5 thoughts on “Vella Lavella Monarch (Symposiachrus nigrotectus)”
I believe it is very plausible that this uncommon taxon meets the criteria for VU C1. In an emailed spreadsheet, I have entered all quantified data from eBird and my notebooks which total 17 individuals in 59 km of fieldwork = 0.3 birds/km. Consistent with Buckingham et al (1990), I estimate an effective detection distance of about 10 m either side of the paths for silent individuals and 50 m for vocalising individuals (noting that these are relative vocal and conspicuous birds, often in mixed flocks, and usually sought after by visiting birders). Most eBird lists don’t differentiate between visual and aural records; as most encounters are aural, but an unknown proportion of individuals are vocalising as the observer passes, I have assumed an effective detection distance of 10-30 m. This suggests a population density of 5-7 birds/ km². Vella Lavella is 629 km² and Ranongga is 147 km². I estimate that 30-70% of the land area is suitable for this species, suggesting a total population of 1200-8200 individuals.
Declines of 5-15%/3 generations seems reasonable, noting the risk that there might be extensive logging and a higher rate of decline. I note that declines should be ‘estimated’ but the Red List also calls for a plausible precautionary approach in the absence of robust data, meaning that C1 can be used.
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.
According to IUCN guidelines, to meet the thresholds for Vulnerable under C1 the rate of continuing decline must be estimated – it cannot be inferred or suspected. The rate of decline has not been directly quantified in this case; it is only suspected based on ongoing rates of habitat loss. The species therefore approaches, but does not meet, threatened thresholds under Criterion C1.
However, the density estimate of 5-7 birds/km2 and the total land area of 776 km2, accounting for 30-70% of this area representing suitable habitat, yields a total population estimate of 1,150-3,800 individuals. This would place the subpopulation on Ranongga at approximately 200-750 individuals and the largest on Vella Lavella at 900-3,100. The species therefore meets the thresholds for Vulnerable under C2a(i) as the lower bound estimate of the largest subpopulation falls below 1,000 mature individuals.
Based on available information, our preliminary proposal for the 2026 Red List would be to list Vella Lavella Monarch as Vulnerable under Criterion C2a(i). 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.
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. Vella Lavella Monarch is recommended to be listed as Vulnerable under Criterion C2a(i).
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 believe it is very plausible that this uncommon taxon meets the criteria for VU C1. In an emailed spreadsheet, I have entered all quantified data from eBird and my notebooks which total 17 individuals in 59 km of fieldwork = 0.3 birds/km. Consistent with Buckingham et al (1990), I estimate an effective detection distance of about 10 m either side of the paths for silent individuals and 50 m for vocalising individuals (noting that these are relative vocal and conspicuous birds, often in mixed flocks, and usually sought after by visiting birders). Most eBird lists don’t differentiate between visual and aural records; as most encounters are aural, but an unknown proportion of individuals are vocalising as the observer passes, I have assumed an effective detection distance of 10-30 m. This suggests a population density of 5-7 birds/ km². Vella Lavella is 629 km² and Ranongga is 147 km². I estimate that 30-70% of the land area is suitable for this species, suggesting a total population of 1200-8200 individuals.
Declines of 5-15%/3 generations seems reasonable, noting the risk that there might be extensive logging and a higher rate of decline. I note that declines should be ‘estimated’ but the Red List also calls for a plausible precautionary approach in the absence of robust data, meaning that C1 can be used.
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.
According to IUCN guidelines, to meet the thresholds for Vulnerable under C1 the rate of continuing decline must be estimated – it cannot be inferred or suspected. The rate of decline has not been directly quantified in this case; it is only suspected based on ongoing rates of habitat loss. The species therefore approaches, but does not meet, threatened thresholds under Criterion C1.
However, the density estimate of 5-7 birds/km2 and the total land area of 776 km2, accounting for 30-70% of this area representing suitable habitat, yields a total population estimate of 1,150-3,800 individuals. This would place the subpopulation on Ranongga at approximately 200-750 individuals and the largest on Vella Lavella at 900-3,100. The species therefore meets the thresholds for Vulnerable under C2a(i) as the lower bound estimate of the largest subpopulation falls below 1,000 mature individuals.
Based on available information, our preliminary proposal for the 2026 Red List would be to list Vella Lavella Monarch as Vulnerable under Criterion C2a(i). 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.
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. Vella Lavella Monarch is recommended to be listed as Vulnerable under Criterion C2a(i).
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.