Cats and Birds information on net.

Until the Hancock Center started turning off its trademark bank of lights during bird migrations, up to 1,500 birds a night would die when they crashed into the skyscraper.

The Hancock has been dousing its ornamental lighting during spring and fall since the early 1980s, and four other downtown buildings have followed suit. But now the city and birding groups are planning to recruit other buildings.

Working at night, they're compiling a list in an effort to douse or dim nonessential lighting. "We're surveying every Loop building," said Suzanne Malec, deputy commissioner of the city's Department of Environment.

To birds flying north or south alongside the lake, city lights "are brighter than anything else on the horizon," said Jerry Garden, president of the Chicago Audubon Society. "And it's the brightness that draws the birds."

They apparently orient themselves by light and sometimes mistake artificial lighting for stars or the moon.

The ones that sing the sweetest are most at risk.

An amateur pilot, Garden has noticed that great blue herons, terns and other varieties cruise at 1,500 feet or higher, safely above skyscraper height. "But songbirds fly at anything from the ground up to 1,000 feet," he said.

Nobody knows how many confused birds fly into lighted buildings. But the Fatal Light Awareness Program of Toronto estimates that at least 100 million birds are killed each year by manmade structures.

On Oct. 7, 1954, 50,000 birds died when they followed the beam of a guide light at Warner Robins Air Force Base in Georgia-right into the ground.

Besides urging that buildings use only minimal lighting during migration times, bird groups encourage homeowners to put bells on their cats or keep them indoors, put in native plants to provide habitat, and reduce use of pesticides or herbicides.

This is the first fall that 311 S. Wacker has turned off lights topping the distinctive superstructure. The lights earned it the nickname of the "birthday cake building." Chicago's fourth tallest edifice at 65 stories, 311 S. Wacker won't switch its rooftop illumination back on until mid-October.

"It's not good for our publicity, but it's the right thing to do," said the building's general manager, Roy Endsley.

# posted by Medical Information : 3:08 AM