The antithesis of confusing northern gulls, Swallow-tailed is stunning and distinctive. Breeding adults are mostly pearly gray with a black head, red eyering, pinkish legs, and a pale-tipped bill with a white spot at the base. In flight, note striking three-toned wing pattern with gray, white, and black. Nonbreeding adults have a white head with thick black mascara around the eye. Juveniles similar to nonbreeding adults but darker above with a scaly pattern and an entirely dark bill. Breeds on the Galapagos Islands; highly pelagic for the rest of the year, found in offshore waters as far south as central Chile. Not likely to be seen from land. Forages for squid at night.