Let there be Night: How light pollution harms migrating birds

Let there be Night: How light pollution harms migrating birds
Alison Robey

If last month’s solar eclipse taught me anything, it’s that we all still love seeing cool stuff in the sky. I don’t think we realize how fast astronomical wonders are fading out of sight: studies show that our night skies grow about 10% brighter every year, and the number of visible stars plummets as a result. At this rate, someone born 18 years ago to a sky with 250 visible stars would now find only 100 remaining.

Vanishing stars may feel like just a poetic tragedy, but as I crouch over yet another dead Wood Thrush on my morning commute, the consequences of light pollution feel very real. Wincing, I snap a photo of the tawny feathers splayed around his broken neck on the asphalt.

It’s not the only such photo I’ll take this year. The building whose towering windows took this thrush’s life is infamous; like many other passersby, I pay close attention to the ground around such spots to record any victims. We upload our morbid photography to iNaturalist, an app usually reserved for more cheerful records and identifications of flora and fauna, where they automatically join several citizen science projects focused on bird-window collisions.

Why the macabre gallery? These collections provide concrete evidence of just how many birds windows kill. Ideally, that information encourages tactics to reduce casualties, like lobbying homeowners and institutions to add decals or screens to their glass.

Though such measures are critical for limiting window strikes during the day, we often overlook the damage our windows cause at night. Remarkably, most bird migration actually occurs by moonlight; if you stand under the stars and listen during migration — which began in earnest last week — an audible chorus of chirps and buzzes overhead indicates a sky full of birds.

Birds evolved to fly under the cover of darkness for many reasons. Nightly travel means they can spend the bright, bug-filled days gathering food. Darkness helps migrants avoid predators, and the lower turbulence and cooler temperatures of nighttime skies allows for more energetically efficient flights.

Though the specifics of nocturnal navigation are a longstanding ornithological mystery, that navigation is undoubtedly disrupted by the growing brightness of the night sky. Bright lights disorient the birds’ sense of direction and attract them towards the light sources themselves. In that state of confusion, nocturnal window strikes skyrocket.

In the U.S., one billion birds die each year by flying into windows. Distinct behavioral changes around brightly lit structures are the main cause of mortality: the usual conversation of nocturnal flight calls grows into a confused cacophony. Those that avoid collisions face different risks: the energy they waste investigating unfamiliar lights means they’ll have a harder time avoiding predators, catching enough food, and reaching their final destinations.

The harm caused by light pollution is not limited to birds. Even in rural areas, many nocturnal animals struggle to adapt to brightening nighttime environments: bats can’t fly efficiently, amphibians can’t reproduce normally, and insects can’t forage effectively.

Humans aren’t immune either. Brighter nights disrupt our sleep cycles — something I can personally attest to, as someone who grew up in Kent and now struggles nightly with the brightness of New Haven — and are associated with a slew of negative health effects. And though people widely associate more lights with greater safety, evidence of this is mixed.

Despite the repercussions, the reach and severity of light pollution keeps growing. Electricity usage in the U.S. is on the rise again; while much of that energy has more intensive uses, the U.S. Energy Information Administration estimates that 6% of residential and 17% of commercial energy is all for lighting.

As disheartened as I am by increasing energy usage and vanishing stars, by unnecessary lights glaring from empty sports fields or barren storage facilities, and by dead songbirds on my morning commute, there is a silver lining to this story. Fixing most pollution problems — microplastics, oil spills, atmospheric CO2 — requires complex, intractable solutions. Light pollution, on the other hand, is completely, immediately, effectively reversible.

This is a critical time of year to make that change. The transition from April to May brings spring rains, bursting tree buds, and a deluge of migrating birds: cheerful songs of Yellow Warblers, gleaming feathers of Scarlet Tanagers, playful flights of American Redstarts. You can watch these migrants gather above your home like a rising storm using BirdCast, Cornell Lab of Ornithology’s avian version of a weather radar.

The closer that storm comes, the more important it is to flip those light switches off. Simple steps, like limiting the use of aesthetic lighting, keeping the beams of necessary lights targeted, dim, and warmly colored, or curtaining bright windows, make all the difference to our birds. Participating in darkening the skies this spring will help keep these little travelers aloft — and maybe bring some stars back into view, too.

