Oscar Dewhurst / Andean gull (Chroicocephalus serranus) in flight. Arequipa, Peru. September

Rick Price / Andean gull (Chroicocephalus serranus) juvenile holding plastic tub in beak, Peru, South America.

Rick Price / Andean gull (Chroicocephalus serranus) juvenile holding plastic tub in beak. Peru, South America.

Lucas Bustamante / Andean Gull (Chroicocephalus serranus) calling in flight, Cotopaxi, Ecuador.

Bernard Castelein / Andean gulls (Larus serranus) two on water, Sajama National Park, altiplano, Bolivia September

Bernard Castelein / Andean gull (Larus serranus) hot springs of Polques, Reserva Eduardo Avaroa, altiplano, Bolivia September

Murray Cooper / Andean Gull (Larus serranus) pair flying, Colombia

Glenn Bartley / Andean Gull (Larus serranus) pair calling, Bolivia

Murray Cooper / Andean Gull (Larus serranus) flying, Ecuador

Mike Read / Andean gull flying {Chroicocephalus serranus} Cotopaxi, Ecuador

Mike Read / Andean gull flying {Larus serranus} Cotopaxi Ecuador

Daniel Heuclin / Andean gull (Chroicocephalus serranus) in flight, El Tatio, Chilean Andes. September.