Wilson’s Storm Petrel
Wilson’s storm petrel is a small seabird of the austral storm petrel. It is one of the most abundant bird species in the world and has a circumpolar distribution mainly in the seas of the southern hemisphere but extending northwards during the summer of the northern hemisphere. The world population has been estimated to be more than 50 million pairs.
Wilson’s storm petrel is a small bird, 16–18.5 cm in length with a 38–42 cm wingspan. It is slightly larger than the European storm petrel and is essentially dark brown in all plumages, except for the white rump and flanks. The feet jut beyond the square ended tail in flight.
The European storm petrel has a very distinct whitish lining to the underwing and a nearly all dark upperwing. Wilson’s storm petrel has a diffuse pale band along the upper wing coverts and lacks the distinctive white underwing lining.The webbing between the toes is yellow with black spots in pre-breeding age individuals.