For five nights every October, the island of Corvo in the Portuguese Azores goes completely dark on purpose — and that blackout has helped save tens of thousands of baby seabirds.

  • 30,000+ Cory's shearwater fledglings rescued across the Azores since 2015
  • 6,000 of those saved on Corvo island alone
  • 400 residents take part in the annual blackout
  • 65–75% share of the world's Cory's shearwater breeding population hosted by the Azores

Why the Lights Go Off

Each autumn, young Cory's shearwaters leave their nests on Corvo and head out to sea for the first time, flying at night to avoid predators. The trouble is, artificial light from towns disorients the fledglings, causing them to crash-land instead of reaching open water — a problem reported not just in the Azores but also in Madeira and the Canary Islands.

So since 2019, Corvo's local government, Câmara Municipal do Corvo, has partnered with the Portuguese Society for the Study of Birds (SPEA) to switch off public lighting from 9 p.m. to 4 a.m. during the five most critical nights of the fledging season. This year's blackout ran last week.

"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 in a statement. The municipality has in fact been dimming lights during the critical window since 2017, as part of the wider "SOS Cory's Shearwater" campaign.

Volunteers With Cardboard Boxes

A blackout alone doesn't rescue a disoriented chick already grounded on a road or rooftop. That's where dozens of local volunteers come in, patrolling after dark and gently gathering stranded fledglings — sometimes using nothing more than cardboard boxes — before releasing them safely out to sea.

The commitment runs deep on Corvo: a SPEA survey of 207 islanders found unanimous support for the blackout, a striking consensus for a policy that quite literally turns off the lights on an entire community.

More than 30,000 Cory's shearwater fledglings have been rescued in the Azores since 2015 thanks to the campaign — including roughly 6,000 on Corvo alone, according to a photo essay in The Guardian.

A Model for the Region

The project is part of two larger EU-backed initiatives — Interreg LuMinAves, aimed at mitigating light pollution's impact on seabirds, and Interreg EElabs, focused on sustainable artificial lighting. SPEA hopes other towns across the Azores, Madeira, and the Canary Islands will adopt similar blackout windows.

That hope isn't hypothetical. Madeira Island held its own blackout last Thursday, coordinated by the same SPEA-BirdLife network, to help more young shearwaters reach the sea safely while raising awareness among residents and businesses about unnecessary outdoor lighting.

Other SPEA-BirdLife seabird rescue campaigns are underway across the region and will continue mobilizing volunteers through November 5. For an archipelago that hosts the vast majority of the world's Cory's shearwaters, a few dark nights a year amounts to one of the simplest, cheapest conservation interventions on the books — no fencing, no breeding program, just a flipped switch and a community willing to use it.

The Azores' approach shows how a single, low-cost behavioral change — asking a few hundred people to turn off their porch lights for five nights — can measurably move the needle for an entire species' survival odds, without requiring new infrastructure, funding battles, or years of lead time.