Pétrel à ailes noires vs Puffin de Buller

The Black-winged Petrel and Buller's Shearwater can be distinguished primarily by their wing patterns and overall coloration. The Black-winged Petrel has a distinctive black band on the upper wings, while Buller's Shearwater displays a more uniform grey upperwing with a striking white underwing. Observing these differences in flight can help in identification.

Look for the black band on the upper wings of the Black-winged Petrel, contrasting with the more uniform grey upperwing of Buller's Shearwater. In flight, Buller's Shearwater's white underwing is a key feature.

Buller's Shearwater is generally larger than the Black-winged Petrel.

Black-winged Petrel features a black band on the upper wings and a pale grey body, whereas Buller's Shearwater has a grey upperwing, white underwing, and a more contrasting black cap.