Mark Bowler / Belcher's / Peruvian band-tailed gull (Larus belcheri) calling, Paracas National Reserve, Peru

JIM CLARE / Peruvian band-tailed gull, (Larus belcheri) chicks. Punta San Juan, (Reserva Nacional de Islas, Islotes y Puntas Guaneras) Peru.

JIM CLARE / Peruvian band-tailed gull, (Larus belcheri) chicks. Punta San Juan, (Reserva Nacional de Islas, Islotes y Puntas Guaneras) Peru.

Cyril Ruoso / Band-tailed gull (Larus belcheri) in Nazca coastal desert in Paracas National Reserve, Peru

Cyril Ruoso / Band-tailed gull (Larus belcheri) defending nest against Humboldt penguin (Spheniscus humboldti) Punta San Juan, Peru

Cyril Ruoso / Band-tailed gull (Larus belcheri) pair mating on beach, Punta San Juan, Peru

Cyril Ruoso / Band-tailed gull (Larus belcheri) pair mating on beach, Punta San Juan, Peru

Cyril Ruoso / Band-tailed gull (Larus belcheri) with Cormorant egg in beak, guano island of Pescadores, Peru

Cyril Ruoso / Band-tailed gull (Larus belcheri) flying over sea with crab in beack, Nazca coastal desert, Peru

Cyril Ruoso / Band-tailed gulls (Larus belcheri) two standing on a rock, Punta Coles reserve, Peru.

Chris Mattison / Band-tailed gull (Larus belcheri) in non-breeding plumage, Pan de Azucar National Park, Atacama, Chile.

Cyril Ruoso / Band-tailed Gull (Larus belcheri) preying on the egg of a Guanay Cormorant (Phalacrocorax bougainvillii), Isla Pescadores, Peru