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Decreasing Lighting Impacts

Photo courtesy U.S. NOAA


The presence of artificial light at night, also known as light pollution, is a danger to migrating birds, making them prone to colliding into buildings, homes, and other structures particularly in cloudy or foggy conditions. Birds become spatially disoriented by the false horizon created by artificial light and will fly towards backlit windows in an attempt to correct their flight. In a recent study, 1,297 birds died after hitting a 90-foot illuminated building in Chicago during a two-year period. In that same area, an unlit structure claimed just 192 birds during the study period. (Chicago has recently adopted a "Lights Out" program. See link below.) Michael Mesure of the Fatal Light Awareness Program estimates that at least 100 million birds are killed by manmade structures each year in North America.



Turn It Off

Turn off as many exterior and interior lights as possible during the peak migration hours of midnight to dawn. Encourage your neighbors to do the same. If you work in a high rise, contact building management and let them know about the dangers of illuminated buildings at night.

Direct It Where Needed

Outfit exterior lights with top and side shields to reduce upward and sideways illumination. Shields will direct light downward, where it is needed.


Further Resources:

FLAP: Fatal Light Awareness Program
Extensive information and resources on bird collision and light pollution issues

Audubon Magazine Mar-Apr 2000
The Dark Side of Light
by Joe Bower
Feature article on light pollution

Lights Out Chicago!
Describes the city's efforts and recommendations to reduce light pollution