The Papuan harrier (Circus spilothorax) is a captivating bird of prey, a resident of New Guinea's skies. It is a member of the harrier genus Circus, and was once considered a subspecies of the eastern marsh harrier (Circus spilonotus) of eastern Asia.
Adult males of the species are distinguished by their silvery-grey plumage, contrasted with a black head, throat, back, and distinctive wing-markings. Their underparts are a striking white. Females, on the other hand, wear a brown coat with a pale rump, a barred tail, and streaked underparts. Juveniles present a blackish-brown coloration with cream-coloured markings on the head, which are more pronounced in females. The size of these birds ranges from 47 to 54 cm, with females typically out-sizing the males.
The Papuan harrier is at home in grasslands and wetlands, and it is known to thrive at elevations up to 3800 meters above sea level.
This species is thinly scattered throughout New Guinea, with the exception of the Vogelkop peninsula in the west. While there have been unconfirmed sightings in Australia, it is often mistaken for the swamp harrier.
With a penchant for hunting low over open ground, the Papuan harrier is an adept hunter, preying on small mammals, birds, and lizards with precision.
This section is not available as the source does not provide information on the song and calls of the Papuan harrier.
This section is not available as the source does not provide information on the breeding habits of the Papuan harrier.
The Papuan harrier can be easily confused with the swamp harrier, especially in regions where their ranges may overlap or in areas of unconfirmed sightings.
The diet of the Papuan harrier consists of small mammals, birds, and lizards, which it hunts with a low, stealthy flight over open terrain.
The IUCN Red List has classified the Papuan harrier as Least Concern, indicating that, at present, the species does not face an immediate threat of extinction.