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Light pollution is a killer for migratory birds

By Gary Bogue
Monday, October 19th, 2009 at 7:54 am in Birds, Migration.

I just received my latest copy of the “Bird Conservation Tip Sheet” from the American Bird Conservancy (ABC) and there’s a very interesting piece in it about the harmful effects of light pollution on migratory birds. Check this out — I think you’re going to be very surprised.

States & communities tackle light pollution harmful to migratory birds:
Communities are starting to attack the problem of light pollution (, which is harmful to migratory birds, through voluntary programs and also through legislation.

Composite photo by NASA of the U.S. at night (with lights)
usanight_dmsp_big ABC

Inspired by Audubon Minnesota’s voluntary Lights Out program (, the state of Minnesota recently enacted a law requiring all state-owned and leased buildings (totaling more than 5,000) to turn off their lights after midnight during spring and fall migration seasons. ABC is currently working with the San Francisco Board of Supervisors, which is considering an ordinance requiring all commercial buildings to turn off lights after 9 pm, or one hour after the close of regular business.

Detroit Audubon’s Project Safe Passage inspired Michigan Governor Jennifer Granholm to proclaim spring and fall migration periods as Safe Passage Great Lakes Days in Michigan, since 2006. This March, the Michigan House of Representatives passed HR 31, a resolution to encourage the Michigan Department of Natural Resources and the Michigan Public Service Commission to promote Project Safe Passage.

Arizona was the first state to take action to address this problem in 1989. Cities and counties in northern Arizona, which has a significant tourism industry based on astronomy and star gazing, passed the first legislation in the United States to reduce “skyglow.” Chicago started the first voluntary Lights Out project in the United States, spurred by increasing bird mortality caused by the growing number of tall buildings. Now, all tall buildings in the downtown area dim lights for five months each year, saving an estimated 10,000 birds annually, as well as significant amounts of electricity.

“Many people didn’t understand why the birds were dying. Once they learned it was due to the lights, they were happy to help,” said Linda Day Harrison, President of BW Phillips Realty Partners, and a member of the Building Owners and Managers Association of Chicago. Lights Out programs now exist in many cities, including Toronto, Houston, Minneapolis/St. Paul, Indianapolis, and Boston.

Skyglow, also called light waste or light pollution, is light which is carelessly or deliberately emitted upwards from poorly aimed or badly designed lamps. This unnecessary lighting is responsible for an array of problems, including the deaths of thousands of migrating birds each year.

Many bird species migrate at night, orienting to stars and the Earth’s magnetic field. Artificial lights can confuse the migrants, particularly on overcast nights when stars are not visible and birds fly low. Birds in large numbers will circle buildings, towers, and other lighted structures until they collide ( with the structure or each other, or drop from exhaustion. To compound the problem, some lights used to mark towers and bridges for airplane navigation were recently shown to also disrupt birds’ magnetic orientation – a double whammy.

We hope that these examples of communities taking action will inspire similar efforts across the country, until Lights Out is no longer the exception but the rule. The popularity of the Earth Hour anti-global warming campaign raises the possibility that global efforts to save energy could also save millions of birds. For more information, contact Christine Sheppard, ABC,

Anything you can do to help turn out the lights in your area is much appreciated. Thanks for caring. /Gary

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