Scopoli’s shearwater, Calonectris diomedea, in the southwest Atlantic Ocean

Abstract

Knowledge of marine biodiversity has been increased by combining modern and traditional tools that render species identification an accurate process. In addition, understanding the ecological differences between closely related species is critical for effective conservation. Calonectris (Aves: Procellariidae) is a four-species genus of phenotypically similar pelagic seabirds; three of the four species inhabit the Atlantic Ocean. However, this taxonomic splitting has not been completely recognised in the New World, hindering our understanding of species-specific nonbreeding distributions because of misidentification in nonbreeding areas. Here, we have presented the first Scopoli’s shearwater, Calonectris diomedea, in the southwest Atlantic Ocean by using morphometrics, stable isotope analyses, and bill and plumage colouring. Although the southwest Atlantic Ocean is a common nonbreeding area for the sister species, Cory’s shearwater, Calonectris borealis, and Cape Verde shearwater, Calonectris edwardsii, it has been considered a potential nonbreeding area for Scopoli’s shearwater. This study contributes to the separation of Cory’s shearwater from Scopoli’s shearwater and provides a record of the latter in the southwestern Atlantic Ocean, thus contributing to a better understanding of the nonbreeding range of Scopoli’s shearwater in the New World.