Georgia Audubon has a new tool to help minimize bird collisions with buildings and to alert the public to dim the lights on nights of high bird migration. Thanks to a collaborative venture between Georgia Audubon and Dr. Kyle Horton at Colorado State University, it is now possible to predict nightly bird migration over the state. Georgia Audubon has begun issuing Lights Out Alerts on nights of elevated migration intensity. This work was funded through a generous grant from the Disney Conservation Fund.
Atlanta is a dangerous place for migrating birds, ranking as the 4th most dangerous city during fall migration and 9th in spring for light exposure to migratory birds, according to a 2019 study by the Cornell Lab of Ornithology. With an estimated 250 million birds passing over Georgia during spring and 675 million birds migrating over in the fall, it is vital to learn about migration over our state and make our cities safer.
Over 80% of all migratory species in Georgia are affected by light pollution. The forecast map shows both the relative scale of migration intensity across the state as well as pinpointing specific areas of intense bird movement. The map has a three-level classification (low, medium, and high migration). The current collision forecast shows that 50% of migrant birds historically pass through the Atlanta metro from September 23 - October 17, 2021.
Each year, an estimated 365 million to 1 billion birds die in the U.S. after colliding with buildings. Most migrating birds pass through Georgia during the nighttime hours, when skies are generally calmer, predators are less active, and temperatures are cooler. Large, brightly lit cities wreak havoc on migratory birds as the ever-present glow of artificial light turns the normally safe nighttime sky into a perilous pathway. Bright lights confuse and disorient resident and migrating birds as they pass over brightly lit cities causing birds to collide with structures or become trapped in beams of light where they circle until they are exhausted. Once on the ground, brightly lit building lobbies, reflective glass showing trees and shrubs, transparent facades, or even indoor plants near windows can lead to more collisions.
In an effort to reduce the number of bird-building collisions, Georgia Audubon launched Lights Out Georgia in spring 2017. A voluntary program, Lights Out Georgia encourages business owners, building managers, and residents to turn off or reduce lighting from midnight to dawn during peak bird migration periods. Participants pledge to reduce non-essential lighting during peak migration periods of March 15 to May 31 (spring) and August 15 to November 15 (fall). The pledge is available on the Georgia Audubon website. Lights Out Alerts are also posted on the Georgia Audubon Facebook page or the Colorado State University website.