Current view: Data table and detailed info
Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
IUCN Red List criteria met and history
Red List criteria met
Red List history
| Migratory status |
nomadic |
Forest dependency |
high |
| Land-mass type |
|
Average mass |
- |
Population justification: On Guadalcanal, an expedition in 1953 failed to find it (Cain and Galbraith 1956) and there are few recent records (G. Dutson pers. obs. 1997-8, K. D. Bishop in litt. 1999). Hunters at Komarindi reported shooting just one of this species for every 20 D. rubricera (van Oosten and Wyant 1999). On the little-studied island of Malaita, it is known from just one specimen and was seen twice in 1990 (Mayr 1931, Lees 1991, P. Scofield in litt. 1999). On Ugi and Ulawa, it was recorded as abundant in 1953 (Cain and Galbraith 1956). There have been no recent records on Ulawa or the Three Sisters, and it may be extinct on these small islands (G. Dutson pers. obs. 1997-8). A flock of eight individuals was recorded on Ugi in 2015 (Gregory 2015).
On Makira, it was recorded as common from coastal to ridge forest in 1953 (Cain and Galbraith 1956). More recent records include single birds and congregations of up to 20 birds around Hauta (Lees 1991, Buckingham et al. 1995, Gibbs 1996, G. Dutson pers. obs. 1997-8, R. James in litt. 1999). Surveys in 2006 found that the species was fairly common between elevations of 800-900 m (Danielsen et al. 2010). A total of 65 individuals were recorded during surveys in lowland forest in Kahua in 2012 (Davies et al. 2015). During surveys in 2015-2016, the species was observed frequently in flocks of 15-25 individuals in the lowland and hill forests in the south of the island (Mittermeier et al. 2018). The population on Makira appears to have rebounded following controls on guns, and many more individuals were observed in the lowlands in 2016 than had been in previous years (G. Dutson in litt. 2016, Mittermeier et al. 2018). The population on the island is suspected to be greater than 1,000 mature individuals (G. Dutson in litt. 2016).
No direct estimates of population size or population density are available. According to remote sensing data, there were approximately 10,072 km2 of tree cover with at least 30% canopy cover in the species's extant and possibly extinct range in 2010 (Global Forest Watch 2021). Based on the minimum and first quartile recorded densities of congeners (1.1 and 14 individuals/km2, respectively), the area of tree cover stated above, and assuming that tree cover to be 25-40% occupied, the population size may be estimated to fall in the range 2,700 - 59,000 individuals, roughly equating to 1,800 - 39,000 mature individuals. However, there have been few recent records from Guadalcanal, Malaita or Ugi, so the species may be rare on these islands, and no recent records from Ulawa and the Three Sisters, where the species may be extinct. Assuming a minimum of 50 mature individuals on each of Guadalcanal and Malaita, 10 on Ugi, and none on Ulawa or the Three Sisters, the minimum population size is placed at 610 mature individuals. Given the paucity of recent records from Guadalcanal and Malaita, the true population size is likely to fall towards the lower end of this estimate, but the population on Makira is suspected to be greater than 1,000 mature individuals (G. Dutson in litt. 2016), so a best estimate is here placed within the range 1,100 - 19,999 mature individuals.
It is assumed that the populations on Guadalcanal, Malaita and Makira are distinct subpopulations. Assuming that the subpopulation on Makira is the largest, based on the paucity of recent records from other islands, the minimum size of the largest subpoulation is placed at 500 mature individuals based on the area of tree cover and the method above, but it is suspected to be more than 1,000 mature individuals (G. Dutson in litt. 2016). Using the above method and the largest area of tree cover on one island (3,710 km2 on Guadalcanal), the maximum size of the largest subpopulation is placed at 15,000 mature individuals.
Trend justification: From 2001 to 2019, an estimated 7% of tree cover with at least 30% canopy cover was lost from across the species's range (Global Forest Watch 2021). The rate of forest loss was significantly higher over the period 2014-2019, with approximately 4% lost over this period alone. The population size is thus inferred to be undergoing a continuing decline. Based on the above rate of tree cover loss, 7% of tree cover is estimated to have been lost from the species's range over the past 20 years (three generations), and 8-14% is projected to be lost over three generations into the future.
This species appears to be tolerant of moderately degraded forest, although this may be an artefact of increased detectability (G. Dutson in litt. 2016). However, it avoids cacao plantations (Mittermeier et al. 2018), and is reliant on fruiting trees, so forest loss is likely to affect its population size. There may also be an additional population impact of forest degradation caused by logging (G. Dutson in litt. 2021). The population on Makira appears to have rebounded since 2003 following controls on guns, and many more individuals were observed in the lowlands in 2016 than had been in previous years (G. Dutson in litt. 2016, Mittermeier et al. 2018). This pattern may have been replicated in Guadalcanal and Malaita.
The population size is therefore suspected to have undergone an increase over the past three generations, but there is inferred to be a slow continuing decline owing to ongoing forest loss, and a reduction of less than 20% is suspected to take place over the next three generations.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Chestnut-bellied Imperial-pigeon Ducula brenchleyi. Downloaded from
https://datazone.birdlife.org/species/factsheet/chestnut-bellied-imperial-pigeon-ducula-brenchleyi on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/11/2024.
