Data Zone
Justification of Red List category
Population justification
This species forms multiple subpopulations, based on the three distinct subspecies and their distribution throughout its range. Subspecies melanopterus is possibly extirpated in the wild (eBird 2021, Eaton et al. 2021) with recent records attributed to individuals that have either escaped, or are part of ongoing release attempts to re-establish a population (P.G. Akbar in litt. 2021, S. Brusland in litt. 2021). Subspecies tricolor comprises the largest population, with c.180 birds in Baluran National Park (Squires et al. in press., T. Squires in litt. 2021); at Alas Purwo National Park, the population is now estimated to comprise <5 individuals, with no confirmed sightings since two were seen in June 2019 (P.G. Akbar in litt. 2021). Subspecies tertius had previously been estimated at 200 individuals, with 190 estimated to be present within Bali Barat National Park in 2014 (Eaton et al. 2015). More recent estimates suggest 35-100 birds remain (Brillianti et al. 2019, S. Brusland in litt. 2021, J. Eaton in litt. 2021) in the National Park and surrounding areas. Small numbers of this taxon may also persist on Nusa Lembongan. The global population is therefore estimated at 220-285 birds, equivalent to c.150-190 mature individuals. The largest subpopulation, in Baluran National Park, comprises c.180 birds, equivalent to c.120 mature individuals.
Trend justification
From surveys of three of Indonesia's largest open bird markets conducted between 2010-2014, Shepherd et al. (2015) report that on average, 7 Black-winged myna birds were observed per market survey. This is a reduction of roughly 75% compared to market surveys conducted in 1991-1993, when the average was 30 per market survey. This implies that the population has reduced by roughly 75% in c.20 years. Over a 10 year period, this would be equivalent to a rate of decline of 50%.
Subspecies A. melanopterus is thought to have declined by 80-100% over the 13 years up to 2009 (J. Eaton in litt. 2009) and is now believed to be extirpated in the wild (Eaton et al. 2021) given the demands of the bird trade, as well as the paucity of records in the field. In recent years, very few individuals of A. tricolor have been observed during market surveys. As they still command a high price (S. Chng in litt. 2016), it is likely that this scarcity is due to population declines, rather than a reduction in demand. However, A. tricolor is not as sought after as A. melanopterus (S. Chng in litt. 2016, Nijman et al. 2018), and so the overall rate of decline may not be as high as that for A. melanopterus. While A. tertius remains highly desirable, 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 (Shepherd et al. 2015; S. Chng in litt. 2016). It is therefore not thought that the global population is declining at the same rates reported for A. melanopterus.
The rate of decline is still thought to be high, and is suspected to fall into the band of 10-49% over 10 years. It is unlikely that the demands of the bird trade will cease soon, so the rates of decline are suspected to continue into the future.
The species is endemic to the islands of Java and Bali, Indonesia, also occurring on adjacent Madura and Nusa Penida, and (perhaps only as a vagrant or escapee) on Lombok. There are three subspecies, nominate melanopterus in most of Java, tricolor in south-east Java and tertius on Bali (Collar et al. 2012).
It was formerly common in the plains of East Java, and locally common in central and west Java, but is now rare and very localised throughout. A similar decline has also occurred on Bali and Nusa Penida, and there are very few records from Madura or Lombok. A survey of 33 historical locations revealed just 32 individuals at only three locations (Muchtar and Nurwatha 2001). Despite regular checks of several bird markets in Java this species is rarely recorded, and according to sellers they are now very difficult to find (J. Eaton in litt. 2009), and only small numbers were sighted in 2009 at Pulau Dua, Baluran National Park, Alas Purwo National Park (all on Java), and at the Menjangan Jungle Beach Resort and Uluwatu on Bali (J. Eaton, M. Iqbal, S. Mahood and S. Winnasis in litt. 2009).
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. 1,300 m in West Java and 2,400 m in East Java. 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. Some flocks on Bali were thought to make significant local movements, following the flowering and fruiting of trees.
Capture for trade is the primary threat, and the main cause of its decline. The species remains highly desirable and is one of the most popular cage-birds on Java, an island famed for its huge bird markets and very high cage-bird ownership. Prices appear to have peaked in 2014 when the mean (inflation correct) price was around US$ 140, but in 2018 prices were down to around US$ 85 (similar to that in 2012-2013; Nijman et al. 2018). There continues to be little enforcement and checking of which birds are wild-caught or captive-bred, with 10,000-15,000 being sold annually (Nijman et al. 2018). Although captive-breeding is assumed to be producing all the birds being sold, birds without closed rings were still being observed in markets 2014-2018 (Shepherd et al. 2015, Nijman et al. 2018) and current legislation and market operations do not appear to provide any disincentive to the capture of wild birds, which continue to be poached, even in protected areas, with the taking of three juveniles from Bali Barat National Park in May 2021 (J. Eaton in litt. 2021) and the trade of 19-24 individuals April 2020-March 2021, at least some of which were traced to Baluran National Park (Brusland et al. 2021). The species's desirability is clearly illustrated by the organised theft in June 2014 of 149 captive bred A. melanopterus from the Cikananga Conservation Breeding Centre near Sukabumi (Kullmann 2014, Tritto and Sözer 2014), and commercial breeders are also now targeted.
