Océanite tempête vs Océanite de Swinhoe

European Storm-Petrel and Swinhoe's Storm-Petrel are similar in appearance but can be distinguished by subtle differences in structure and behavior. European Storm-Petrels are generally smaller and exhibit different flight patterns compared to the slightly larger Swinhoe's Storm-Petrel.

1. Size: Look for the smaller size of the European Storm-Petrel. 2. Flight Pattern: Observe the flight; European Storm-Petrel has a fluttering flight, whereas Swinhoe's Storm-Petrel tends to have a steadier, more direct flight.

European Storm-Petrel is generally smaller than Swinhoe's Storm-Petrel.

European Storm-Petrel often shows a more fluttering flight pattern, while Swinhoe's Storm-Petrel may appear more direct and steady in flight.