It often takes a camping trip or a nighttime drive along a quiet stretch of highway to remind us just what a striking presence the moon and stars are. In metropolitan areas, the night sky just doesn’t look the same, especially because of all of the artificial lighting within the built environment.
But for winged creatures making their way through the sky, those lights in the universe provide more than mere scope for the imagination. It’s an important piece of how they navigate their path. And when artificial lights and skyglow from below interfere, that can create real problems, especially during May and September, the peak migratory months for songbirds.
When the birds get to a major city like St. Louis, light pollution can cause them to become disoriented or exhausted, and sometimes die.
“Bright city lights can confuse birds and distract them, and further cause them to be attracted to city areas when they fly, because that blocks what they use to navigate naturally,” Jean Favara, vice president of conservation for the St. Louis Audubon Society, explained on Thursday’s St. Louis on the Air.
While scientists are still studying why these birds migrate at night, some hints about the behavior are emerging. One of those has to do with the fact that it is cooler at night.
“As you can imagine, flying is highly energetic, so it’s easier for them to stay cool at night,” Favara said. “And another thing that migration at night does is it helps them to avoid predators that would be after them during the day, such as hawks.”
But even as the songbirds seek safe passage in the dark, some of them fall victim to the impacts of light pollution. The problem has the Audubon Society partnering with organizations including the Missouri chapter of the International Dark-Sky Association, through an effort dubbed Lights Out Heartland, to encourage businesses and individuals in the Midwest to turn off exterior lights during May and September.
Even the Gateway Arch will go dark — with its spotlights turned off in early May and late September — to help keep birds safe.
Don Ficken, president of the Missouri chapter of the International Dark-Sky Association, offered some tips for individuals.
“If you have lights, turn them off if you can. That would be a really good step to start with,” he said. “If you have to have lights on — maybe you’re worried about safety — put them on some kind of controlled mechanism … [and] make sure you’re targeting it specifically to the area that you need to have. Why light up the whole sky, for example, above you?”
The color spectrum of the light matters as well, Ficken added.
“As humans we have a fairly narrow range of light that we see, whereas animals have a much broader range,” he said. “And so when we get these really white and blue lights, it doesn’t look necessarily uncomfortable to us, but for creatures, for wildlife out there, it can really mess things up for them.”
In addition to partnering on Lights Out Heartland, the St. Louis Audubon Society has been working in recent days on its Bird Safe St. Louis project. That involves volunteers looking within an eight-block section of downtown for birds that have hit buildings and may be injured or dead.
“Last fall was our first set of surveys … and this year we just got started about a week ago, and we anticipate going through the end of May,” Favara said, describing the surveys as an important tool “to understand where in the landscape the birds are having trouble” in downtown areas.
The conversation also touched on observed changes in bird behavior in a time of less traffic and noise amid the COVID-19 pandemic — and humans’ growing interest in birds.
Bird feeder sales are up, Favara said, and activities like bird-watching have become an increasingly popular activity over the past year. And the birds seem to be showing up for it.
“Birds have been changing their song in response to the quieter environment they’re now living in,” Favara said. “They often are now singing in a few decibels lower than they did when noise was [so] present, and they can make their songs more variable and have more flourishes in those songs. … There are even studies now following up to see if that could lead to better [defense] of territories by these birds and better ability to attract mates.”
A local listener, Mary, shared a few of her recent bird observations.
“This year at home, birds have become more important,” Mary wrote on St. Louis on the Air’s Facebook page. “The regular finches and sparrows became like family. Now with migration they are coming back home. When I’ve felt trapped, I see the red-tail hawk circling our neighborhood and it gives me a lift. ... I feel free for a moment! So many people are putting bird feeders out to bring the feathered community closer. I’m hoping that love lasts long after COVID is gone. The day we saw a bald eagle over Kirkwood Park was pure magic!”
“St. Louis on the Air” brings you the stories of St. Louis and the people who live, work and create in our region. The show is hosted by Sarah Fenske and produced by Alex Heuer, Emily Woodbury, Evie Hemphill and Lara Hamdan. The audio engineer is Aaron Doerr.