Portuguese Islands Go Dark Each October So Young Seabirds Can Find the Sea

For five nights every late October, the streetlights on Corvo — the smallest inhabited island in Portugal's Azores — go dark from 9 p.m. to 4 a.m. The 400-odd residents are not suffering a power failure. They voted for it.

The reason is a large, graceful seabird called the Cory's shearwater. Every autumn, juvenile shearwaters leave their nests and attempt their first flight toward the open Atlantic — always at night, to avoid predators. Artificial light from towns and coastal developments disorients them. Instead of heading out to sea, the inexperienced birds are drawn toward bright sources, where they collide with buildings, land on roads, and become stranded and vulnerable to traffic. The Azores archipelago hosts between 65 and 75 percent of the entire world's breeding population of the species, according to the Portuguese Society for the Study of Birds (SPEA), making what happens on these islands matter far beyond them.

The Corvo blackout, which has run annually since 2019 in partnership between SPEA and the island's local governing body, the Câmara Municipal do Corvo, is part of the wider SOS Cagarro campaign. Dozens of volunteers fan out each night to collect grounded birds and return them to the sea, sometimes carrying them in cardboard boxes. More than 30,000 Cory's shearwater fledglings have been rescued across the Azores since 2015, according to The Guardian — around 6,000 of them on Corvo alone.

The blackout on Corvo is not a grudging concession. A SPEA survey of 207 Corvo inhabitants found unanimous support for it, according to the organization. "Locals and authorities have increasingly recognized the impact of light pollution on birds and the importance of an energy efficiency policy to protect these species," SPEA said.

SPEA and our partners on these projects hope that other towns and islands throughout the region will follow Corvo's example, turning off the lights at crucial times.— SPEA (Portuguese Society for the Study of Birds)

That hope is already becoming reality. On October 30, Madeira and Porto Santo held what organizers called the Mega Apagão — the Great Switch-Off — a voluntary three-hour campaign from 8 p.m. to 11 p.m. in which residents, businesses, and local authorities were encouraged to turn off non-essential outdoor lighting. Unlike Corvo's full municipal blackout, the Madeira initiative was participatory rather than mandatory: garden lights, decorative façade lighting, and communal building lights were the targets, while essential safety lighting remained on.

Eight municipalities took part, including Funchal, Câmara de Lobos, Santa Cruz, Machico, Santana, Calheta, Porto Moniz, and Porto Santo, according to portugal.fr. Several hospitality businesses joined as well, among them properties operated by the Cardoso Group, Hotel Quinta da Serra, VidaMar, Galomar, INATEL Porto Santo Hotel, and Madeira Airport.

The Madeira campaign is organized under the European LIFE Natura@night project, which addresses light pollution and its effects on biodiversity more broadly. SPEA also promotes a label called Noite com Vida — Night Full of Life — recognizing establishments that take steps to protect nocturnal wildlife.

The fledging season on Madeira generally runs from mid-October until around November 15, meaning the most vulnerable period for young shearwaters continues well beyond the single-night event. SPEA is encouraging coastal hotels and restaurants to reduce decorative floodlighting and avoid directing exterior lights toward cliffs or the sea throughout that window. The organization also flagged a practical consideration as the holiday season approaches: delaying the activation of particularly bright festive lighting until after the critical fledging period could reduce disturbance to the birds.

The Corvo blackout is embedded in two European-funded frameworks — Interreg LuMinAves, which targets the impact of light pollution on seabirds, and Interreg EElabs, which focuses on sustainable use of artificial lighting — giving the island's local practice a broader research and policy context.

Anyone who finds a stranded shearwater in Madeira is advised by SPEA to contact the SOS Vida Selvagem Madeira network at 961 957 545. In the Azores, the SOS Ambiente hotline is 800 292 800. Rescuers advise covering the bird gently with a towel, placing it in a ventilated cardboard box, and keeping it in a quiet, dark space while awaiting professional assistance — without offering food, water, or attempting to launch it into the air.

Why it matters — The Azores host the majority of the world's Cory's shearwater breeding population, and these campaigns show that relatively low-cost, community-backed changes to lighting can meaningfully protect a globally significant species — a model other coastal communities worldwide could adopt.

Reported by goodnewsnetwork.org, theguardian.com, portugal.fr