Skua, Pomarine

Conservation status:

Rare Winter Visitor

Description:

Larger size, heavier build and in adult, elongated broad and twisted central tail-feathers separate it from Arctic. Two phases: all-dark (scarce) and a pale phase, which differs from Arctic in more extensive black cap, darker flanks, blacker breast band (sometimes absent), vent and upperparts. In winter, flanks and tail-coverts barred, elongated tail-feathers often short and always blunt-ended. Juvenile best separated from similar Arctic by more regular bars on flanks, vent, rump and tail-coverts. Whitish base to greater primary-coverts below often conspicuous (frequently absent in Arctic). Bill proportionally larger, heavier at base and more distinctly bi-coloured. With experience, juveniles identified by larger size, slower wing-beats of broader wings and deeper belly; also when present, short, blunt-ended central tail-feathers (pointed in Arctic). Piratical attacks more direct, less agile than Arctic’s, frequently chasing large gulls.