Cities' lights-out policy (for skyscrapers) saves birds

[UrbScotty]

http://www.cnn.com/2004/TECH/science/06/11/life.birds.reut/index.html

Turning out the lights of city skyscrapers is helping to save the lives of thousands of birds migrating across North American cities to their spring breeding grounds.

Bird lovers in some cities have been urging owners, managers and tenants of buildings that lie on north-south migration flyways to keep their structures dark at night to reduce the number of birds killed in the spring and fall migration months.

Tall buildings, whose tenants often leave signage and office space brightly lit at night, have long been recognized as a danger to migrating birds. Nobody knows how many perish after being drawn to the light and die from the impact of a collision or from exhaustion, but most estimates are in the tens of thousands in the United States each year.