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Lights Out Chicago! Turn Off/Down Lights after 11 p.m. March 15-August 15

March 20, 2021


Save Migratory Birds by Reducing Collisions!

Each Spring and Fall, about five million birds (of 250 bird species) migrate through Chicago. The birds are often attracted by building lights and lighted glass areas – with fatal results. With good light reduction practices, fatalities are greatly reduced. By turning off your lights by 11 p.m. during each migration season, you can save birds by reducing collisions.

Tall buildings can save many birds by extinguishing decorative lighting on the upper stories after 11 p.m. each evening and leaving lights off until daylight from March 15 to June 15 for the spring  migration, and again from August 15 to November 15 for the fall migration. Birds migrate throughout these months. Tenants on the upper floors are encouraged to turn out lights or draw blinds after 11 p.m. These recommendations apply to all buildings of 40 or more stories and to buildings of 20 or more stories that are isolated from other buildings.

What You Can Do To Help

  • Buildings should extinguish decorative lighting on the rooftop and upper stories after 11 p.m. every night and leave lights off until daylight. This includes lighting on antennas, logos, clocks and other displays or illuminations.
  • Tenants on the upper floors are encouraged to turn lights off or close drapes or blinds after 11 p.m.
  • Buildings along the lakefront or river with extensive glass exteriors should extinguish as much exterior and interior lighting as possible after 11 p.m. and close drapes or blinds.
  • Dimming or extinguishing lighting in building atriums and lobbies in the pre-dawn hours greatly reduces bird strikes.

Frequently Asked Questions

Why are tall buildings a danger for migrant birds?
It is believed that the lights on tall buildings disrupt the navigation systems of birds unlucky enough to encounter these buildings during migration. Confused, they circle the buildings repeatedly and die from exhaustion or collision.

What kind of birds are they?
Over 250 bird species migrate through Chicago – about 5 million individuals in all. Many birds killed at downtown buildings are small migrants from the tropics – warblers, thrushes, tanagers, hummingbirds and others.

What other hazards do downtown buildings pose for birds?
Reflective and transparent windows are significant causes of bird mortality.  Birds cannot see glass, but are attracted to the trees or sky reflected in the glass or to interior lobby landscaping.

Contact Information

If your building experiences bird strikes or has problem areas, contact Chicago Bird Collision Monitors for solutions and suggestions at 773- 988-1867.

For more information on Lights Out, contact Chicago Audubon Society at 773-539-6793 or Chicago Bird Collision Monitors at 773- 988-1867.  Learn more about bird collisions and light reduction at or