Little Auk vs Common Guillemot

In short

The Little Auk (Alle alle) and the Common Guillemot (Uria aalge) are both seabirds from the Alcidae family, but they differ significantly in size and structure. The Little Auk is much smaller with a stubby bill, while the Common Guillemot is larger with a long, slender bill. These differences are most apparent when seen side by side.

Identification tips

1. Size and Structure: Look for the smaller size and stubby bill of the Little Auk compared to the larger, slender-billed Common Guillemot. 2. Plumage: Note the black head and back of the Little Auk, contrasting with the more uniform dark upperparts of the Guillemot. 3. Habitat: Consider the location; Little Auks prefer colder, Arctic waters, while Guillemots are more common along rocky coasts. 4. Vocalization: Listen for the high-pitched twitter of the Little Auk versus the growling calls of the Guillemot.

Size

The Little Auk is significantly smaller than the Common Guillemot, almost half its size.

Plumage

Little Auks have a black head, neck, and upperparts with white underparts, while Common Guillemots have a more uniform dark brown or blackish upperparts and white underparts. In nonbreeding plumage, the Guillemot's face becomes whiter.

Behaviour

Both species are social and often found in large flocks, but Little Auks are more likely to be seen in compact groups, while Guillemots often form dense colonies on cliffs.

Habitat

Little Auks breed in the high Arctic and are often seen in cold waters, whereas Common Guillemots are more widespread and can be found along rocky coasts and cliffs in the North Atlantic.

Voice

Little Auks produce a high-pitched twittering, while Common Guillemots have a variety of calls, including a distinctive 'growling' sound.