Birds and the City

A common yellowthroat is a plump little songbird so tiny it might seem delicate. The weight of one resting in the palm of your hand would feel the same as two nickels. But these birds are robust and resilient, capable of flying for thousands of miles. In fall, they transform the bugs and spiders they eat in Canada or New England into fuel for grueling migration flights as far south as Central America.

During these demanding journeys, scores of common yellowthroats and other migratory birds fly over and through Baltimore City. The city is squarely within North America's Atlantic flyway, a thoroughfare for millions of birds heading south for winter and returning north in spring to breed.

Migration Is Risky Business for Birds

Cities are generally unsafe for migrating birds, and Baltimore is no exception. Many species, including common yellowthroats, migrate at night when temperatures are lower and predators scarcer. They rely on the moon and stars to navigate through the dark, but in cities, bright lights blaze inside and outside buildings, along streets and on vehicles. These artificial, all-night lights attract and disorient birds. Buildings' clear windows and reflective surfaces are difficult for birds to see, adding to the danger.

The toll of these dual threats is staggering. The American Bird Conservancy estimates that up to a billion birds die each year in the United States after colliding with glass. This happens in urban and rural environments, with commercial buildings and private homes. It's another factor, like climate change and habitat loss, causing North American bird populations to decline.

World Migratory Bird Day, which celebrates birds and underscores the need to conserve them, will be held for the second time this year on October 11. It was also observed on May 10 during the spring migration season. This year, World Migratory Bird Day highlights the need to create bird-friendly cities and communities. That's exactly what one National Aquarium partner, Lights Out Baltimore, has been working toward locally since 2011.

Making Birdland Bird Safe

Lights Out Baltimore is a nonprofit affiliated with the Baltimore Bird Club, a local chapter of the Maryland Ornithological Society. Its members aim to make Charm City safe for migratory birds by encouraging people to turn off unnecessary nighttime lights during the peak migration months of April, May, September and October. They also advocate for bird-safe buildings with surfaces birds can see.

Lindsay Jacks has volunteered as the executive director of Lights Out Baltimore since 2012. She's also the National Aquarium's executive office coordinator and previously worked as an aviculturist in Australia: Wild Extremes.

During fall and spring migration, Lindsay is one of about 10 Lights Out Baltimore volunteers who rise in the pre-dawn dark to walk through downtown Baltimore with nets, buckets and bags to pick up birds that have collided with buildings. Of every four birds they find on sidewalks, only one is usually still alive.

They take injured birds to licensed rehabilitators like the Phoenix Wildlife Center to be nursed back to health and released. They send dead birds to the Smithsonian National Museum of Natural History. Data about all the birds they find contributes to research about bird populations, migration patterns and more.

Common Misperceptions

"Most people think we find house sparrows and starlings," Lindsay says, "but really it's Baltimore orioles, common yellowthroats, white-throated sparrows and other neotropical warblers."

Another misperception is that birds that collide with buildings have broken necks or wings. Almost all of them have head trauma from flying full speed directly into a window. Also, homes and low-rise buildings cause far more bird deaths than high rises.

"The first 30 to 40 feet of a building is the threat for birds," Lindsay explains, "right in line with the trees where they're foraging and perching before seeing a reflection of the tree in glass."

The number of dead and injured birds found by Lights Out Baltimore volunteers in September and October is double or even triple the number they find in spring, which is consistent with findings across the Northern hemisphere.

"Birds that hatched during the spring breeding season make their very first migration in fall," Lindsay explains. "It's heartbreaking to find a juvenile and know they didn't survive their first journey."

Partners in Protection

The Aquarium partners with Lights Out Baltimore to make its campus safe for birds and advocate for city- and statewide conservation measures.

Aquarium buildings' exterior windows and glass surfaces have decals to make them easily visible to birds. The Aquarium also uses minimal nighttime lighting inside and out year-round. During peak migration season, the Aquarium dims its lights even more. Necessary lighting is warm amber or gold, better for birds, bats and bugs than bright white or cool-colored lights. Bird-safe lighting and decals were incorporated into Harbor Wetland from the start, within the exhibit and the surrounding area.

"We knew we were creating a habitat that would attract birds, so we wanted to mitigate any risks," Lindsay adds. "It would have been irresponsible to intentionally draw birds into an area where they might not be safe, which is true whenever you're adding green space that will attract wildlife."

Beyond our campus, the Aquarium and Lights Out Baltimore supported the Maryland Sustainable Buildings Act, which went into effect in 2023 and requires buildings to have bird-safe glass and lights.

What You Can Do

There are steps individuals can take to protect birds, too. Turn off all non-essential lights at night, use warm-colored bulbs, and add a shield or dome to exterior fixtures to prevent light from spilling skyward. Apply window decals or stick Post-its inside glass windows and doors. Move bird feeders within 5 feet of windows. If you find a stunned but alive bird in the Baltimore area, you can contact Phoenix Wildlife Center for help. You can report sighting of dead birds to Lights Out Baltimore using their online form. And if you want to learn more about the birds winging through our airspace this fall, Audubon's Bird Migration Explorer tool lets users follow the travels of thousands of individual migratory birds.

"There are small things each of us can do to protect birds," Lindsay says. "It's about thinking globally and acting locally. I can't control what's happening in New York or Chicago—but I can be part of the solution here in Baltimore."