Last week, over 18 million migrating birds passed over North Carolina in one night.
The fall migration season runs from Sept. 10 through Nov. 30, during which many songbirds in particular migrate south. But excess lighting from cities or towns can be a big hazard to their trip. So, the Audubon Society has a "Lights Out" program, asking residents to turn off excess artificial light at night.
The "Lights Out" program is an attempt to limit light pollution, where artificial light can drown out the light from many stars. The state’s Audubon engagement director Ben Graham said that starlight is crucial for migrating birds.
“These birds use the moon and stars to navigate,” Graham said. “Unfortunately, bright city lights can disorient them. And so, when a bird is flying through a city, the bird will fly around in circles, and sometimes collapse from exhaustion. Other times, fly into a building and fall down dead or injured.”
Graham added that the fall migration season is particularly hazardous, as inexperienced young birds are making their first migration journeys. The Smithsonian Migratory Bird Center estimated up to a billion birds each year are killed by colliding into buildings.
This includes species like the wood thrush, whose population has decreased by more than 50% since the 1970s.
“They are in steep decline, and there's a lot of reasons for that decline,” Graham said. “But one thing we do know from our surveys is that they are a common building collision victim in North Carolina. So, when we take some of these Lights Out measures, when we push our cities to adopt Lights Out programs, we're helping some of these vulnerable bird species.”
A 2021 study looked at one building in Chicago and estimated that it could reduce bird deaths at the site by 60% if the building reduced its window lighting.
To help migrating birds this season and next spring, Audubon North Carolina recommends turning off excess and decorative lighting, shielding or installing motion sensors on other lights, and advocating to employers to reduce nighttime office lighting as well.
According to Audubon, five N.C. cities and towns — Asheville, Chapel Hill, Greensboro, Matthews and Raleigh — have adopted Lights Out policies, committing to following Audubon guidelines and raising awareness to limit excess lighting.
Individual buildings in Winston-Salem and Charlotte have also adopted Lights Out policies.