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Providing evidence to improve practice

Individual study: Numbers and population trends of Cory's shearwater Calonectris diomedea at Selvagem Grande, northeast Atlantic

Published source details

Granadeiro J.P., Dias M.P., Rebelo R., Santos C.D. & Catry P. (2006) Numbers and population trends of Cory's shearwater Calonectris diomedea at Selvagem Grande, northeast Atlantic. Waterbirds, 29, 56-60


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Increase ‘on-the-ground’ protection to reduce unsustainable levels of exploitation Bird Conservation

A before-and-after study on Selvagem Grande, Madeira, Portugal (Granadeiro et al. 2006), found that the population of Cory’s shearwaters Calonectris diomedea borealis increased from approximately 7,000 pairs in 1980 and only 64 chicks on the island in 1976, to 18,100 breeding pairs in 1995 (a 5% annual increase) following the installation of a permanent warden and stricter de facto protection on the island. Before this, a series of severe harvesting events by Portuguese and Spanish fishermen in 1975-6 had reduced the population from 130,000-150,000 in the early 1900s, despite the de jure protection of the island from 1971. Despite a 13% decrease over 1995-8, the population was estimated at 29,540 pairs in 2005.