The ivory gull has an extremely northern distribution and is probably the northernmost nesting bird species. It breeds either in single pairs or in colonies of up to several hundreds of pairs. The ivory gull is versatile in its choice of nesting ground; it breeds on steep cliffs and nunataks in inland or coastal regions, as well as on flat ground covered with gravel or scanty tundra vegetation. The remote localisation of the breeding colonies may reduce potential predation of eggs and young by predators, such as arctic fox, polar bear and predatory birds (e.g. glaucous gull and skuas). The nest is built of plant material and feathers and is placed either on a narrow cliff ledge or directly on flat ground. The ivory gull lays 1-3 grey-brown or greenish eggs with dark brown speckles. Egg-laying has been reported from mid-June to mid-July. The eggs are incubated by both parents for about 25 days and the young leave the nesting grounds fully fledged at about seven weeks of age.