Grey-headed gull

The grey-headed gull is slightly larger than the black-headed gull at 42 cm length. The summer adult has a pale grey head, a grey body, slightly darker in tone than in black-headed gull, and red bill and legs. The black tips to the primary wing feathers have conspicuous white "mirrors". The underwing is dark grey with black wingtips. The grey hood is lost in winter, leaving just two dark smudges around and behind the eye. The eye is dark in immatures, but has a white iris in adults. The sexes are similar. It takes two years to reach maturity; first year birds have a black terminal tail band, and more dark areas in the wings. In flight, the wings are broader than those of black-headed gull. It is a noisy species, especially at colonies. The call is a raucous crow-like caw, caw. It is locally abundant, breeding in large colonies in reedbeds and marshes; it lays two or three eggs in a nest, which can be on the ground or floating. Like most gulls, it is highly gregarious in winter, both when feeding and in evening roosts. Although it is predominantly coastal or estuarine, it is not a pelagic species, and is rarely seen at sea far from land. Flocks numbering hundreds or thousands can form when the feeding conditions are appropriate. ==Taxonomy==

Currently, two subspecies are accepted: • C. c. cirrocephalus (Vieillot, 1818) – South America • C. c. poiocephalus (Swainson, 1837) – Africa They are scarcely distinguishable, with the South American subspecies slightly larger and paler-backed than the African subspecies, and with a marginally larger white spot ("mirror") on the two outer primaries. if verified, this would require the splitting of the African taxon as a separate species to avoid paraphyly. This has however not yet (as of 2024) been adopted by the IOC World Bird List. Chroicocephalus cirrocephalus, Mejía, Peru 1.jpg|C. c. cirrocephalus in non-breeding plumage, Mejía, Peru Chroicocephalus cirrocephalus, Laguna del Cisne, Canelones, Uruguay 1.jpg|C. c. cirrocephalus in flight in breeding plumage, Uruguay Grey-headed Gull (Chroicocephalus cirrocephalus poiocephalus), Cape Vidal, South Africa.jpg|C. c. poiocephalus at Cape Vidal, South Africa Chroicocephalus cirrocephalus.jpg|C. c. poiocephalus in breeding plumage, Bakau, Gambia Grey-headed Gulls, Lake Elementeita, Kenya (Chroicocephalus cirrocephalus).jpg|C. c. poiocephalus flock, Lake Elementaita, Kenya Chroicocephalus cirrocephalus MHNT.ZOO.2010.11.125.16.jpg|Eggs of C. c. poiocephalus from Banc d'Arguin, Mauritania - MHNT ==References==