Short-tailed Shearwater vs Heinroth's Shearwater

In short

The Short-tailed Shearwater and Heinroth's Shearwater can be distinguished primarily by their size and plumage. Short-tailed Shearwaters are larger with uniform dark plumage, while Heinroth's Shearwaters are smaller and show more variation in plumage, ranging from dark to pale morphs.

Identification tips

1. Size: Use binoculars to gauge size; Short-tailed is noticeably larger. 2. Plumage: Look for uniform dark brown in Short-tailed versus variable morphs in Heinroth's. 3. Behavior: Note flocking behavior; Heinroth's may be with Black Noddies. 4. Location: Consider geographic location; Heinroth's is more restricted to specific islands.

Size

Short-tailed Shearwater is larger and more robust compared to the smaller Heinroth's Shearwater.

Plumage

Short-tailed Shearwater has a uniform dark brown plumage, while Heinroth's Shearwater exhibits polymorphic plumage with dark, intermediate, and pale morphs.

Behaviour

Heinroth's Shearwater often associates with Black Noddies and feeds in flocks, whereas Short-tailed Shearwater is typically seen in large migratory flocks.

Habitat

Short-tailed Shearwater is often found in open ocean environments during migration, while Heinroth's Shearwater is more localized around New Georgia and nearby islands.