‘Lights Out’ initiative appears to be saving birds from crashing into Philly buildings

The effort to darken buildings at night to protect migrating birds appears to be working, but organizers say more long-term data is needed.

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flock of birds in flight


Lights Out Philly, an effort to reduce the number of birds that die crashing into buildings in Philadelphia, appears to be working.

The past two spring and fall migration seasons, Philly-area organizations have convinced building owners and managers to turn out the lights at night, so that birds don’t get disoriented and fly into the glass.

“We think it’s working,” said Keith Russell, program manager for urban conservation with Audubon Mid-Atlantic, one of the organizations behind Lights Out Philly.

Organizers have started collecting data, and say it looks promising. They announced early results at a preview of a new bird-themed exhibit at Drexel’s Academy of Natural Sciences, called “Conversations With Birds,” which opens Saturday and runs through late May.

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Part of the upcoming Conversations With Birds exhibit at the Academy of Natural Sciences of Drexel University (Sophia Schmidt/WHYY)

At one building on Market Street that cut its light the most, bird collision deaths in the fall dropped around 70% since 2020, according to the collaborative. Russell emphasizes that these results are preliminary.

“If we can continue monitoring for a couple of years and we see that this reduction continues, then we have more confidence that it’s the lights, and not anything else,” he said.

Because of its location along one of the country’s four major migration “flyways,” Philadelphia can see millions of migrating birds each year. Birds use the stars to navigate, but can get disoriented by city lights. They can try to fly through reflective or transparent glass, and get injured or die.

Researchers have found that these behavioral disruptions can disappear when lights are turned off. One study that focused on a large building in Chicago modeled that decreasing the lighted window area could reduce bird deaths by around 60%.

The precise number of birds that die from flying into buildings each year in Philly is not known, Russell said.  But any reduction in the number of bird collisions is important, he said, when overall bird populations in the U.S. and Canada have dropped by billions in the last five decades.

“We’ve lost almost a third of our birds — and [bird collisions are] contributing to that,” Russell said. “If we’re going to want to preserve the bird populations here in North America, we have to look at these types of problems. And this is a preventable one.”

Philadelphians can contribute to data about bird collisions by logging observations with the Bird Safe Philly Bird Strikes Project on the platform iNaturalist.

Lights Out Philly will happen again this spring and fall — starting April 1.

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The Academy of Natural Sciences’ “Conversations With Birds” exhibit includes live and video demonstrations of dissections and necropsies of birds that died flying into buildings, activities for kids, live bird migration forecasts, and opportunities to connect with local birding groups. 

“The message is that birding is for everyone,” said Marina McDougall, vice president of experience and engagement at the Academy of Natural Sciences.

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