Sabine's gull steals eggs from nesting colonies of Arctic terns. The Sabine's gull is a small gull, in length and weighing . The wings are long, thin and pointed with a span of between . The bill, which is black with a yellow tip, is around long. This species is easy to identify through its striking wing pattern. The adult has a pale grey back and wing coverts, black primary flight feathers and white secondaries. The white tail is forked. The male's hood darkens during breeding season. Young birds have a similar tricoloured wing pattern, but the grey is replaced by brown,
Swallow-tailed gull the head moving side to side. This call is contagious, with other birds joining in without seeing the cause. A loud and rapid "kweek, kweek, kweek" is the greeting call between mates, made with the head and neck curved forward to the ground. The swallow-tailed gull breeds from about 5 years old, with pairs frequently staying together from year to year. Most breed throughout the year in mixed colonies on the cliffs of the Galápagos Islands sometimes on flat areas, and food for the young is hunted from the seas near to the nesting colonies. The nest is made on