sentences:  Coastlines and intertidal zones of subantarctic islands, especially around seabird and seal colonies, as well as the vicinity of human habitation.Sheathbills are opportunistic omnivores, predators and scavengers, feeding on strandline debris, algae and other vegetation, as well as on invertebrates, fish, seabird eggs and chicks, seal milk, blood, placentas, carrion, faeces, rodents and human refuse.Loud, high-pitched, strident and staccato calls.