CR
Nias Hill Myna Gracula robusta



Taxonomy

Taxonomic note
Gracula religiosa, G. venerata, G. robusta and G. indica (del Hoyo and Collar 2016) were previously lumped as G. religiosa following AOU (1998 and supplements) and Sibley and Monroe (1990, 1993).

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
A2bd+3d+4bd; C2a(i) A2bd+3d+4bd; C2a(i); D A2bd+3d+4bd; C2a(i); D1

Red List history
Year Category Criteria
2016 Critically Endangered A2bd+3d+4bd; C2a(i)
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Average mass 192 g
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 12,100 medium
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 50-249 medium estimated 2016
Population trend Decreasing estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 80-100 - - -
Decline (10 years/3 generation past and future) 80-100 - - -
Number of subpopulations 2-100 - - -
Largest subpopulations 1-89 - - -
Generation length (yrs) 4.1 - - -

Population justification: There are potentially two populations, though there are only two recent records of wild individuals on one island and the situation there may be complicated by possible releases that may have taken place. Any wild population on this island numbers fewer than 50 mature individuals. The species has recently been found to still occur at one other island. This population is also clearly small and is here placed in the band 1-49 mature individuals. Concern over poaching from this island is very high. However on another island within the former range the species is apparently now extinct, having disappeared following a period of intense trapping on the island, which principally targeted White-rumped Shama (Eaton et al. 2016).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Indonesia N Extant 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
Forest Subtropical/Tropical Mangrove Vegetation Above High Tide Level suitable resident
Forest Subtropical/Tropical Moist Lowland major resident
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Whole (>90%) Very Rapid Declines High Impact: 9
Stresses
Species disturbance, Hybridisation, Species mortality
Invasive and other problematic species, genes & diseases Timing Scope Severity Impact
Future Whole (>90%) Very Rapid Declines Medium Impact: 7
Stresses
Hybridisation

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2017) Species factsheet: Gracula robusta. Downloaded from http://www.birdlife.org on 22/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/10/2017.