Tui De Roy / Swallow-tailed gull (Creagrus furcatus) Plazas Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) calling, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) in flight, Genovesa Island, Galapagos

Mike Read / Swallow tailed gull in flight {Creagrus furcatus} Galapagos

John Shaw / Swallowtail gull (Creagrus furcatus) flying with pebble in its beak, Genovesa Island, Galapagos, May.

Nick Hawkins / Swallow-tailed gull (Creagrus furcatus) perched on volcanic rock. San Cristobal Island, Galapagos.

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) pair mating, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) pair in courtship, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) on water, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) pair, with one preening, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) pair during courtship, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) Plazas Island, Galapagos