Buller's Shearwater vs Hutton's Shearwater

Buller's Shearwater and Hutton's Shearwater can be distinguished by their size and plumage patterns. Buller's is larger with a distinctive black cap and white underparts, while Hutton's is smaller with a more uniform dark upper body and a less contrasting face pattern.

1. Size: Buller's is larger. 2. Plumage: Look for Buller's black cap and white underparts versus Hutton's more uniform dark upperparts. 3. Underwing pattern: Buller's has a bold white underwing with a dark trailing edge. 4. Behavior: Note any association with trawlers, more common in Buller's.

Buller's Shearwater is noticeably larger than Hutton's Shearwater.

Buller's Shearwater has a striking black cap, white underparts, and a bold white underwing with a dark trailing edge. Hutton's Shearwater is more uniformly dark above with a less contrasting face and a more muted underwing pattern.

Both species are pelagic and often seen in mixed flocks, but Buller's Shearwater may associate more frequently with trawlers.

Buller's Shearwater breeds on islets off New Zealand and disperses widely across the Pacific. Hutton's Shearwater breeds in the mountains of New Zealand and is typically found closer to the coast.