Arctic Skua vs Pomarine Skua

In short

Arctic Skua and Pomarine Skua can be challenging to differentiate due to their similar size and plumage variations. The most reliable field mark is the tail: Arctic Skua typically has pointed central tail feathers, while Pomarine Skua has spoon-shaped tail projections. Both species exhibit dark and light morphs, but Pomarine Skua's dark morph is less common.

Identification tips

• Tail shape: Arctic Skua has pointed central tail feathers; Pomarine Skua has spoon-shaped tail projections.
• Morph frequency: Dark morphs are rare in Pomarine Skua.
• Behavior: Look for kleptoparasitic behavior, more common in Arctic Skua.
• Size and bulk: Pomarine Skua is slightly bulkier.
• Location: Consider the geographic location and season, as their ranges overlap but may differ in specific areas.

Size

Both species are similar in size, but Pomarine Skua tends to be slightly bulkier.

Plumage

Both have dark and light morphs. Pomarine Skua's dark morph is rare, occurring in less than 15% of individuals. Arctic Skua's morphs vary more with latitude.

Behaviour

Both species engage in kleptoparasitism, but Arctic Skua is more frequently observed in this behavior, especially in the northeast Atlantic.

Habitat

Both species breed in Arctic regions but may be found in different areas during migration and wintering, with Pomarine Skua sometimes being more pelagic.