Borrego Sun - Since 1949

By Nancy McRae
Borrego Springs Dark Sky Coalition Member 

Keeping It Dark for the Birds


Last updated 5/11/2023 at 11:54am

Most birds migrate at night. In this composite photo, a flock of sandpipers flies close to the horizon against a full moon. Dispersed songbirds wing by high in the sky, just random blips against the stars. Now researchers can hear them as they travel./ Photos Courtesy of Frans Lanting, Audubon Society

Borrego Springs is in the middle of the Swainson's Hawk migration season. Migrating Swainson's are a joy to behold. They kettle up on a helpful air current, set their wings and take off like a battalion of RAF planes to northern climes. It's spectacular sight and we're lucky to be able to witness it because these birds migrate during the day. The vast majority of migratory birds fly at night.

According to the Audubon Society "somewhere between the treetops and the cloud bottoms, one of the least-known, albeit massive in scale, natural phenomena is under way: the nocturnal migration of birds. On any given night in the spring and fall, hundreds of thousands – and at times millions – of birds migrate across North America. From large herons to warblers to vireos, sparrows, and other smaller species, blankets of birds flow across the continent."

This is worth pondering for a moment. While you are snug under the blankets of your bed, tens of thousands of birds may be flying over your home. This largely unseen migration is like an alternate universe, happening all around us and we're not even conscious of it.

Why would birds fly at night? For one thing, they can more easily avoid predators like hawks and other raptors. Many of these predators are inactive at night. Also, the air is generally calmer at night. Anyone who has experienced Borrego's occasional high winds can appreciate the value of a gentle breeze for flight rather than gusts over 100 mph. And, like many humans, birds prefer to travel when it's cooler. The difference is, a bird can't turn on the car air conditioner, so it relies on cooler night time temps.

Most amazingly, however, is that birds navigate using the stars and moon. Studies have shown that many species learn a north-south orientation from a rotational star pattern. And even a thin sliver of moon can light their way. But excessive artificial light at night (ALAN) can lead to disorientation and death for these intrepid little travelers.

Bright lights at night on large buildings attract birds in the same way that bright porch lights attract moths, which can result in fatal collisions. One group of scientists recently reported that "flying birds can see a city on the horizon up to several hundred kilometers away. Essentially, there is no place in the northeastern United States where they can't see the sky glow of a city." FLAP, the Fatal Light Awareness Program, and similar efforts are being made to encourage and/or mandate that office buildings turn off their lights at night. Back when energy was cheap, office buildings were thought to look pretty and impressive with lights left on at night. Now we know that that wasted energy also leads to wasted lives, estimates as high as millions of birds annually. It has been shown that turning off office building lights during the spring and fall migratory seasons can cut these deaths by sixty percent or more.

Last year, Gov. Gavin Newsom vetoed a bill, despite its bipartisan support, that would have dimmed the light pollution emanating from state buildings, saying that it was too costly for California. Introduced by Assemblyman Alex Lee (D-San Jose), AB 2382 would have required all outdoor lights installed after Jan. 1 on properties owned, leased or managed by the state to have light pollution shields, motion sensors and/or automatic dimming or shut-off functions. "This bill would have protected our night skies and migratory species, while reducing wasteful and unnecessary electricity consumption," said Lee, who called the veto "extremely disappointing."

Lee has repackaged the bill, AB 38, again with bipartisan support. If passed, California would follow the footsteps of 19 other states – including Arizona, Texas and New York – that have authorized "dark skies" legislation for energy conservation, human health and saving millions of migrating birds from unnecessary death. You can help: Let your State Assembly representative, Marie Waldron, know you support this bill Here is a link to her website:

You can also let SDGE/Sempra Energy know that you object to them leaving on all the lights in their office buildings at night.

You may be thinking to yourself, we don't have any skyscrapers in Borrego Springs so we don't have to worry about the migrating birds. Not so. There are some easy things you can do to keep night migrations safe for our feathered friends.

The World Migratory Bird Day association (WMBD) gives these recommendations:

1. Reduce the amount of light outside your home or place of business. Turn off all non-essential nighttime lights. For essential lights, use timers or motion detectors to keep usage to a minimum. And always use the minimum wattage necessary for the task at hand. This saves energy and money, too!

2. Change the color of your lights from cool to warm. Studies suggest that green and blue light (often these are LED lights) attracts more birds than red, orange, or yellow light. Use non-LED light bulbs that emit warm lighting to minimize disturbance to birds. Light color is measured in kelvins – the lower the number, the warmer the light.

3. Direct all lighting downward. Place lights to illuminate the floor or ground and use lighting shields to prevent shining into the sky.

4. Advocate for bird-friendly lighting in your town. This could range from talking with your neighbors about the importance of turning off lights to sending that email in support of AB 38 to State Assembly representative Marie Waldron.

5. Become a community scientist. Measure your night sky brightness and submit your observations to the Globe at Night program at or to The Borrego Springs Dark Sky Coalition, which currently has two light monitors in town in addition to light monitors at the Anza-Borrego Desert State Park, to keep tabs on Borrego's dark skies.

Remember, keeping it dark is for the birds.