LC
Violaceous Coucal Centropus violaceus



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 -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 127,000 medium
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 6700-61000 poor suspected 2021
Population trend Decreasing poor inferred -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 1-18 - - -
Decline (10 years/3 generation past and future) 1-18 - - -
Number of subpopulations 2 - - -
Percentage in largest subpopulation 1-89 - - -
Generation length (yrs) 5.99 - - -

Population justification: It is widely distributed on both range islands, but occurs at low densities (Erritz√łe et al. 2012), and is more common on New Britain than on New Ireland. The population density is thought to be below 0.1 pairs per km2 (Mayr and Diamond 2001).

The population size has been previously estimated to be greater than 10,000 individuals (Buchanan et al. 2008, Davis et al. 2018), which roughly equates to 6,700 mature individuals. Based on a minimum density of 0.3 individuals per km2 (based on the pair density estimate from Mayr and Diamond 2001), a maximum density derived from the first quartile population density estimate from congeners (2.65 individuals per km2), the projected area of tree cover within the range in 2021 (c. 34,300 km2; Global Forest Watch 2021), and assuming the tree cover to be 75-100% occupied, the population size may be tentatively suspected to fall within the range 7,000 - 91,000 individuals, roughly equating to 5,000 - 61,000 mature individuals. Taking into account the previously estimated minimum population size (Buchanan et al. 2008, Davis et al. 2018), the population size is here placed in the band 6,700 - 61,000 mature individuals.

Approximately 80% of the available habitat is on New Britain. Assuming each island holds a single subpopulation, the largest subpopulation may hold approximately 4,000 - 50,000 mature individuals.

Trend justification: The species is inferred to be declining owing to ongoing clearance of lowland forest (Buchanan et al. 2008, Global Forest Watch 2021). Buchanan et al. (2008) calculated the rate of forest loss within the species's range on New Britain as 12.4% over 1990-2000.

Over 18 years (three generations) from 2002-2020, approximately 9% of tree cover with at least 50% canopy cover was lost from within the species's range (Global Forest Watch 2021). Based on this data, it is suspected that 10-13% will be lost over the next three generations.

This species is dependent on forest, but it appears to be more tolerant of forest degradation than previously thought (Davis et al. 2018). The species's population size is therefore suspected to have undergone a reduction of 1-14% over the past three generations, and is suspected to undergo a reduction of 1-18% over the next three generations.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Papua New Guinea N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Papua New Guinea Nakanai Central Pomio

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland suitable resident
Altitude 0 - 760 m Occasional altitudinal limits (max) 1370 m

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 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

Recommended citation
BirdLife International (2022) Species factsheet: Centropus violaceus. Downloaded from http://www.birdlife.org on 22/05/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/05/2022.