CR
Grey-backed Myna Acridotheres tricolor



Justification

Justification of Red List Category
Acridotheres tricolor has been reduced to very low numbers as a result of exploitation for the bird trade (Collar et al. 2012, Eaton et al. 2015, Shepherd et al. 2015). The paucity of records in the field and the increasing rarity of individuals in the cage-bird trade suggest that is suffering an ongoing population decline, to the point where the population is now believed to number fewer than 250 mature individuals. As such, this species qualifies as Critically Endangered, and urgent conservation action is required to halt its unsustainable exploitation for trade.

Population justification
The population is estimated to number fewer than 250 mature individuals in the wild, based on an assessment of recent records pertaining to this species (eBird 2016, S, Mahood in litt. 2009, Eaton et al. 2015). The maximum recent count of individuals is 37 observed together in Baluran (Robson 2016), and 25 in Alas Purwo (Eaton et al. 2015). Addition birds may be present in Meru Betiri, but no recent records have been reported (Eaton et al. 2015). Thorough survey of the remaining populations may reveal that the population is larger than estimated from the limited data available, though the population is clearly very small.

Trend justification
A very rapid decline occurred in the species in the late 20th century attributed to trapping for the cage bird trade (BirdLife International 2001) and in the past five years the species has only been reported at two sites (Eaton et al. 2015). Grey-backed Myna is not as sought after as Black-winged, but still commands a high price (S. Chng in litt. 2016) but in recent years very few have been observed during market surveys (Shepherd et al. 2015, Chng et al. 2015). From this it is inferred that numbers outside of the protected areas must be vanishingly small. Populations within the protected areas are unlikely to be safe from trapping (BirdLife International 2001, Eaton et al. 2015), though the rate of decline inferred from reported records within the last 13 years (3 generations) appears slow. But given that demand for the species in the cage-bird trade is not likely to decrease, this rate of decline is projected to continue into the future.

Distribution and population

The species is endemic to Java, Indonesia. It has undergone a widespread rapid decline since at least the 1960s, when it was common in the plains of East Java, to the east of Gunung Bromo. Now rare and very localised, recent records have come only from Alas Purwo and Baluran National Parks and a few may survive in Meru Betiri National Park (Eaton et al. 2015). 

Ecology

Small flocks forage on the ground in a variety of habitats, particularly agricultural and livestock-grazed areas, chiefly in the extreme lowlands, although occasionally up to c. 2,400 m in East Java. Some recent records have been in association with Banteng. It also inhabits primary and secondary monsoon forest, including teak forest (where it was locally abundant), forest edge and open woodland, uncultivated bushy valleys, and even (formerly at least) urban suburbs.

Threats

Capture for trade is the primary threat, and the main cause of its decline. This species is one of the most popular cage-birds on Java, an island famed for its huge bird markets and very high cage-bird ownership. Surveys conducted in July 2014 in three shops in Jakarta found the average unbartered price for the A. melanopterus group of species per bird was US$ 220, the high price indicating the species' scarcity in the wild (Shepherd et al. 2015). Three A. tricolor were observed for sale in a survey of the bird market in Bandung in September 2016, taken to be an indication of ongoing capture from the wild. Many A. melanopterus are now being captive bred to supply demand since the almost total collapse of the population of that species (Collar et al. 2012, Eaton et al. 2015), but A. tricolor does not appear to be as desirable. Genetic integrity has been lost due to the widespread mixing of the the three subspecies when birds escape (Muchtar and Nurwatha 2001, Collar et al. 2012), but the observation of an A. tricolor A. melanopterus hybrid during the 2016 Bandung survey (S. Chng in litt. 2016) raises concerns that this may be a deliberate strategy by some private breeders, given that higher prices appear to be paid for birds with white mantles (Shepherd et al. 2015). In June 2014, three captive bred individuals were among nearly 160 threatened birds stolen from the Cikananga Conservation Breeding Centre near Sukabumi (Kullmann 2014, Tritto and Sozer 2014). and it appears that there is a greater desire for the A. melanopterus phenotype in the market. It has been suggested that excessive use of pesticides may present a significant threat, as the species habitually forages in open agricultural areas. 

Conservation actions

Conservation and Research Actions Underway
The species has been nominally protected under Indonesian law since 1979. It occurs in at least two protected areas, Baluran National Park and Alas Purwo National Park, Java (Eaton et al. 2015).  

Conservation and Research Actions Proposed
Conduct intensive research into the year-round ecology of the species to clarify its requirements, and the role of trapping and pesticides in causing declines. Promote widespread, strict and effective enforcement of capture and trade regulations (including CITES listing [Shepherd et al. 2015]), focusing activities on protected areas and bird markets. Implement awareness raising activities to discourage people from purchasing protected wildlife (Shepherd et al. 2015). Control use of agricultural pesticides (if these are found to be a significant constraint), especially in key areas for the species. Develop the programme of captive breeding currently focused on A. melanopterus to include the present species (Collar and Butchart 2013) and increase security measures at breeding centres to prevent further incidences of theft (Shepherd et al. 2015).

Identification

23 cm. Medium-sized, stocky, piebald starling. Entirely clean white apart from grey mantle, black wings and tail. Also white rump, tail tip, median coverts and primary bases. Adults have a short white crest, naked yellowish or pinkish skin around eye and yellow bill and legs. Voice Loud, harsh whistles.


Acknowledgements

Text account compilers
Benstead, P., Calvert, R., Derhé, M., Gilroy, J., Khwaja, N., Symes, A., Wright, L & Ashpole, J

Contributors
Brickle, N., Eaton, J., Iqbal, M., Mahood, S., Winnasis, S. & van Balen, B.


Recommended citation
BirdLife International (2017) Species factsheet: Acridotheres tricolor. 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.