Light pollution isn’t just bad for the environment: It’s also killing the birds.
By Danielle Braff
(Chicago) One by one, the birds fly happily toward Chicago’s McCormick Place, just south of the Loop. And one by one, they hit the convention center and fall to the cement, dead.
“Birds are attracted to lights, for reasons no one is sure about,” says David Willard, the retired collection manager for the bird division of the Field Museum of Natural History in Chicago. Willard, who has been studying the bird collisions at McCormick Place for the past 40 years, found that the location of the building, combined with the fact that they leave the majority of the lights on overnight - creates the unfortunately yet deadly situation.
McCormick Place’s location on the shore of Lake Michigan is an unfortunate factor, Willard says.
“If the winds during the night have pushed these nocturnally migrating birds to the shore or out over the lake, McCormick is one of the first things they will see as they work their way back to land,” Willard says.
On his own way to work each day, Willard says he stopped by the convention center, where he spotted up to 200 dead birds each morning. The windows that had lights left on overnight attracted the largest number of birds.
The good news: The bird deaths are totally preventable.
A new study published in June 2021 in Science Daily found that turning off the lights in the buildings drastically reduces the number of bird collisions. The researchers found that on the nights when half the lights were turned off, there were 11 times fewer bird collisions during the spring migration, and six times fewer collisions during the fall migration than when the lights were on.
Benjamin Van Doren, the postdoctoral associate at the Cornell Lab of Ornithology - and the lead author of the study, says that if McCormick Place (and other large buildings) turned off their lights at night, they could potentially save millions of birds daily.
“Billions of birds migrate at night, and scientists have known for a while that light pollution can dramatically affect bird migration,” Van Doren says. “Birds migrating at night are frequently attracted to and disoriented by lights on the ground, which puts them at risk to collide with lit structures. In fact, building collisions kill hundreds of millions of birds each year in the United States alone.”
Realistically, the study found that turning off the lights would result in 60 percent fewer bird crashes - but this doesn’t affect McCormick place alone. Other buildings could take the results of the study, and apply them to their own night lighting by turning as many lights off as possible, Willard says. They should also understand that it’s not just outdoor, ornamental lighting that can be problematic, but also internal lighting (which is the source of the issue at McCormick Place), he says.
To help with the bigger lighting issue, Van Doren says new initiatives such as Lights Out programs and campaigns are gaining momentum in North America. These initiatives encourage buildings and the public to turn out unnecessary lights to save birds, Van Doren says.
There’s also now a LEED building credit specifically focused on bird-safe building design, which includes bird-safe glass and light reduction among its criteria.
Van Doren says that while turning off lights between the hours of 11 p.m. and 6 a.m. is important - simply using blinds and curtains is also effective.
If you find an injured bird, place it in a box or in a paper bag, and contact the Chicago Bird Collision monitors at 773-988-1867. They will take the bird to a wildlife center for a wellness check before releasing it.