Corvo at night: dark skies, stargazing and the shearwater lights-out

Most visitors see Corvo between the morning boat and the afternoon one, and they leave before dark. If you stay the night, you can see one of the darkest skies in Portugal, over a village of about 500 people that switches off its street lights for a few nights each autumn so that young seabirds can find the sea. This guide covers where to look, when the lights go out, what to do if a shearwater lands at your feet, and what the weather means for all of it.

Corvo is small, far out in the Atlantic and lightly lit. In July 2021 the Interreg EELabs project installed ten light meters on the island to measure how dark the night is and how artificial light reaches the seabird colonies. The Canary Islands astrophysicist who coordinated it said the interior of the island has almost no light pollution, and that Corvo may be one of the few places where scientists can measure the natural darkness of the night sky.

The village's old street lights were replaced by warm LEDs (3000 K, which can be turned down to 2700 K) that point at the ground, have no glass cover and can be dimmed by up to 75% in the season when the birds are most at risk. The Instituto de Astrofísica e Ciências do Espaço, Portugal's institute for astrophysics and space sciences, lists the Caldeirão do Corvo among the best places in the country to watch the night sky.

A day trip cannot show you any of this. In Atlânticoline's 2026 timetable, from mid-October to the end of December, the boat from Flores sails only on Tuesdays and Saturdays and leaves Corvo at 16:00 for the return. To be on the island after dark you need a bed or a flight out the next day, and in autumn the beds go early to birders. Our overnight guide covers the hotel, the rental houses and the campsite.

From the village, walk to the edge of the houses and the airstrip, and give your eyes twenty minutes to adjust. The few lights in Vila do Corvo are dim and point down, so a short walk is enough.

The Caldeirão is the site the astronomers name. It is about 10 minutes up the road by minivan, or 6.1 km and some 550 metres of climbing on foot, about an hour and three quarters. We found no published evening van service, so ask your host whether a driver will take you up and wait, and agree the price before you go. If you walk, stay on the road. The crater rim is steep, the trail inside it is wet and boggy, and the lakes can rise over the path, so it is no place to wander in the dark. Take a head torch with a red setting and keep it pointed at the ground.

The municipality describes Corvo as humid, foggy on high ground and windy, with 1,000 to 1,500 mm of rain a year, most of it in autumn and winter. The Caldeirão sits in cloud on many nights, so a clear sky is far from guaranteed. Plan a stay of two or three nights if the stars matter to you, look up every evening, and go to the crater only on a night when you can see its rim from the village. A bright moon washes out the fainter stars, so check the moon phase when you choose your dates.

Corvo has 6,000 to 10,000 pairs of Cory's shearwaters, the cagarro of the Azores, by a 2012 estimate. Their chicks leave the nest at night in October and November. On their first flight they are drawn to light, and street lights pull them inland, where they hit walls and power lines or end up on the ground, at the mercy of cats, dogs and cars. SPEA, the Portuguese bird conservation society, estimates that about 1,100 seabirds die from light pollution in Macaronesia every year.

So for a few weeks each autumn Corvo turns its public lighting off. SPEA and the municipality set the dates every year around the peak of the fledging:

• 2022: from 21:00 between 24 and 30 October, and from 01:00 on the nights either side, 21 to 23 October and 31 October to 10 November.
• 2023: from 21:00, 28 October to 2 November.
• 2024: from 21:00, 27 to 31 October, then from midnight, 1 to 9 November.

We found no published dates for 2025 or 2026. If you are on the island in late October, ask at your accommodation or at the town hall, and expect the village to be properly dark for at least part of your stay. The blackout is the best chance you will get to see the Milky Way from the village itself.

The island has also used its lights for research. In August 2022 it switched them off on alternate nights between 1 and 12 August, while researchers tracked 42 adult shearwaters to see whether the light changed how often they flew in to feed their chicks.

The Azores-wide SOS Cagarro campaign has run since 1995, in 2025 from 15 October to 15 November. In 2024 a support group of 14 volunteers worked on Corvo for the season, together with the island's children and young people.

If you find one:

• Cover its head with a towel, scarf or jumper and wrap it gently.
• Put it in a box with air holes and close it.
• Call the free SOS line, 800 292 800 (as published for the campaign in 2019; check the number locally), or hand the bird to the police or a nature warden.

Do not hold it by the wings or try to throw it into the air. The bird should go back to sea in daylight and on a calm sea, and the wardens release the birds they collect the next morning.

The protected coast and crater zone covers about 45% of the island. Besides the seabirds it shelters two bats, the Azores noctule, found only in the archipelago, and the Madeira pipistrelle. The LIFE Natura@night project measured light pollution there and sampled insects and bats to see how artificial light affects them, which is one more reason to keep your torch dim and pointed down.

Is Corvo good for stargazing? Yes, when the sky is clear. Scientists measuring it since 2021 describe the island's interior as almost free of light pollution, and Portugal's astrophysics institute lists the Caldeirão among the country's best sites. Cloud is the problem, so allow several nights.

When does Corvo switch off its street lights? In late October and early November, for the shearwater fledging. The dates change every year: 27 October to 9 November in 2024. Ask locally for the current year.

Can I see the stars on a day trip from Flores? No. The boat leaves Corvo at 16:00 in the 2026 autumn timetable, so you need to stay overnight.

What do I do if I find a young shearwater on the ground? Cover it with a cloth, put it in a ventilated box and call the SOS line, 800 292 800, or give it to the police or a nature warden. Never throw it into the air.