Razorbill vs Brünnich's Guillemot

The Razorbill and Brünnich's Guillemot can be distinguished by their bill shape and plumage patterns. The Razorbill has a thick, blunt bill with a distinct white line, while Brünnich's Guillemot has a longer, thinner bill. In flight, the Razorbill shows more white on the underwing than Brünnich's Guillemot.

1. Bill Shape: Look for the Razorbill's thick, blunt bill with a white line. 2. Underwing Pattern: In flight, Razorbills show more white on the underwing. 3. Habitat: Consider the location; Razorbills are more coastal, while Brünnich's Guillemots are often near ice edges. 4. Flock Composition: If mixed with other species, note that Razorbills often associate with other auks.

Both species are similar in size, but the Razorbill is slightly stockier.

Razorbills have a black head, neck, and upperparts with a white belly and a noticeable white line on the bill. Brünnich's Guillemots have a black head and back with a white belly but lack the white line on the bill. In nonbreeding plumage, both species have similar dark and white contrasts, but the Razorbill's white line remains a key feature.

Both species are diving birds, often seen in flocks. Razorbills tend to be more coastal, while Brünnich's Guillemots are more pelagic.

Razorbills are typically found along rocky coasts and islands in the North Atlantic, while Brünnich's Guillemots prefer more northern, ice-edge habitats.

Vocalizations are not a primary distinguishing feature in the field. Both species have similar harsh calls.