The common name of this species is inaccurate, as adult black-headed gulls have a chocolate-brown head in summer (5). In winter, this brown hood retreats and the birds have a largely white head with a dark spot behind the eye (5). Other distinguishing features include the prominent white leading edge of the upper wing, which is visible from a fair distance, the tern-like slender wings and the reddish coloured bill and legs (2). Juveniles are different in appearance to adults; they have ginger-brown coloured upperparts and a yellowish bill with a black tip (2). This is a noisy species during the breeding season, producing a loud kwarr call and a short kwup (6).