 The traditional name of Manowar Island is "Delmerriya" or "Wudma"; that of Rocky Island is "Kalamburriya".The islands have been identified by BirdLife International as an Important Bird Area (IBA) because they support over 1% of the world populations of brown boobies (up to 12,000 breeding pairs) and lesser frigatebirds (up to 7700 breeding pairs).Large numbers of Australian pelicans and smaller numbers of eastern reef egrets, ospreys and white-bellied sea-eagles also breed on the islands.