High Quality Content by WIKIPEDIA articles! The Papuan Harrier (Circus spilonotus spilothorax) is a bird of prey native to New Guinea which belongs to the harrier genus Circus. It is commonly classified as a subspecies of the Eastern Marsh Harrier (Circus spilonotus) of eastern Asia. However it may be a separate species or alternatively a subspecies of the Swamp Harrier (Circus approximans) of Australasia.