The first two cases of melanism in Cory's Shearwater Calonectris diomedea

Aberrant colourations have a low frequency of occurrence in vertebrates; however, they are observed in a great number of species (Sage 1962, Pigg 1998, Bried & Haubreux 2000, Watkins-Colwell 2002), including seabirds (e.g. Guerra & Fitzpatrick 1987, Bried & Mougeot 1994, Voisin et al. 2002, J. Bried unpubl. data). In this paper, we report the first observations of melanistic Cory’s Shearwaters Calonectris diomedea.