Bird Collision Crisis in Chicago Sparks Call for Bird-Friendly Building Design

Advocates and volunteers report that over 1,000 birds were killed or injured after colliding with buildings in the Chicago area during fall migration this past weekend. The majority of these incidents occurred in downtown Chicago and Northwestern University’s Evanston campus on Saturday and Sunday, according to the Chicago Bird Collision Monitors. Volunteers had anticipated that north winds on Friday night would encourage many migratory songbirds to fly south, preventing them from overexerting themselves and burning large amounts of energy.

The DuPage Wildlife Conservation Center received 274 birds on Saturday alone from building collisions in downtown Chicago, followed by 60 more on Sunday, according to a spokesperson from the county’s Forest Preserve District. These new patients encompassed over 20 bird species, including 80 golden-crowned kinglets and 73 brown creepers. Jennifer Bell, a volunteer for the collision monitors, observed birds falling at an alarming rate, stating that birds were falling every five seconds. Between sunrise and 1 p.m. that Saturday, she picked up 22 live but injured birds along with 40 dead ones.

Advocates emphasize the urgent need for effective preventive measures, specifically calling for a Bird-Friendly Building Design Ordinance to establish protections for new buildings in Chicago. Beyond policy actions, they advocate for design choices and reducing light pollution in existing buildings to avert preventable collisions.

Chicago is identified as the most hazardous U.S. city for the millions of birds migrating along the Mississippi Flyway in spring and fall, according to Cornell University’s renowned Lab of Ornithology. BirdCast data shows that over 5 million birds crossed Cook County on Friday night during migration.

Annette Prince, director of the collision monitors, stresses Chicago’s significance along migratory routes, noting that birds have evolved to travel through this area for decades. Prince emphasizes the need to create a safe passage amidst beautiful architecture, ensuring the safety of the birds the city hosts.

Experts estimate that windows in the United States account for the deaths of a billion birds each year. BirdCast data indicates about a billion birds were in flight over the contiguous states Friday night. A similar tragic event occurred in Chicago three years ago when 960 birds collided with McCormick Place Lakeside Center.

Early October 2023 marked the most recorded bird collision deaths in the country during a single event. Jennifer Bell recounted that the recent event had a similar feel, having rescued 350 birds herself through her work with the collision monitors. Prince reiterated that the problem spans beyond downtown areas or tall buildings; birds can collide with glass up to 100 feet above the ground.

Doug Stotz, a retired senior conservation ecologist from the Field Museum, explained that a steady stream of individual bird casualties at many buildings contributes to the issue. Prince elaborated that glass buildings are perilous due to reflections that deceive birds into thinking the area is safe.

With birds flying as fast as 30 mph into glass, fatal injuries are imminent. Artificial lights in cities can disorient birds at night. Allison Sloan from Bird-Friendly Evanston emphasized the urgency of the situation, bagging 42 live but injured birds amidst dead ones around Northwestern University’s Evanston campus.

In March, Ald. Maria Hadden introduced an ordinance to amend the city’s building code, requiring bird-friendly designs on non-residential and high-rise buildings. Sponsored by Brian Hopkins and Ruth Cruz, co-sponsored by 18 City Council members, the ordinance now awaits a vote in the zoning committee led by Ald. Gilbert Villegas.

The ordinance proposes that bird-friendly buildings can offer vital protection, much like other safety features. Prince laments that the deaths are unnecessary, given known solutions that are not implemented. While opponents claim added costs, proponents argue bird-friendly design can augment development budgets minimally.

Visible treatments such as patterned glass or exterior screens are recommended to help birds recognize windows as barriers. After the 2023 incident at McCormick Place, developers applied markers to reduce bird collisions by 95%. Despite this, Stotz asserts that the issue persists, underscoring the necessity for the ordinance.

Since 1995, measures like the Lights Out Chicago program encourage turning off or dimming non-essential lighting overnight during migration periods, saving many birds from disorientation. Prince hopes new regulations will inspire existing buildings to adopt bird-friendly retrofits. She stresses the urgency of enacting these measures, advocating for immediate action to prevent further loss.