NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA's Goddard Space Flight Center

Lights Out

Every spring and fall, billions of birds migrate through the US, mostly under the cover of darkness. This mass movement of birds must contend with a dramatically increasing but still largely unrecognized threat: light pollution.

Every spring and fall, billions of birds migrate through the US, mostly under the cover of darkness. This mass movement of birds must contend with a dramatically increasing but still largely unrecognized threat: light pollution. Light pollution harms birds, but you can help!



Why is Light Pollution Dangerous to Migrating Birds?

Light pollution attracts and disorients migrating birds, confusing and exhausting them as well as making them vulnerable to collisions with buildings, not to mention other urban threats like cats and toxins. An estimated 365 – 988 million birds die in collisions with buildings annually, including a number of species of high conservation concern. The BirdCast team joins a growing international Lights Out efforts already underway, including in over 30 cities in North America, in proposing and implementing one solution that is as simple as flipping a switch. In conjunction with primary measures to make buildings and homes, especially their windows, more bird friendly (check out this comprehensive resource for preventing window collisions) during daylight hours, lights out campaigns offer a critically important opportunity to reduce and to eliminate an enormous contributing source of nocturnal and diurnal hazards. 

Helping Birds Helps People Too

Birds provide:

  • ecosystem services, 
  • act as benchmarks for environmental health, 
  • increase livability, 
  • and connect people of all ages and abilities to the natural world.

You Can Help Keep Birds Safe by Turning Off Lights:

Turn off or dim non-essential lighting during critical migration periods! Turning off lights dramatically reduces hazards from attraction to and disorientation by light, allowing birds to safely proceed with their migratory journeys. And further, Lights Out does more than save birds, it saves energy and money! The Environmental Protection Agency highlights energy as the largest operating expense for commercial buildings. Reducing energy use by shutting off lights for migration season makes environmental sense and fiscal sense. 


Lights Out is a win-win for birds and cities, and the people who love both. By working together toward a dark sky every spring and fall, we will keep birds safely on course and out of harm’s way. Each light matters, and your commitment makes all the difference.

This fall, take the pledge to let us know you’re going Lights Out during critical migration periods to protect wildlife in your area!


Take action using these guidelines:


      • Turn off non-essential lights from 11 PM until 6 AM during critical migration periods.
        • Turn off or dim lobby and atrium lights.
        • Turn off or dim interior home lighting, or draw blinds to prevent light escaping.
        • Turn off decorative landscape lighting.
        • Turn off lights before leaving the home or office.
        • Be sure outside lights are aimed down and well shielded.
        • Install motion sensors on outside lights to minimize use.
        • Prevent daylight collisions with bird friendly products for windows


          • Important Dates:

            Spring Migration Dates

            Full Spring Migration Period: March 1 – June 15
            Texas Critical Spring Peak Migration Period: April 22 – May 12

            Fall Migration Dates

            Full Fall Migration Period: August 15 – November 30
            Texas Critical Fall Peak Migration Period: September 6 – October 29


            Spring migration runs from approximately Mar 1-Jun 15th and fall migration from approximately Aug 15-Nov 30th. Birds can be impacted by light pollution on any night during migration, so going Lights Out the full migration season is optimal. However, where full season commitments are not possible, we predict and highlight critical peak windows each season wherein around 50% of the birds migrating pass through in a few weeks. In our pilot campaign state of Texas, the 2022 peak spring migration window runs from Apr 22nd-May 12th and the peak fall migration window from Sep 6-Oct 29. Learn more about this pilot campaign on our Lights Out Texas page, and more about peak windows on our Background and Resources page. Please contact us with any questions about specific peak windows outside of Texas.


          • Many thanks to all the people, partners, and businesses that have already taken part in protecting our birds with the Lights Out initiative!

            Explore the links below for more information and resources.

More in this section

Need background information or more detailed resources?  Learn more

Have more questions about Lights Out and how to participate? Get in touch!  Learn more

Have questions? Find answers to some that are frequently asked.  Learn more

Learn more about what you can do to help protect birds.  Learn more

Find out when the need for Lights Out is especially high in your area using our Migration Alert tool.   Learn more

Learn more about our current pilot campaign in cities across the state of Texas.  Learn more

Learn the peak migration dates for your city in the contiguous U.S. here!  Learn more