Building lights can be very dangerous to the billions of birds that migrate at night. The reason is that they disrupt your natural navigation signals causing fatal collisions . The reality is that all the lights in the buildings cannot be turned off, but some windows can, especially during migration periods. This gesture would save the lives of many birds.
A study published this week in PNAS has shown that just having a building half its windows lit up can significantly reduce night-time bird collisions.
Over 21 years the building under study, McCormick Place, a three-story convention center, in Chicago, suffered 11 times fewer nighttime bird collisions during the spring migration and 6 times fewer collisions during the fall migration compared to When all the windows had light
The current director emeritus of collections for the Field Museum of Natural History, Dave Willard, began collecting dead birds from around McCormick Place in 1978. Today there are 40,000 the number of birds that rests in a drawer in the Field Museum. Since 2000, these records also include information about the windows that were lit when each bird died. By comparing these McCormick Place data with other collision risk factors, such as weather conditions, moonlight, and intensity of migration, researchers have been able to determine which conditions are the most deadly for migratory birds.
It was found that when there are more birds migrating, more collisions occur, as well as when the west wind blows. Of course, the shocks increase the larger the area of the windows that are illuminated.
Benjamin Van Doren, lead author of the research, highlights “the exciting potential of saving birds simply by reducing light pollution .” In the United States, more than thirty cities have joined initiatives that promote lights out ( Lights Out In Philadelphia, for example, landlords and tenants are encouraged to turn off unnecessary lights during migration seasons between 12 p.m. and 6 a.m. Emphasis is placed on lights on upper floors, the lobby and the atrium, both internal and external lighting.Lights Out Chicago, meanwhile, is one of the oldest lights-out initiatives in North America.
The researchers hope to be able to raise awareness among citizens by issuing local migration alerts in which it is notified in advance which nights large movements of birds are expected in order to be prepared and turn off the lights (or dim them) as much as possible.
Fuente: Drivers of fatal bird collisions in an urban center. Benjamin M. Van Doren, David E. Willard, Mary Hennen, Kyle G. Horton, Erica F. Stuber, Daniel Sheldon, Ashwin H. Sivakumar, Julia Wang, Andrew Farnsworth, Benjamin M. Winger. Proceedings of the National Academy of Sciences Jun 2021, 118 (24) e2101666118; DOI: 10.1073/pnas.2101666118
