6 thoughts on “Papuan Harrier (Circus spilothorax)”
I don’t know of any other quantitative data, and I’m aware that this suggestion is subjective speculation, but given the frequency with which this species is seen at all altitudes (eBird and pers. obs.), it seems unlikely that there are <2500 mature individuals.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 2 February 2026. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List category on this page on 2 February 2026, when discussions will re-open.
We thank G. Dutson for their helpful comment above. On this basis, the upper bound of the population size estimate has been expanded to 5,000 mature individuals, while the lower bound of 1,500 mature individuals is retained on a precautionary basis, in the absence of further data.
Based on available information therefore, our preliminary proposal for the 2026 Red List would be to adopt the proposed classification outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 8 February 2026, after which the recommended categorisations will be put forward to IUCN.
The final 2026 Red List categories will be published on the BirdLife and IUCN websites later this year, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Guy, your comment that it is seen frequently at all altitudes is interesting. Could you help quantify that with numbers of birds per km traveled or numbers per square km per habitat. The season is important too of course as they’re almost certainly migratory.
By collecting data from all parts of the island you can assist honing the current population size.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret the information, and a final decision on this species’ Red List category will be posted on this page on 16 February 2026.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Papuan Harrier is recommended to be listed as Near Threatened, approaching thresholds under Criterion C2a(ii).
Many thanks to everyone who contributed to the 2026.1 GTB Forum process. The final Red List categories will be published on the BirdLife and IUCN websites later this year, following further checking of information relevant to the assessments by both BirdLife and IUCN.
I don’t know of any other quantitative data, and I’m aware that this suggestion is subjective speculation, but given the frequency with which this species is seen at all altitudes (eBird and pers. obs.), it seems unlikely that there are <2500 mature individuals.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 2 February 2026. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List category on this page on 2 February 2026, when discussions will re-open.
Preliminary proposal
We thank G. Dutson for their helpful comment above. On this basis, the upper bound of the population size estimate has been expanded to 5,000 mature individuals, while the lower bound of 1,500 mature individuals is retained on a precautionary basis, in the absence of further data.
Based on available information therefore, our preliminary proposal for the 2026 Red List would be to adopt the proposed classification outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 8 February 2026, after which the recommended categorisations will be put forward to IUCN.
The final 2026 Red List categories will be published on the BirdLife and IUCN websites later this year, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Guy, your comment that it is seen frequently at all altitudes is interesting. Could you help quantify that with numbers of birds per km traveled or numbers per square km per habitat. The season is important too of course as they’re almost certainly migratory.
By collecting data from all parts of the island you can assist honing the current population size.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret the information, and a final decision on this species’ Red List category will be posted on this page on 16 February 2026.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Papuan Harrier is recommended to be listed as Near Threatened, approaching thresholds under Criterion C2a(ii).
Many thanks to everyone who contributed to the 2026.1 GTB Forum process. The final Red List categories will be published on the BirdLife and IUCN websites later this year, following further checking of information relevant to the assessments by both BirdLife and IUCN.