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,
Kumlien's gull Kumlien's gull Kumlien's gull ("Larus glaucoides kumlieni") is a large gull which breeds in the Arctic regions of Canada. It is migratory, wintering from Labrador south to New England and west across the Great Lakes. The species is named after the Swedish-American naturalist Thure Kumlien. It is a regular vagrant in small numbers to Britain and Ireland. It has variably been considered a full species, a subspecies of Thayer's gull, a subspecies of Iceland gull, and a hybrid between the aforementioned species, all of which are considered subspecies of the Iceland gull as of 2017. This taxon breeds colonially or