Today we celebrate the World Migratory Bird Day. Of the ten breeding seabird’s species of the Archipelago, three are known to be remarkable migrants. Cory´s shearwater (Calonectris borealis), which occur in the Azores between February and October, migrate to the South Atlantic during the winter, staying all the time at sea in a extensive area from the coast of Brazil to the coast of South Africa, with some birds able to explore the waters of the Indian ocean1;2. Common and Roseate terns (Sterna hirundo and S. dougallii) stay between September and April on the coast of Brazil or on the southwest coast of the African continent, in the latter place mainly on the beaches of Ghana and the Ivory Coast3;4. These migrations are characterized by two long trips, at the end of the nesting season to the wintering areas and in the month before the start of a new nesting season. For this reason, this day is celebrated twice a year, on the second Saturday of May and October each year (https://eurocid.mne.gov.pt/eventos/dia-mundial-das-aves-migratorias-2021).

Photo credits: Paulo Henrique Silva -SIARAM (Garajaus-rosado/Roseate terns)

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[[1]] González-Solís, J., Croxall, J., Oro, D. & Ruiz, X. 2007. Trans-equatorial migration and mixing in the wintering areas of a pelagic seabird. Front. Ecol. Environ. 5: 297 – 301.

[2] Dias Maria P., Granadeiro José P., Phillips Richard A., Alonso Hany and Catry Paulo 2011Breaking the routine: individual Cory’s shearwaters shift winter destinations between hemispheres and across ocean basins. Proc. R. Soc. B.278:1786–1793

[3] Verónica C. Neves, Cristina P. Nava, Matt Cormons, Esteban Bremer, Gabriel Castresana, Pedro Lima, Severino M. Azevedo Junior, Richard A. Phillips, Maria C. Magalhães & Ricardo S. Santos (2015). Migration routes and non-breeding areas of Common Terns (Sterna hirundo) from the Azores, Emu – Austral Ornithology, 115:2, 158-167

[4] Neves, V.C. 2006. Towards a conservation strategy of roseate tern Sterna dougallii in the Azores. PhD Thesis, University of Glasgow. 305pp.