,000, the lights are turned off for 20 minutes to give the birds enough time and darkness to resume their natural migrations.
“It’s my job to turn the lights out, and I’d rather not have lights on at all, because the artificial light interferes with birds’ natural cues to navigate,” said Elbin.
The scientific community’s work at the 9/11 memorial comes at a time of growing awareness about the effects of human-made structures and light pollution on the world’s ecology. According to NYC Audubon, up to 230,000 birds collide with NYC buildings every year.
Earlier this week, New York’s City Council held a committee meeting on a bill that would require new or renovated buildings to use bird-friendly glass. Chicago is considering a similar law.
Sara Crosby joined NYC Audubon’s Project Safe Flight in 2007 after finding a dead bird on the sidewalk. She described her first 4 a.m. to 6 a.m. shift at the 9/11 memorial as a mix of “bird people with their yoga mates” and “lots of scientists being science-y.”
“I was here for 9/11,” she said. “I saw the second plane. I’m not ‘anti’ tribute. But a tribute that kills thousands of birds? Is this really what we want?”
After learning about how the 9/11 tribute lights endanger the lives and migrations of thousands of birds every year, check out these 9/11 photos that reveal the tragedy of America’s darkest day. Then, read about how dozens of dead birds fell from the sky in Australia bleeding from their eyeballs.