Keeping it savage; the Cory’s shearwaters of the Selvagens

The southernmost point of Portugal lies 280 km south of the island of Madeira and boasts a name that reflects both its remote location and demanding climate conditions. The Savage islands or Ilhas Selvagens in Portuguese are a small archipelago consisting of two major islands; Selvagem Grande and Selvagem Pequena that are each surrounded by clusters of reefs and islets. Similar to the other Macaronesian Islands, the islands were created through volcanic forces, in their case between 60-70 million years ago.

The mild subtropical desert climate due to their geographic location as well as the lack of any significant mountain range diminishes the amount of freshwater available on the islands, leading to a scarcity in terrestrial life. This scarcity is, however, not reflected in the marine bird populations nesting across the archipelago and feeding on its abundant marine life. Currently the islands are a home and stopover for Cory’s shearwaters (Calonectris borealis), White-faced storm petrels (Pelagodroma marina), Bulwer’s petrels (Bulgaria bulwerii), North atlantic little shearwater (Puffinus baroli), Madeiran storm petrel (Hydrobates castro) and many others.

The Cory’s presence on the Selvagens are of particular interest to scientists. According to a recent study, the Selvagens islands are home to the largest colony of the species in the Atlantic with over 39,000 pairs confirmed on a single island. This population is apparently consistently growing and, apparently, is the only one that returns to land during the daytime rather than only at night. In 1971 the area was designated a natural reserve, with the Portuguese government recognising its status as an important habitat for Cory’s and the other nesting species. In March 2022, the reserve was expanded from 92 to 2,677 square km, in an area of 12 nautical miles around the islands, in which fishing and any other extractive activity are prohibited, turning it into the largest marine protected area in the North Atlantic.

The birds presence was not always met with the intention for conservation; in the past several Madeiran expeditions took place to the islands to hunt juvenile Cory’s. In fact, reports by naturalist Ernst Schmitz noted that 20–22,000 Cory’s shearwaters were hunted in September or October in the islands at the end of the 19th century.

While the designation of the area has allowed Cory’s pairs to flourish once more, the birds continue to fall victim to human activity. In July 2024, the regional government revealed that it had temporarily authorized the capture of skipjack fish in the reserve for research and monitoring purposes, which conservationists fear could lead to more authorisations in future and have destructive consequences for the surrounding marine life, which inevitably will affect the nesting bird populations. One of the Portuguese political parties, CHEGA, even proposed opening the area to tuna fishing fleets. Thankfully the environmental organization “Zero” created a campaign to oppose this known as the “Zero Project Selvagens”. The campaign has received ample support from local conservationists and we can only hope that it will result in stopping the proposed changes and preserving the beautiful Selvagens islands and their Corys.

By Paula Thake