Each autumn, the small Portuguese island of Corvo embarks on a remarkable initiative aimed at aiding young seabirds in their journey to the Atlantic Ocean. Nestled in the Azores archipelago and home to around 450 residents, this unique effort involves switching off public streetlights for five nights during the fledging season of Cory’s shearwater chicks. The goal is to prevent these young birds from becoming disoriented and confused by artificial lighting as they make their first flights.
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Cory’s shearwater chicks typically nest for about three months before attempting to take to the skies. They instinctively launch their inaugural flights at night, seeking to evade potential predators. Under normal circumstances, these fledglings rely on natural light sources to guide them towards the ocean. However, man-made illumination can disrupt this instinct, leading the birds into populated areas rather than towards safety.
The consequences of such disorientation can be dire. In many instances, the fledglings collide with buildings or land perilously on roads, exposing them to dangers from vehicles, predators, or dehydration. Once grounded, these inexperienced birds often struggle to regain flight, leaving them vulnerable and in need of rescue.
Recognising the plight of these migratory seabirds, the residents of Corvo initiated rescue efforts in 1991 after witnessing distressing numbers of young shearwaters failing to reach the ocean. Villagers began patrolling their only town, Vila do Corvo, searching for birds that had succumbed to confusion caused by networked lights.
As rescuers find stranded shearwaters, they carefully place the birds in cardboard boxes overnight to allow for recuperation. The following day, these seabirds are released from cliffs overlooking the ocean, giving them another opportunity to make their vital journey.
The local rescue attempt garnered momentum over the years, leading to the establishment of the SOS Cagarro campaign in 1995. This initiative expanded across all nine islands of the Azores, providing a structured way to protect the young shearwaters during their migration.
In a significant move to ameliorate the situation for the fledglings even further, the island’s authorities began turning off public lighting during critical periods of the fledging season in 2017. The initiative has since evolved into an extended blackout lasting multiple nights, aimed specifically at safeguarding young shearwaters in the autumn.
Essentials lights remain on for safety, while residents are also encouraged to reduce unnecessary indoor lighting during this period. The local community wholeheartedly supports these endeavours; a survey conducted by the Portuguese Society for the Study of Birds (SPEA) revealed that every resident who participated approved of the blackout measures.
The broader SOS Cagarro campaign has led to thousands of rescues across the Azores, boasting impressive figures of over 30,000 young Cory’s shearwaters saved since 2015, with around 6,000 of these rescues conducted on Corvo alone. This commendable effort not only reflects the residents’ commitment to wildlife protection but also underscores the potential for communities to come together for a common conservation cause.
Further research into the relationship between artificial lighting and the challenges faced by these seabirds has shown that a staggering 85% of disorientation incidents occurred when streetlights were switched on. While this data does suggest a correlation, it does not quantify the exact reduction of stranded birds attributable to the blackouts themselves.
For the people of Corvo, the practice of extinguishing streetlights has become a significant aspect of their identity, showcasing their dedication to protecting the diverse wildlife that inhabits their island. With ongoing efforts to assist the seabirds in distress, the hope is that fewer fledglings will require rescue, as Corvo’s efforts continue to light the way for future generations of birds taking that crucial first flight towards the sea.
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