Tagula Butcherbird Cracticus louisiadensis


Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and 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
2020 Near Threatened B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(ii)
2016 Data Deficient
2012 Data Deficient
2008 Data Deficient
2004 Data Deficient
2000 Data Deficient
1996 Data Deficient
1994 Data Deficient
1988 Near Threatened
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Average mass -

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 2,000 medium
Extent of Occurrence breeding/resident (km2) 500
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 11500 - 23200 good estimated 2016
Population trend Decreasing good 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) 1-15 - - -
Decline (10 years/3 generation past and future) 1-15 - - -
Number of subpopulations 2-4 - - -
Percentage in largest subpopulation 86-93 - - -
Generation length (yrs) 5 - - -

Population justification: The species is relatively common in suitable habitats across all four islands (Goulding et al. 2019a). Pre-dawn singing males surveyed during the breeding season in 2012-16 occurred at densities of about 0.53 mature individuals/ha on Sabara Island (Goulding et al. 2019a). The species is more patchily distributed on Panawina (0.15/ha), Junet (0.23/ha) and Tagula (0.14-0.30/ha) where it appears to be at lower densities in suitable habitat and absent from some areas of suitable habitat. Conservative extrapolation using forest cover greater than 80% (79,200 ha; Hansen et al. 2013), combined with the observed densities, suggests that the global population of mature individuals is 11,500 - 23,200, although it was noted that this may be a slight overestimate (Goulding et al. 2019a).

The island with the largest population is Tagula, which was estimated to have a population of 10,000–21,500 mature individuals (Goulding et al2019a). The species has been observed crossing water barriers of at least 500m, so it is suspected to have a high dispersal ability (Goulding et al2019a). However, vocal differences between individuals from Sabara and other islands suggest distinct subpopulations.

Trend justification: Over three generations from 2004-2019, approximately 2.8% of tree cover with 75% canopy cover was lost from within the species's range (Global Forest Watch 2020). Although this loss was small, the species prefers intact forest and is therefore inferred to be undergoing a slow continuing decline. Based on this information, the species is suspected to have undergone a population reduction of 1-5% over the past three generations (15 years). In 2019, there were plans for a large logging operation on Tagula, which could affect up to 10% of the species's range. The population is therefore suspected to undergo a reduction of 1-15% 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 Sudest

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Rural Gardens suitable resident
Forest Subtropical/Tropical Moist Lowland major resident
Altitude 0 - 500 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Shifting agriculture Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation
Climate change & severe weather Storms & flooding Timing Scope Severity Impact
Past, Likely to Return Whole (>90%) Causing/Could cause fluctuations Past Impact
Ecosystem degradation, Species mortality
Invasive and other problematic species, genes & diseases Problematic species/disease of unknown origin - Unspecified species Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Reduced reproductive success, Species mortality
Transportation & service corridors Roads & railroads Timing Scope Severity Impact
Future Minority (<50%) Slow, Significant Declines Low Impact: 3
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2021) Species factsheet: Cracticus louisiadensis. Downloaded from http://www.birdlife.org on 02/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 02/12/2021.