Wilson's Storm-Petrel vs Band-rumped Storm-Petrel

In short

Wilson's Storm-Petrel and Band-rumped Storm-Petrel can be distinguished by their wing and tail structure. Wilson's has shorter, rounded wings and legs that extend beyond the tail, while Band-rumped features longer, pointed wings and a notched tail. Observing flight patterns and leg projection is key.

Identification tips

• Wing Shape: Wilson's has shorter, rounded wings; Band-rumped has longer, pointed wings.
• Tail Shape: Wilson's has a square tail with legs extending beyond; Band-rumped has a notched tail with legs not extending beyond.
• Flight Pattern: Wilson's often 'walks' on water; Band-rumped glides more frequently.
• Plumage: Look for Wilson's underwing bar, which is absent in Band-rumped.

Size

Both species are small storm-petrels, but Band-rumped Storm-Petrel generally appears slightly larger due to its longer wings.

Plumage

Wilson's Storm-Petrel has a dark plumage with a distinctive white rump and underwing bar, while Band-rumped Storm-Petrel also has a white rump but lacks the prominent underwing bar.

Behaviour

Wilson's Storm-Petrel often 'walks' on water with its feet, a behavior less common in Band-rumped, which tends to glide more.

Habitat

Wilson's is a generalist found in both hemispheres, while Band-rumped is more restricted to the Northern Hemisphere and breeds on remote islands.

Voice

Vocalizations are rarely heard at sea and not a reliable field mark for these species.