A new storm-petrel species from Chile

Abstract

We describe a new species of storm-petrel, Oceanites pincoyae (Pincoya Storm-Petrel), from the Puerto Montt and Chacao channel area, Chile. The description is based on 1 specimen collected at sea in Seno Reloncavi on 19 February 2011 and 11 other individuals that were caught, examined, and released. The new taxon's foraging ecology and behavioral habits are unique among the southern Oceanitinae, including "mouse-runs" and repeated diving beneath the surface to retrieve food items. Its distinctive appearance includes bold white ulnar bars, extensive white panels to the underwing, and white to the lower belly and vent. Among species of Oceanites, it is unique in showing white outer vanes to the outer two pairs of rectrices. It further differs from all other storm-petrels in having a distinctive juvenile plumage. Morphometrically it is distinct from Oceanites gracilis gracilis (Elliot's Storm-Petrel) and smaller than O. oceananicus chilensis (the Fuegian form of Wilson's Storm-Petrel), ha