5 thoughts on “Solomons Island-thrush (Turdus kulambangrae)”
(1) I have seen no evidence of habitat loss at these high altitudes other than the natural landslips which regenerate into habitat suitable for this species and are easily detected by satellite imagery, so I suggest that neither taxon is declining due to habitat loss.
(2) The Kolombangara taxon has been recorded down to 1040 m but very uncommon below 1100 m, which is a more meaningful lower altitudinal limit to use here. Similarly, the Guadalcanal taxon is uncommon below 1300 m.
(3) The population size for the Kolombangara taxon is estimated in Buckingham et al as 25 birds / km2 in primary montane forest and and 33 birds / km2 in mossy forest [which is above about 1300 m] in 1990. If we estimate 100 km2 above 1200 m (but BirdLife could easily calculate a more accurate area), the population size for this taxon is about 3000 individuals.
(4) The population size for the Guadalcanal taxon is estimated here based on a total of 43 birds in 31 hours of quantified surveys in primary montane forest between 1250-1660 m in 1997. This taxon is unobtrusive except that it usually vocalises loudly when it sees people, so an effective detection distance of 10 m each side of the path seems reasonable, meaning that these encounter rates are approximately equivalent to 43/31/0.02 = 70 birds / km2. If we estimate 500 km2 above 1200 m (but BirdLife could easily calculate a more accurate area), the population size for this taxon is about 30,000 individuals. Thus taxon clearly exceeds the 10,000 mature individuals under criterion C.
(5) The AOO might be <500 km2 – requires BirdLife to map it
(6) The empirical data for population change for the Kolombangara taxon are very sparse: Buckingham et al give encounter rates of 25 birds / km2 in primary montane forest and and 33 birds / km2 in mossy forest in 1990. This taxon is unobtrusive except that it usually vocalises loudly when it sees people, so an effective detection distance of 10 m each side of the path seems reasonable, meaning that the Buckingham et al encounter rates are approximately equivalent to 0.5-0.7 birds / km. In 1998, I only recorded 3 birds in 16.5 hours or perhaps 10 km. The only records on eBird are 2 in 8h/2.5km in 2019 and 1 in 3h/1km in 2025.)
There are too few data to make any comment about trends of the Guadalcanal taxon.
(7) Pending any better evidence of decline son Kolombangara, I suggest that it is best categorised as LC
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. Based on this, there is no longer considered to be a continuing decline in habitat area, extent or quality for this species, and the assessment will be updated accordingly. The population size is thought to exceed 10,000 mature individuals, and there is no evidence it meets or approaches thresholds under any other criteria.
Based on available information therefore, our preliminary proposal for the 2026 Red List would be to list Solomons Island-thrush as Least Concern. 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. Solomons Island-thrush is recommended to be listed as Least Concern.
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) I have seen no evidence of habitat loss at these high altitudes other than the natural landslips which regenerate into habitat suitable for this species and are easily detected by satellite imagery, so I suggest that neither taxon is declining due to habitat loss.
(2) The Kolombangara taxon has been recorded down to 1040 m but very uncommon below 1100 m, which is a more meaningful lower altitudinal limit to use here. Similarly, the Guadalcanal taxon is uncommon below 1300 m.
(3) The population size for the Kolombangara taxon is estimated in Buckingham et al as 25 birds / km2 in primary montane forest and and 33 birds / km2 in mossy forest [which is above about 1300 m] in 1990. If we estimate 100 km2 above 1200 m (but BirdLife could easily calculate a more accurate area), the population size for this taxon is about 3000 individuals.
(4) The population size for the Guadalcanal taxon is estimated here based on a total of 43 birds in 31 hours of quantified surveys in primary montane forest between 1250-1660 m in 1997. This taxon is unobtrusive except that it usually vocalises loudly when it sees people, so an effective detection distance of 10 m each side of the path seems reasonable, meaning that these encounter rates are approximately equivalent to 43/31/0.02 = 70 birds / km2. If we estimate 500 km2 above 1200 m (but BirdLife could easily calculate a more accurate area), the population size for this taxon is about 30,000 individuals. Thus taxon clearly exceeds the 10,000 mature individuals under criterion C.
(5) The AOO might be <500 km2 – requires BirdLife to map it
(6) The empirical data for population change for the Kolombangara taxon are very sparse: Buckingham et al give encounter rates of 25 birds / km2 in primary montane forest and and 33 birds / km2 in mossy forest in 1990. This taxon is unobtrusive except that it usually vocalises loudly when it sees people, so an effective detection distance of 10 m each side of the path seems reasonable, meaning that the Buckingham et al encounter rates are approximately equivalent to 0.5-0.7 birds / km. In 1998, I only recorded 3 birds in 16.5 hours or perhaps 10 km. The only records on eBird are 2 in 8h/2.5km in 2019 and 1 in 3h/1km in 2025.)
There are too few data to make any comment about trends of the Guadalcanal taxon.
(7) Pending any better evidence of decline son Kolombangara, I suggest that it is best categorised as LC
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. Based on this, there is no longer considered to be a continuing decline in habitat area, extent or quality for this species, and the assessment will be updated accordingly. The population size is thought to exceed 10,000 mature individuals, and there is no evidence it meets or approaches thresholds under any other criteria.
Based on available information therefore, our preliminary proposal for the 2026 Red List would be to list Solomons Island-thrush as Least Concern. 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. Solomons Island-thrush is recommended to be listed as Least Concern.
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.