Starting this week, New York City is dimming parts of its skyline to ward off visitors: migratory birds. The Chrysler Building, Rockefeller Center, the Citigroup Center, the Morgan Stanley Building, and the World Financial Center are among the high-rises that will dim or turn off nonessential lights at midnight.
The city's skyscrapers will dimming their lights in September and October, during the peak of the fall migratory season, and in April and May, during the peak of the spring migratory season.
This policy will be the first city-wide effort to protect migratory birds from flying into buildings. The voluntary policy is geared toward buildings over 40 stories tall, as well as lower glass buildings that border the Hudson and East Rivers, which birds use as navigational aides. The combination of glass, tall buildings, and bright light is extremely dangerous for birds, says Daniel Klem, an ornithologist at Muhlenberg College in Allentown, PA. He says that over 100 million birds die each year from crashing into glass on all types of structures.
"Here is the bottom line: Birds just don't see glass," says Professor Klem. "The animals are not able to recognize glass as a barrier and avoid it."
Toronto started a program in 1993 to dim its lights, and Chicago started a voluntary program in 1999 that includes 100 buildings. In Chicago, the Field Museum found an 80-percent reduction in bird deaths when lights were turned off during a 5-year study on a single Chicago Building (McCormick Place).
Environmental groups are working with the construction industry to come up with glass that can be seen by birds, potentially by giving the glass a UV coating.
Most buildings plan to turn off just their exterior lights, but some will also turn off interior lights and ask their tenants to draw the shades. The only buildings expected to opt out are ones that are contractually obligated to keep advertisements lighted, Mr. Spinola says.