Scientific name: Stercorarius parasiticus (Linnaeus, 1758)
Bird group: Skuas
Field characters. 41-46 cm (tail streamers up to 11 cm). About the size of a Common Gull. Usually smaller and less bulky with narrower wings than Pomarine Skua and larger and heavier than Long-tailed Skua, but some overlap in both. Plumage variable in adults, ranging from light to almost uniformly black. Light morph like a light morph Pomarine Skua, showing black cap, brown upperparts, yellowish white underparts, and white wing 'flashes' usually obvious. Tail streamers end in a sharp point. Bill and legs black in adult. Flight graceful, flapping interspersed with long glides, rather falcon-like, especially when chasing other birds. Juvenile barred and difficult to distinguish from Pomarine Skua and Long-tailed Skua (see both species).
Voice. Generally silent at sea. On breeding ground, utters various calls, like a nasal 'skee-eer', 'cack-cack-cack', etc.
Distribution. Quite common, but numbers may vary between years. Outside breeding season mainly found at sea. Winters in southern hemisphere.
Habitat. Breeds on tundra and moorland, both coastal and more inland. Outside breeding season mainly found at sea. Apparently follows flocks of migrating terns.
Food. Chases other seabirds, like terns and gulls, to get their prey (fish) but also eats dead animals. During breeding season, feeds also on invertebrates and berries.