Additionally, genetic integrity has been lost due to the widespread mixing of the the three subspecies when birds escape, and seemingly sometimes deliberately in captive breeding for the market (Collar et al. 2012, S. Chng in litt. 2016); for example, 90% of traded birds (across all three subspecies monitored) during 2018 surveys were the nominate subspecies melanopterus, suggesting the continued intensity in its trade (Nijman et al. 2018). Private ownership of the species is also thought to number c. 40,000 birds in Indonesia alone, with breeding for commercial purposes heaviest in Klaten (Central Java), but does not exclude larger cities across Java and Bali (Nijman et al. 2018).
It has been suggested that excessive use of pesticides may have previously presented a significant threat, as the species habitually forages in open agricultural areas. The West Java region has additionally lost 40% of its 8,650 km2 montane forests in the period of 1990-2015 (Higginbottom et al. 2019); this may have further compounded the extensive trapping of the species and may have lead to higher susceptibility of the native population to imminent extinction.
Conservation and Research Actions Underway
Black-winged mynas were added to Indonesia's protected species list in 1979 (Decree by the Ministry of Agriculture, SK Mentan 757/Kpts/Um/12/1979). This was later consolidated into a Government Regulation Number 7 on Protected Animals and Plants (PP 7/1999). This legislation makes it illegal to catch, transport, and trade Black-winged Mynas or transfer them from one place to another, within or outside Indonesia. Penalties that can be imposed when these laws are broken can total fines of up to IDR 100,000,000 (c.US$ 7,250) and imprisonment for up to five years.
It occurs in at least three protected areas, Baluran National Park and Pulau Dua Reserve, Java (B. van Balen in litt. 2007), and with a maximum population of 35-100 birds at Bali Barat National Park, Bali (S. Brusland in litt. 2021, J. Eaton in litt. 2021). Conservation projects have been carried out on Java (Owen et al. 2014): a breeding programme at the Cikananga Wild Animal Rescue Centre in Sukabumi, West Java, and planned future reintroduction of birds in Cikepuh Nature Reserve (Braasch 2007). The Cikananga breeding programme (holding birds of the nominate form) had produced over 200 chicks by early 2012, and 25 birds were released into nearby regenerating forest as a trial reintroduction in 2012, using nestboxes made in local villages (Collar et al. 2012). In the Rawadanau Nature Reserve in Banten Province,on 25th December 2013, 25 birds were released with 21 remaining at the end of December (Tritto 2014). At the Bogor Taman Safari facilities, a trial release has seen a growing population since 2016 peaking at c.55 free-flying birds in 2020, but dropped to less than 25 birds in 2021 due to a localised storm. The birds are breeding in the wild in natural and artificial nesting cavities and are to a degree subject to supplemental feeding. There is an ongoing monitoring and community engagement preventing trapping on grounds and in most surrounding areas. Trapping interest have however been recorded at the fringe of the area (S. Brusland in litt. 2021).
Facilities that breed Black-winged Mynas are obliged to reintroduce 10% of their birds back into the wild. This obligation is not enforced and does not appear to be followed rigidly. Concern has been raised that these obligations mean that, in theory, hundreds of birds should be being released in different parts of Java, Bali, Lombok and Madura, without proper habitat assessments, health checks, genetic screening, post-release monitoring, or consideration for which of the three species are being released where (Nijman et al. 2018). In addition, authorities are known to release confiscated birds back into the wild, but in at least two cases, A. m. melanopterus were released within the native range of A. m. tricolor and A. m. tertius (Nijman et al. 2018).
23 cm. Medium-sized, stocky, piebald starling. Entirely clean white apart from black wings and tail. Also white rump, tail tip, median coverts and primary bases. Mantle colour varies racially between slate-grey and white. Adults have a short white crest, naked yellowish or pinkish skin around eye and yellow bill and legs. Similar spp. Bali Starling Leucopsar rothschildi has black restricted to tips of wings and tail, much longer white crest, blue eye-ring and blue-grey legs. Voice Loud, harsh whistles.
Text account compilers
Berryman, A., Clark, J.
Contributors
Ashpole, J, Benstead, P., Brickle, N., Calvert, R., Derhé, M., Eaton, J., Gilroy, J., Iqbal, M., Khwaja, N., Mahood, S., Symes, A., Winnasis, S., Wright, L, van Balen, B.S., Akbar, P. & Brusland, S.
Recommended citation
BirdLife International (2024) Species factsheet: Black-winged Myna Acridotheres melanopterus. Downloaded from
https://datazone.birdlife.org/species/factsheet/black-winged-myna-acridotheres-melanopterus on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.