Arctic Skua vs Common Guillemot

The Arctic Skua (Stercorarius parasiticus) and Common Guillemot (Uria aalge) are distinct in both appearance and behavior, with the skua being a kleptoparasitic seabird and the guillemot a diving auk. The skua exhibits variable plumage morphs, while the guillemot is more uniform with its black and white coloration.

1. Look for the Arctic Skua's variable plumage morphs and contrasting cap and breast band. 2. Observe behavior: skuas chase other birds, while guillemots dive for fish. 3. Note habitat: skuas are more often seen over open water, guillemots on rocky coasts. 4. Listen for vocalizations: skuas have harsh calls, guillemots are more vocal in colonies.

Arctic Skuas are medium-sized seabirds, whereas Common Guillemots are larger and more robust.

Arctic Skuas have variable plumage with dark and light morphs, often showing a contrasting cap and breast band. Common Guillemots are uniformly black above and white below, with no morph variation.

Arctic Skuas are known for their kleptoparasitic behavior, often chasing other birds to steal food. Common Guillemots dive for fish and are not kleptoparasitic.

Arctic Skuas are often found in open seas and coastal areas, particularly in the north Atlantic and Pacific. Common Guillemots prefer rocky cliffs and islands where they breed in colonies.

Arctic Skuas have harsh calls, though not often heard. Common Guillemots produce a variety of calls, especially in breeding colonies.