Up until recently the Galapagos Petrel was considered conspecific with the Hawaiian Petrel (Pterodroma sandwichensis) and known as the Dark-rumped Petrel. Differences in morphometrics, breeding timetable, voice and eventually molecular data led to this separation. At first field identification of these two species was considered impossible although recently subtle differences have been identified which suggests that field identification is not only possible but reliable. The Galapagos Petrel breeds on various larger islands in the Galapagos Archipelago. During visits to the Galapagos it is common to see this petrel during deeper water crossings between islands. However, Galapagos Petrels congregate near the shore of breeding islands in the evening and may be readily seen close to land, or even flying to and from nesting sites to the see – even over busy Puerto Ayora on Santa Cruz Island.