Do you want to help migratory birds? Turn off your lights

Light pollution is dangerous for birds flying over cities. Here’s how you can help

By KR Callaway edited by Andrea Thompson

Between March and June, millions of migratory birds head north along North American flyways. These pathways to heaven have been used for millennia. But as man-made structures proliferated, birds more frequently came into contact with the unpredictable glow emanating from windows and exterior lights.

Migratory birds often move at night, when they navigate using specialized cells capable of detect the earth’s magnetic field and take visual cues from the faint light of the moon and stars. Artificial lights disrupt this carefully tuned internal navigation system, knocking birds off their path and even trapping them in beams of light.

Each year, an estimate a billion birds die from colliding with windows, and countless others exhaust themselves trying to make their way through artificially lit spaces. This is a crisis for migratory species that are already facing steep population declines due to climate change, habitat loss and pesticide exposure. But during this migration season, you can help at-risk birds safely reach their spring breeding grounds by keeping the lights low.

On supporting science journalism

If you enjoy this article, please consider supporting our award-winning journalism by subscribe. By purchasing a subscription, you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

“Unlike many of these huge sources of mortality, like climate change, which individuals can’t influence as much as we’d like, we can really help solve the problem of nighttime lighting,” says SK Winnicki, an evolutionary ecologist and ornithologist at Ohio State University.

Artificial light at night affects the circadian rhythm of birds (and that of humans), as well as the animals’ sense of navigation. While these effects technically exist year-round, it’s not necessarily necessary to keep the lights dim year-round to make a difference, experts say. Attenuation of light pollution is greatest during migration peaks.

THE quantity of migratory birds overhead costs vary depending on the weather and where you are along the flyway. But generally, the number reaches its peak between two and four hours after sunset in spring and fall. During these times, the easiest way to help birds is to turn off unnecessary lights at night and close curtains or blinds to prevent indoor light from spilling outside. And to mitigate the harm of necessary outdoor lights, experts suggest making sure they’re facing downward or covered to prevent them from shining skyward.

“On these very, very intense migration nights, you can turn off lights that you don’t necessarily want to turn off all year round,” Winnicki says. “And once the birds are in town, we have to protect them. »

For birds that do not leave cities before the end of the night, one of the greatest dangers is colliding with a window while looking for a green space to rest. That’s what makes urban environments a “double jeopardy” for birds, says Devin Mingesbruney, program coordinator for Ohio Lights Out, a nonprofit bird conservation organization that works to mitigate light pollution.

“Everyone has stepped into glass at some point,” says Dustin Partridge, senior director of conservation and science at the nonprofit NYC Bird Alliance. “It hurts our ego, but for a bird it’s deadly… They run at full speed, head first, and they don’t perceive the glass.”

To help migratory birds during the day, experts suggest adding external markers that will make the glass more visible to fast-moving birds. These markers could be as simple as a grid of dots on the outside of the window or as complex as ultraviolet coatings that birds can see but humans cannot.

“It’s hard being a bird,” Partridge said. “We have built cities in their path, and that presents risks…, but these problems can be easily solved.”