Townsend's Storm-Petrel vs Wedge-rumped Storm-Petrel

Townsend's Storm-Petrel and Wedge-rumped Storm-Petrel can be challenging to differentiate due to their similar size and plumage. The most reliable field mark is the rump pattern: Wedge-rumped Storm-Petrel has a distinctive white wedge on the rump, while Townsend's lacks this feature. Observing these birds in flight can also help, as their flight patterns may differ slightly.

Look for the white wedge on the rump of the Wedge-rumped Storm-Petrel. Townsend's Storm-Petrel will not show this feature. Observing the birds in flight may provide additional clues, but focus primarily on the rump pattern.

Wedge-rumped Storm-Petrel has a distinctive white wedge on the rump, which is absent in Townsend's Storm-Petrel.