We report on three aberrantly plumaged White-chinned Petrels Procellaria aequinoctialis from the Brazilian Economic Exclusive Zone in the south-west Atlantic Ocean – the first reports based upon tangible evidence for the region. Two of them showed a low degree of colour aberration (some white around the eyes and on the upper-wing coverts), whereas the third exhibited the highest degree of plumage aberration so far reported for the species: a plumage mostly white with brown freckles on the upper- and under-parts, head and nape. We also commented on problems related to at-sea identification of aberrantly plumaged seabirds.
