Lights Out, San Diego! is a campaign to build awareness about how light pollution impacts migrating birds and other wildlife. San Diego is located on the Pacific Flyway and every year during the fall and spring migration seasons, millions of birds fly over San Diego every night.
Through the Lights Out, San Diego! campaign, we encourage everyone to turn off non-essential lighting from the hours of 11 p.m to 6 a.m during the migration season to provide darker skies for these nocturnal migrants. Will you take the Lights Out, San Diego! Pledge?
WHY LIGHTS OUT?
More than 80% of North America’s migrating birds migrate at night, and San Diego is privileged to see so much of this migration. Our beautiful county is on the Pacific Flyway—we are right along the path that many different species of birds use to head south in the fall and come back north in the spring.
Light pollution can disrupt migration as it can cause:
- Disorientation - Birds are drawn to the light
- Exhaustion - Birds can find themselves flying in circles over and over
- Building collisions - From their encounters with brightly lit building
- Delays in migrations - Some birds slow down their flight in brightly-lit cities
- Grounding of seabirds - From landing in light-polluted areas and being unable to fly again.
Researchers have studied the impact of light pollution on many species of birds, like:
WESTERN SNOWY PLOVER
The Western Snowy Plover avoids areas with light pollution, most likely because increased light can make them more visible to predators. Just half the brightness of the moon in a clear sky can disrupt the plovers’ resting sites.
European Curlew were found to take off sooner in the presence of a predator when more artificial light was present. Light pollution has the potential to disrupt predator-prey relationships in all kinds of unknown ways, perhaps even for our own Long-Billed Curlew.
Artificial light has been observed to attract Manx Shearwater fledglings, but repel adults. The potential consequences for fledglings and adults are different, but disastrous; fledglings could become grounded in light polluted areas, while adults could abandon their nesting burrows.
Because light pollution attracts insects, it has been shown to attract insectivorous and omnivorous birds as well, such as the Western Bluebird. As insects are more available in areas of light pollution, it can lead to a decrease in the diversity of what many birds eat.
HOW SERIOUS IS THE PROBLEM?
According to the US State of the Birds report for 2022 nearly 1 in 4 breeding birds have been lost from the US and Canada in the past 50 years. This is a staggering loss of 3 billion birds!
It has been reported that about 365 million to 988 million birds die every year in the US due to collisions with buildings. Of these deaths 56% occur at low-rises (4 to 11 stories) and 44% at residences.
In 2017 in just one night 400 migratory birds were killed by just one skyscraper in Texas.
IMPORTANCE OF SAN DIEGO FOR MIGRATORY BIRDS
BirdCast data from last year’s fall migration shows that nearly 20 million birds flew over San Diego County between the months of August and November 2022!
Spring Migration, which just concluded, saw over 67 million birds fly over our county during the night.
WHAT CAN YOU DO?
Sign up to be a part of Lights Out, San Diego! and help minimize light pollution so we can reduce bird mortality as they fly over San Diego in the coming months!
Fall 2023 Migration Dates
- Full Fall Migration Period: August 1 – November 30
- Critical Fall Peak Migration Period for San Diego: September 1 – November 15
HOW TO GO LIGHTS OUT
STEP 2: Turn off all non-essential lights from 11 pm to 6am during the migration season
- Turn off any decorative/ landscape lighting
- Dim interior lighting and close blinds to make sure no light leaks out
- Turn off lights when leaving home/ office
STEP 3: During migration season report any dead bird sightings using iNaturalist
STEP 4: Spread the word by posting your support on social media using #LightsOutSanDiego
STEP 5: Talk to your Homeowners’ Association / Building Manager / School / Employer to see if you can bring Lights Out, San Diego! to your community!
For essential lights (e.g. security and safety lighting) follow these guidelines from the International Dark Sky Association
- Install motion sensors to minimize outside light use
- Make sure outside lights are aimed down and shielded
- Use warm colors for lighting (<3000 Kelvin)
Simons, A.L.; Martin, K.L.M., and Longcore, T., 2022. Determining the effects of artificial light at night on the distributions of Western Snowy Plovers (Charadrius nivosus nivosus) and California Grunion (Leuresthes tenuis) in southern California. Journal of Coastal Research, 38(2), 302–309. Coconut Creek (Florida), ISSN 0749-0208.
Jolkkonen, J., Gaston, K.J. & Troscianko, J. Artificial lighting affects the landscape of fear in a widely distributed shorebird. Commun Biol 6, 131 (2023). https://doi.org/10.1038/s42003-023-04486-x
Syposz, M., Padget, O., Willis, J. et al. Avoidance of different durations, colours and intensities of artificial light by adult seabirds. Sci Rep 11, 18941 (2021). https://doi.org/10.1038/s41598-021-97986-x
Morelli, F., Tryjanowski, P., Ibáñez-Álamo, J.D. et al. Effects of light and noise pollution on avian communities of European cities are correlated with the species’ diet. Sci Rep 13, 4361 (2023). https://doi.org/10.1038/s41598-023-31337-w
Scott R. Loss, Tom Will, Sara S. Loss, Peter P. Marra "Bird–building collisions in the United States: Estimates of annual mortality and species vulnerability," The Condor, 116(1), 8-23, (2 January 2014)