5 thoughts on “Kolombangara Monarch (Symposiachrus browni)”
(1) Global deforestation analyses don’t consider degradation from commercial logging which is severe in the Solomon Islands and the species will be declining at a faster rate than given here (precautionary, I would guess 20-29% in three generations)
(2) Buckingham et al report densities as 39, 58 and 75 contacts per km2 in old-growth lowland, hill and lower montane forest respectively on Kolombanaga (and zero in secondary forest). Global Forest Watch estimates 470 kha of natural forest in Western Division of which about 60% or 280 kha are within this species’ range. Global Forest Watch does not estimate the % that is degraded (through logging) but I estimate this to be about 80% for these largely lowland islands, suggesting 60kha or 600 km2 of suitable habitat. I estimate about 30% to be lowland, 60% to be hill and 10% to be lower montane, giving an estimated species’ population size of 39*0.3*600, 58*0.6*600 and 75*0.1*600 = 30000 individuals (rounded to the nearest one significant figure given the degree of uncertainty in these estimates).
(3) Consider adding ‘in primary / old-growth forest’ to the references to its occurrence on New Georgia (as cited by Blaber 1990) and Tetepare (which is 100% old growth).
(4) Please remove Buckingham et al from the reference to the species being commoner on New Georgia as this report merely cites Blaber 1990
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, and all relevant information will be incorporated into the updated Red List assessment for this species. Based on this, the suspected rate of decline has been revised to 15-25%, noting that the rate of decline for this forest-dependent species likely exceeds that of remote-sensed tree cover loss and that declines plausibly exceed 20% within three generations. The species therefore also approaches threatened thresholds under Criteria A2c+3c+4c.
Based on available information, our preliminary proposal for the 2026 Red List would be to list Kolombangara Monarch as Near Threatened under Criteria A2c+3c+4c; B1b(ii,iii,v). 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.
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. Kolombangara Monarch is recommended to be listed as Near Threatened, approaching thresholds under Criteria A2c+3c+4c; B1b(ii,iii,v).
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.
(1) Global deforestation analyses don’t consider degradation from commercial logging which is severe in the Solomon Islands and the species will be declining at a faster rate than given here (precautionary, I would guess 20-29% in three generations)
(2) Buckingham et al report densities as 39, 58 and 75 contacts per km2 in old-growth lowland, hill and lower montane forest respectively on Kolombanaga (and zero in secondary forest). Global Forest Watch estimates 470 kha of natural forest in Western Division of which about 60% or 280 kha are within this species’ range. Global Forest Watch does not estimate the % that is degraded (through logging) but I estimate this to be about 80% for these largely lowland islands, suggesting 60kha or 600 km2 of suitable habitat. I estimate about 30% to be lowland, 60% to be hill and 10% to be lower montane, giving an estimated species’ population size of 39*0.3*600, 58*0.6*600 and 75*0.1*600 = 30000 individuals (rounded to the nearest one significant figure given the degree of uncertainty in these estimates).
(3) Consider adding ‘in primary / old-growth forest’ to the references to its occurrence on New Georgia (as cited by Blaber 1990) and Tetepare (which is 100% old growth).
(4) Please remove Buckingham et al from the reference to the species being commoner on New Georgia as this report merely cites Blaber 1990
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, and all relevant information will be incorporated into the updated Red List assessment for this species. Based on this, the suspected rate of decline has been revised to 15-25%, noting that the rate of decline for this forest-dependent species likely exceeds that of remote-sensed tree cover loss and that declines plausibly exceed 20% within three generations. The species therefore also approaches threatened thresholds under Criteria A2c+3c+4c.
Based on available information, our preliminary proposal for the 2026 Red List would be to list Kolombangara Monarch as Near Threatened under Criteria A2c+3c+4c; B1b(ii,iii,v). 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.
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. Kolombangara Monarch is recommended to be listed as Near Threatened, approaching thresholds under Criteria A2c+3c+4c; B1b(ii,iii,v).
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.