Belcher's Gull

Identificazione

Belcher's gull grows to a length of about 49 centimetres (19 in). The sexes are similar in appearance and in the breeding season, the adult has a white head and very pale grey neck and underparts. The mantle and back are greyish-black and the tail is white with a broad black subterminal band and a white trailing edge. The wing coverts and primaries are black and the secondaries dark grey with white tips. The eye is black, the bill yellow with a distinctive red and black tip, and the legs and feet yellow. Outside the breeding season the head is dark brown with a white ring surrounding the eye. The juvenile is mottled brown and white and attains the adult plumage during its third year. Belcher's gull can be confused with the slightly larger kelp gull (Larus dominicanus), but that species has a small white tip on its otherwise black wing and lacks the black tail band found on Belcher's gull.

Tassonomia

Genere: Larus; famiglia: Laridae; ordine: Charadriiformes.

Nome scientifico

Larus belcheri

Autorità

Vigors, 1829

Ordine

Caradriformi

Famiglia

Laridae

Genere

Larus

Areale e habitat

Belcher's gull is found on the Pacific coast of South America. Its range extends from northern Peru to northern Chile in the area influenced by the Humboldt Current and its habitat includes rocky shores, bays and offshore islands. It ventures several kilometres offshore to forage and also feeds on rocky shores when the tide is out. It is a non-migratory species.

Areale riproduttivo

SA : w coast and islets of South America from n Peru to n Chile

Areale non riproduttivo

some move to coasts of n Ecuador and c Chile

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in aumento.

Tendenza della popolazione

in aumento