Marine Wildlife Encyclopedia
Swallow-tailed Gull Creagrus furcatus
Distinguished by its sharply forked tail, this South American gull is atypical in feeding at night. It eats squid and fish, spotting them with its large eyes, which are surrounded by distinctive red rings and angled forward to give a wide field of binocular vision. Swallow-tailed gulls nest on islands and disperse far out to sea during the rest of the year.