The Hartlaub's gull (Chroicocephalus hartlaubii), also colloquially known as the king gull, is a small, nimble seabird with a length of 36–38 cm. Its plumage is predominantly white, complemented by a grey back and upperwings. The wingtips are black, adorned with striking white "mirrors." A notable feature is its dark red bill and legs. During the breeding season, it sports a very faint lavender grey hood, while outside of this period, its head remains plain white.
Both sexes exhibit similar markings. The Hartlaub's gull is distinguishable from the slightly larger grey-headed gull by its thinner, darker bill, deeper red legs, paler head, and dark eyes. It reaches full maturity in two years, and juveniles can be identified by a brown band across the wings, lacking a black terminal tail band and presenting less dark areas in the wings compared to their grey-headed counterparts.
The gull is a non-migratory breeding resident endemic to the Atlantic Ocean coastline of South Africa and Namibia. Although it is predominantly coastal or estuarine, it is not a pelagic species, and is rarely seen at sea far from land. About one half of the total population, currently estimated at 30,000 birds, lives within the Greater Cape Town area. It has accommodated well to humans, and can become very tame around habitations. Although it is a relatively rare species, about the tenth rarest of the world's 50 or so gull species, it is common in its range and is widely regarded in Cape Town as a nuisance, fouling buildings and bathing in urban ponds. It has, at times, been a hazard to aircraft near airports.
Like most gulls, Hartlaub's is highly gregarious in winter, both when feeding or in evening roosts. This is a noisy species, especially at colonies. The call is a raucous crow-like kaaarrh. This species is frequently the subject of complaints about the noise it makes in urban areas.
