CR
Grey-rumped Myna Acridotheres tertius



Taxonomy

Taxonomic note
Acridotheres melanopterus, A. tricolor and A. tertius (del Hoyo and Collar 2016) were previously lumped as Sturnus melanopterus following Sibley & 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
C2a(ii) C2a(i,ii); D C2a(i,ii); D1

Red List history
Year Category Criteria
2016 Critically Endangered C2a(ii)
Species attributes

Migratory status not a migrant Forest dependency Low
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1,700 medium
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 50-249 poor estimated 2015
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) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 2 - - -
Largest subpopulations 90-94 - - -
Generation length (yrs) 4.44 - - -

Population justification: The population has been estimated at 200 individuals, with 190 estimated to be present within Bali Barat National Park in 2014 (Eaton et al. 2015). A very small number are present in the south of Bali, estimated to be 10 or fewer (Eaton et al. 2015). Assuming that the species is present on Nusa Lembongan there may a small number of additional birds but releases appear to be ongoing (Collar et al. 2012) and as it is not clear that there is an established breeding population, these are not included in the population estimate.

Trend justification: The population is inferred to be declining from the increasing rarity of this species in the cage-bird trade and dramatically increasing price, however records from the wild within its now very restricted range indicate that the rate of decline is not as great as that noted in A. melanopterus. The species remains highly desirable (captive-bred individuals costing over US$ 120 [Shepherd et al. 2015, S. Chng in litt. 2016]) and while there is little enforcement over the origin of birds offered for sale any birds that do remain in the wild are at risk of being captured and sold. Captive-breeding of the species is assumed now to be producing virtually all the birds being sold, but birds without closed rings were still being observed in the markets in 2014 (Shepherd et al. 2015). The current operation of the market does not appear to provide any disincentive to the capture of wild birds (Shepherd et al. 2016). But the restricted nature of the locations, and enforcement efforts ongoing to prevent capture of Bali Starling Leucopsar rothschildi at which this species is found and the slightly lower desirability than the white mantled A. melanopterus appears to limit the extremes to which trappers are prepared to go to to obtain this species.


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 Arable Land suitable resident
Artificial/Terrestrial Pastureland suitable resident
Forest Subtropical/Tropical Dry suitable resident
Savanna Dry suitable resident
Shrubland Subtropical/Tropical Dry suitable resident
Shrubland Subtropical/Tropical Moist suitable resident
Altitude 0 - 2400 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Reduced reproductive success, Species mortality
Pollution Agricultural & forestry effluents Timing Scope Severity Impact
Ongoing Unknown Slow, Significant Declines Unknown
Stresses
Ecosystem degradation, Reduced reproductive success, Species mortality

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: Acridotheres tertius. Downloaded from http://www.birdlife.org on 12/12/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 12/12/2017.