VU
Biak Lorikeet Trichoglossus rosenbergii



Taxonomy

Taxonomic note

Trichoglossus haematodus, T. forsteni, T. capistratus, T. weberi, T. rubritorquis, T. moluccanus and T. rosenbergii (del Hoyo and Collar 2014) were previously lumped as T. haematodus following Christidis and Boles (1994), and before then were split as T. haematodus and T. rubritorquis following Sibley and Monroe (1990, 1993).

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
- - C2a(ii)

Red List history
Year Category Criteria
2022 Vulnerable C2a(ii)
2016 Vulnerable C2a(ii)
2014 Vulnerable C2a(ii)
Species attributes

Migratory status not a migrant Forest dependency low
Land-mass type Average mass 130 g
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 3,500 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 2500-9999 mature individuals poor estimated 2012
Population trend decreasing - inferred -
Generation length 4.7 years - - -
Number of subpopulations 1 - - -
Percentage of mature individuals in largest subpopulation 100% - - -

Population justification: A preliminary population estimate based on expert knowledge is of 3,000-4,000 individuals, based on rates of encounter within the range of the species (M. Halaouate in litt. 2012). Hence the population size was estimated to fall in the wider band of 2,500-9,999 mature individuals. With reports of a recent notable reduction in abundance a re-estimation of the density and population size is required, but in the absence of a new estimate the existing value is retained.

Trend justification: Recent reports suggest that the species is undergoing a rapid and concerning population reduction. Visiting birdwatchers have noted that the species was very difficult to locate in 2019, while it was common five years previously (Bergmark 2019). Encounters remain regular however, with most visits to the island seeking endemic birds still locating the species (Bergmark 2019, Bocos 2019).


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Indonesia extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Plantations suitable resident
Artificial/Terrestrial Urban Areas suitable resident
Forest Subtropical/Tropical Mangrove Vegetation Above High Tide Level suitable resident
Forest Subtropical/Tropical Moist Lowland suitable resident
Forest Subtropical/Tropical Moist Montane suitable resident
Forest Subtropical/Tropical Swamp suitable resident
Shrubland Subtropical/Tropical Dry suitable resident
Shrubland Subtropical/Tropical Moist suitable resident
Wetlands (inland) Bogs, Marshes, Swamps, Fens, Peatlands suitable resident
Altitude 0 - 700 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Ecosystem degradation, Ecosystem conversion

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Pets/display animals, horticulture - - international non-trivial recent

Recommended citation
BirdLife International (2024) Species factsheet: Trichoglossus rosenbergii. Downloaded from https://datazone.birdlife.org/species/factsheet/biak-lorikeet-trichoglossus-rosenbergii on 22/02/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 22/02/2024.