Gadfly petrels of the Pterodroma feae-complex in southwestern Atlantic Ocean, Brazil

The Pterodroma feae complex comprises three cryptically looking gadfly petrels (Cape Verde Pterodroma feae, Desertas Pterodroma deserta, and Zino’s Pterodroma madeira), once regarded as a single species, the Fea’s Petrel, P. feae. Recent research using geolocators to track and understand their movements away from breeding grounds demonstrated that both Zino’s and Desertas Petrels do undergo some long-distance movements. They perform a trans-equatorial migration to remote, previously unknown, wintering grounds, in Brazilian waters off the northeast and southern coast of Brazil during their non-breeding season. However, despite several decades of systematic and intensive beached seabird projects along extensive stretches of the Brazilian coast in these two regions, no specimens of either of these gadfly petrels have been reported. Here, we document two photographic specimen records of gadfly petrels off the Brazilian coast, provide comparative criteria for at sea identification and discuss difficulties to determine species level. First, a heavy-billed male Desertas Petrel was photographed over the continental shelf off the Rio Grande do Sul, southern Brazil, and a second specimen off Espirito Santo, southeastern Brazil, over the Vitoria Seamount, either a Desertas or a Cape Verde Petrel. Apart from Brazilian records based solely on geolocator tracking results, these seem to be the first documented specimen records for Brazil of any species within the feae-group, as well as for the southwestern Atlantic Ocean. Further, these records confirm that Brazilian offshore waters are important non-breeding feeding grounds for the feae-group.