It breeds mainly on the Galapagos Islands and one island off Colombia and when not breeding travels along the off shore waters of South America’s Pacific coast from central Colombia to central Chile. While breeding, both parents remain at the nest during the day, alternating brooding duties. At night the non-brooding parent will take to sea and forage the entire night for squid. This is the most nocturnal gull and its large eyes are specifically adapted for this strategy. In further contrast to almost all other gulls which will return to their natal colony to breed, at the onset of their first breeding cycle Swallow-tailed Gulls will find a new breeding colony.