Little Auk vs Brünnich's Guillemot

In short

The Little Auk (Alle alle) and Brünnich's Guillemot (Uria lomvia) are both members of the Alcidae family, but they differ significantly in size and structure. The Little Auk is much smaller and more compact, while Brünnich's Guillemot is larger with a more elongated body and thicker bill. These structural differences are the most reliable field marks.

Identification tips

1. Size and Structure: Look for the smaller, more compact body of the Little Auk versus the larger, elongated Brünnich's Guillemot. 2. Bill Shape: The Little Auk has a shorter, more conical bill, while Brünnich's Guillemot has a thicker, longer bill. 3. Plumage: Note the darker face and neck of Brünnich's Guillemot during breeding season. 4. Flight Pattern: Little Auks often fly in tight flocks, whereas Brünnich's Guillemots are more solitary or in smaller groups. 5. Habitat: Consider the habitat; Little Auks prefer rocky cliffs, while Brünnich's Guillemots are more associated with sea ice edges.

Size

The Little Auk is notably smaller and more compact compared to the larger and more elongated Brünnich's Guillemot.

Plumage

Both species have black and white plumage, but the Little Auk has a more uniformly black upperparts and white underparts, while Brünnich's Guillemot has a darker face and neck during the breeding season.

Behaviour

Little Auks are more likely to be seen in flocks, often flying in tight formations, whereas Brünnich's Guillemots may be seen in smaller groups or alone, especially when diving.

Habitat

Both species are found in Arctic and sub-Arctic regions, but Little Auks are more often associated with rocky cliffs and islands, while Brünnich's Guillemots are found along sea ice edges and open waters.

Voice

Vocalizations are not a primary distinguishing feature in the field, but Little Auks have a higher-pitched, chattering call compared to the deeper, guttural calls of Brünnich's Guillemot.