LC
Red-knobbed Imperial-pigeon Ducula rubricera



Taxonomy

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
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2021 Least Concern
2016 Near Threatened A2c+3c+4c
2012 Near Threatened A2c+3c+4c
2008 Near Threatened A2c; A3c; A4c
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type Average mass 652 g
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 592,000 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 150000-750000 mature individuals poor suspected 2021
Population trend decreasing poor inferred 2020-2042
Rate of change over the future 10 years/3 generations (longer of the two periods) 1-16% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 1-16% - - -
Generation length 7.49 years - - -
Number of subpopulations 2-20 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: It is common in lowland forest in the Solomon Islands and New Britain (Blaber 1990, Kratter et al. 2001, Danielsen et al. 2010, Read 2013, Robbins and Robles Bello 2016, Davis et al. 2018, Callaghan et al. 2019). In a study by Davis et al. (2018) involving 415 hours of bird surveys on New Britain, this vocal species had the highest encounter rate of any bird (Davis et al. 2018, R. Davis in litt. 2020). No population density estimates are available, but the population size is suspected to be greater than 10,000 mature individuals (Buchanan et al. 2008, Davis et al. 2018).

The species has a large range, with an estimated 68,400 km2 of tree cover with at least 30% canopy cover within its range in 2010 (Global Forest Watch 2021). Although this area of tree cover is likely to include oil palm plantations, the species has been recorded as common in the lowlands in a number of surveys across its range, so the population size is likely to be very large. Based on the first quartile and median recorded densities of congeners (14.5 and 38 individuals/km2, respectively), the area of tree cover stated above, and assuming that tree cover to be 25-40% occupied, the population size is tentatively suspected to fall in the range 150,000 - 750,000 mature individuals.

The species has two subspecies, a fairly high dispersal ability, and occurs on a large number of islands. The number of subpopulations is suspected to fall within the range 2-20, based on a visual assessment of its range.

Trend justification: It is suspected to have declined in recent decades owing to ongoing clearance of lowland forest, at least in parts of its range (Buchanan et al. 2008). From 2001 to 2020, an estimated 9% of tree cover with at least 30% canopy cover was lost from across the species's range (Global Forest Watch 2021). The population size is thus inferred to be undergoing a continuing decline.

Based on the above rate of tree cover loss, 10% of tree cover is estimated to have been lost from the species's range over the past 22 years (three generations), and 11-16% is projected to be lost over three generations into the future. This species is tolerant of degraded forest, so its population size may not be declining at the same rate as deforestation, but it avoids oil palm plantations and more heavily degraded areas (Davies et al. 2015, Davis et al. 2018, G. Dutson in litt. 2021), so forest loss is likely to affect its population size. However, the population in the Solomon Islands appears to have become more easily detectable since the early 2000s following controls on guns (R. James in litt. 2021). Therefore, the population change over the past three generations is not known, but it is suspected to undergo a reduction of 1-16% over the next three generations.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Papua New Guinea extant native yes
Solomon Islands extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Solomon Islands East Makira
Solomon Islands Gizo
Solomon Islands Mount Maetambe - Kolombangara River

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Plantations marginal resident
Artificial/Terrestrial Rural Gardens marginal resident
Artificial/Terrestrial Subtropical/Tropical Heavily Degraded Former Forest major resident
Forest Subtropical/Tropical Moist Lowland suitable resident
Altitude 0 - 1200 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Negligible declines Low Impact: 5
Stresses
Species disturbance, Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Ecosystem degradation, Ecosystem conversion

Utilisation
Purpose Scale
Food - human

Recommended citation
BirdLife International (2024) Species factsheet: Red-knobbed Imperial-pigeon Ducula rubricera. Downloaded from https://datazone.birdlife.org/species/factsheet/red-knobbed-imperial-pigeon-ducula-rubricera on 23/12/2024.
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 23/12/2024.