The nation’s capital wants building owners to be smarter.

A new law proposed by the Washington City Council aims to prevent hundreds of migrating birds from slamming against windows and falling to their deaths, DCist reported. New buildings should include materials qualified as “bird safe” to prevent such collisions, including screens or decals on glass visible to birds, or films and coatings to make windows less reflective .

The Migratory Local Wildlife Protection Act would apply to new buildings and those undergoing major renovations. It targets commercial buildings, multi-unit residential buildings, institutional facilities and city-owned structures, not single-family homes. The changes add little to construction costs and can increase energy efficiency.

The proposal comes after volunteers from local nonprofit City Wildlife found 4,500 birds over the past decade killed or injured after colliding with glass buildings within a 13-mile radius. blocks between Union Station and Chinatown. In 2012 they collected 200 birds. After a flurry of construction projects, the annual number of bird casualties rose to 700.

“We know that universal mandates that bird-friendly glass be used in construction could prevent the unnecessary death and injury of millions, if not billions, of birds,” the legislation says. “The district can do its part by prohibiting the use of hazardous building materials that put birds and other migratory wildlife at the greatest risk.”

Washington would join other cities with bird-friendly policies, including New York and Portland, Oregon, as well as Minnesota and Illinois.

Collisions with buildings are among the top human threats to birds, killing an estimated 365 to 988 million birds each year, according to a study by the Smithsonian Institution and the US Fish and Wildlife Service.

In Washington, most birds that collide with buildings are migratory, flying north or south along the Atlantic Flyway, according to City Wildlife. They include white-throated sparrows, lambskin birds, common yellowthroats, and woodcocks.

“They fly at night and they descend and land in our cities, and they’re not used to these urban canyons – these glass canyons – that we have for them,” said Anne Lewis, president of City Wildlife. “They don’t see the glass, so they crash into it.”

Lewis said two things make glass dangerous for birds.

“The first is that it’s clear and the birds can’t see it, so they think they can fly through it,” she said. “And the other is that glass can act like a mirror and is reflective, and in that case very often they see trees reflected in the glass and they try to fly into the trees.”

A 2019 study in the journal Science found that 30% of the bird population in the United States and Canada has disappeared since 1970, a loss of nearly 3 billion breeding adult birds.

[DCist] – Dana Barthelemy