Alison Robey is a writer for the Kent Land Trust, a volunteer at the Sharon Audubon Center, and a third-year PhD candidate in Ecology & Evolutionary Biology at Yale University.

Latest News

Remembering George and Anne Phillips’ Edgewood restaurant in Amenia

The Edgewood Restaurant, a beloved Amenia roadside restaurant run by George and Anne Phillips, pictured during its peak years in the 1950s and ’60s.

Provided

With the recent death of George Phillips at 100, locals are remembering the Edgewood Restaurant, the Amenia supper club he and his wife, Anne Phillips, owned and operated together for more than two decades.

At the Edgewood, there were Delmonico steaks George carved in the basement, lobster tails from an infrared cooker, local trout from the stream outside the door, and a folded paper cup of butter, with heaping bowls of family-style potatoes and vegetables, plus a shot glass of crème de menthe to calm the stomach when the modest check arrived after dessert.

Keep ReadingShow less
Artist Alissa DeGregorio brings her work to Roxbury and New Milford

Alissa DeGregorio, a New Milford -based artist and designer, has pieces on display at Mine Hill Distillery.

Agnes Fohn
When I’m designing a book, I’m also the bridge between artist and author, the final step that pulls everything together.
— Alissa DeGregorio

A visit to Alissa DeGregorio Art, the website of the artist and designer, reveals the multiple talents she possesses.

Tabs for design, commissions, print club, and classes still reveal only part of her work.On the design page are examples of graphic and book design, including book covers illustrated by DeGregorio, along with samples of licensed products such as coloring pages and lunch boxes, and examples of prop design she has done for film.

Keep ReadingShow less

Agnes Martin at Dia:Beacon

Agnes Martin at Dia:Beacon

Minimalist works by Agnes Martin on display at Dia:Beacon.

D.H. Callahan

At Dia:Beacon, simplicity commands attention.

On Saturday, April 4, the venerated modern art museum — located at 3 Beekman St. in Beacon, NY — opened an exhibition of works by the middle- to late-20th-century minimalist artist Agnes Martin.

Keep ReadingShow less
google preferred source

Want more of our stories on Google? Click here to make us a Preferred Source.

Falls Village exhibit honors life and work of Priscilla Belcher

Hunt Library in Falls Village will present a commemorative show of paintings and etchings by the late Priscilla Belcher of Falls Village.

Lydia Downs

Priscilla Belcher, a Canaan resident who was known for her community involvement and willingness to speak out, will be featured in a posthumous exhibition at the ArtWall at the Hunt Library from April 25 through May 15.

An opening reception will be held from 5 to 7 p.m. on April 25. The show will commemorate her life and work and will include watercolors and etchings. Belcher died in November 2025 at the age of 95.

Keep ReadingShow less
Crescendo’s 'Stepping Into Song' blends Jewish, Argentine traditions

The sounds of Argentine tango and Jewish folk traditions will collide in a rare cross-cultural performance April 25 and 26, when Berkshire’s Crescendo presents the choral program “Stepping Into Song.”

Christine Gevert, Crescendo’s founding artistic director, described the concert as “a world-class, diverse cultural experience” pairing “A Jewish Cantata” with Martin Palmeri’s “Misa a Buenos Aires.”

Keep ReadingShow less
Salisbury Rotary brings Derby race-day flair to Noble Horizons for community fundraiser
Salisbury Rotary Club President Bill Pond and his wife, Beth, dressed for the occasion during last year’s Kentucky Derby Social.
Provided

SALISBURY — As millions tune in to the Kentucky Derby at Churchill Downs on May 2, a spirited local tradition unfolds in Salisbury, where the pageantry, fashion and excitement of race day are recreated — with a community purpose.

For the past six years in the Community Room at Noble Horizons, all eyes turn to the big screen as the crowd settles in, drinks in hand and anticipation building. Women in elaborate Derby hats — bursting with oversized silk flowers, feathers and playful cutouts — mingle with men dressed for the occasion in crisp jackets and bow ties, fedoras and the occasional red rose on a lapel.

Keep ReadingShow less
google preferred source

Want more of our stories on Google? Click here to make us a Preferred Source.

google preferred source

Want more of our stories on Google? Click here to make us a Preferred Source.