Leach's Storm-Petrel vs Northern Fulmar

Leach's Storm-Petrel and Northern Fulmar are both seabirds, but they differ greatly in size and flight style. Leach's Storm-Petrel is much smaller with a fluttering flight, while the Northern Fulmar is larger and has a more powerful, gliding flight. Observing these differences in flight and size are the most reliable field marks.

1. Size and Flight: Look for the smaller size and fluttering flight of Leach's Storm-Petrel compared to the larger, gliding Northern Fulmar. 2. Plumage: Note the white rump of Leach's Storm-Petrel, absent in Northern Fulmar. 3. Location: Consider proximity to shore; Northern Fulmar may be closer. 4. Vocalization: Listen for vocalizations near colonies, more common in Northern Fulmar.

Leach's Storm-Petrel is significantly smaller than the Northern Fulmar, which is a robust and bulky bird.

Leach's Storm-Petrel has a dark plumage with a distinctive white rump, whereas Northern Fulmar can appear in light and dark morphs, but lacks the white rump contrast.

Leach's Storm-Petrel exhibits a fluttering, bat-like flight pattern, often appearing erratic. In contrast, Northern Fulmar has a strong, steady flight with long glides.

Both species are pelagic, but Northern Fulmar is more likely to be seen closer to shore, especially during breeding season.

Leach's Storm-Petrel is generally silent at sea, while Northern Fulmar may emit grunts or croaks, especially near breeding colonies.