Bali Starling & Black-winged Starling (BirdingASIA, Dec. 2012)

Various notable and expert writers contributed to 'Conservation breeding and the most threatened birds in Asia' (BirdingASIA, Nr. 18, December 2012) amongst which the Bali Starling & the Black-winged Starling. Below article covers pages 50-53.

BirdingASIA-2012-12-coverConservation breeding and the most threatened birds in Asia: Introduction

Image right: BirdingASIA, December 2012, cover

The role of public and private zoos, aviaries and bird gardens in the conservation of threatened birds has not, for the most part, been pivotal - or at least not so far. A recent review of the value of zoos to bird conservation (Collar 2012 and in prep.) suggested that projects involving captive breeding {ex situ) projects - referred to by zoos as 'conservation breeding' to distinguish this from captive breeding of wildlife for commercial, recreational or other purposes - can be broken down into six general types (to some extent overlapping): 1. 'necessary' - the only conservation option available since the species is extinct in the wild 2. 'integral' - one of several key tools 3. 'precautionary' - providing a back-up population 4. 'prudent' - making best use of existing captive populations 5. 'motivational' - building support for conservation 6. 'market-driven' - meeting trade demand.

'Necessary' ex situ projects have involved the Hawaiian Goose Branta sandvicensis, California Condor Gymnogyps californianus, Alagoas Curassow Mitu mitu, Guam Rail Gallirallus owstoni, Socorro Dove Zenaida graysoni, Spix's Macaw Cyanopsitta spixii and Bali Starling Leucopsar rothschildi, but also in this top priority class of 'zoo species' is a second group where birds survive in the wild, but in such tiny, uncertain or vulnerable numbers that ex situ programmes are deemed to be vital - Madagascar Pochard Aythya innotata, Baer's Pochard A. baeri, Edwards's Pheasant Lophura edwardsi, Spoon-billed Sandpiper Eurynorhynchus pygmeus, Negros Bleeding-heart Gallicolumba keayi, Blue-crowned Laughingthrush Garrulax courtoisi, Black-and-white Laughingthrush G. bicolor, Black-winged Starling Sturnus melanopterus and Javan Green Magpie (formerly Short-tailed Green Magpie) Cissa thalassina.

Notable in the first group is the presence of only a single Asian species; notable in the second is the presence of only one species that is not Asian. Moreover, although only two Asian birds (Crested Ibis Nipponia nippon and Houbara Bustard Chlamydotis undulata) appear among the 16 species judged appropriate to list under the 'integral' projects, the 23 species on the 'precautionary' list contain 10 Asian birds (White-rumped Vulture Gyps bengalensis, Indian Vulture G. indicus, Long-billed Vulture G. tenuirostris, Red-headed Vulture Sarcogyps calvus, Western Tragopan Tragopan melanocephalus, Bornean Peacock Pheasant Polyplectron schleiermacheri, Siberian Crane Grus leucogeranus, Yellow-crested Cockatoo Cacatua sulphurea, Philippine Cockatoo C. haematuropygia and Visayan Wrinkled Hornbill Aceros waldeni).

Meanwhile the 'prudent' list includes White-winged Duck Cairina scutulata, Oriental Stork Ciconia boyciana, Greater Adjutant Leptotilos dubius, Lesser Adjutant L. javanicus, Cheer Pheasant Catreus wallichii, Brown Eared Pheasant Crossoptilon mantchuricum, Chinese Monal Lophophorus Ihuysii, Sclater's Monal L. sclateri, Bulwer's Pheasant Lophura bulweri, Crestless Fireback L. erythrophthalma, Green Peafowl Pavo muticus, Mountain Peacock Pheasant Polyplectron inopinatum, Malayan Peacock Pheasant P. malacense, Palawan Peacock Pheasant P. napoleonis, Reeves's Pheasant Syrmaticus reevesii, Blyth's Tragopan Tragopan blythii, Cabot's Tragopan T. caboti, Salmon-crested Cockatoo Cacatua moluccensis, White Cockatoo C. alba and Red-and-blue Lory Eos histrio. The 'motivational' list is less specific, but includes the Philippine Eagle Pithecophaga jefferyi, all cranes and all large hornbills, while the 'market-driven' list, relatively small and illustrative only, includes Straw-headed Bulbul Pycnonotus zeylanicus, Green Avadavat Amandava formosa, Java Sparrow Padda oryzivora and Timor Sparrow P. fuscata.

Finally, there are additional species that have been or might be considered for ex situ work. BirdLife's 'Datazone' recommends Gurney's Pitta Pitta gurneyi and Taiwan Bulbul Pycnonotus taivanus for possible captive breeding. In addition there are worrying species which others have thought could be important targets for conservation breeding; these include Okinawa Rail Gallirallus okinawae, Great Indian Bustard Ardeotis nigriceps, Mindoro Bleeding-heart Gallicolumba platenae, Green Racquet-tail Prioniturus luconensis, Blue-winged Racquet-tail P. verticalis, Sulu Hornbill Anthracoceros montani and Mindoro Hornbill Penelopides mindorensis (Collar 2012 and in prep.).

BirdingASIA-2012-12-BWS1Image left: Plate 1. Black-winged Starling Sturnus melanopterus melanopterus, Maura Angke Nature Reserve, Jakarta, Java, Indonesia, 30 January 2010 (Ady Kristanto)

With more than 50 Asian species listed above, the role of zoos in the future of birds in general, and Asian birds in particular, looks rather more central. In recent years, many zoos have shifted their remits and identities so as to engage directly with in situ conservation, but there is usually and understandably a need to link such work to species held in their collections. Equally, however, they have responded to external pressure from conservation interests by reducing their holdings of species with little or no conservation need and using the free space for species requiring significant assistance. Even so, few zoos have the capacity to undertake single-species conservation projects single-handed, and many have joined forces to develop a more coherent and robust response to the particular issues that they wish to tackle. In this paper we report on one such initiative, taken under the umbrella of the European Association of Zoos and Aquaria (EAZA), which addresses the conservation of some of the most threatened passerines in Asia.

The people involved represent an amalgam of those concerned initially with the Bali Starling and the Black-winged Starling, and those concerned initially with the Blue-crowned Laughingthrush. The 'starling people', led by David Jeggo of Jersey (now Durrell) Wildlife Conservation Trust and Theo Pagel of Cologne (Koln) Zoo, met first at BirdLife's headquarters in Cambridge in January 2004 to discuss how aviculture could best help advance the interests of the two threatened starlings endemic to Java and Bali. The 'laughingthrush people', led by Laura Gardner of London Zoo (formerly of Leeds Castle, Kent) and Roger Wilkinson of Chester Zoo, met almost annually at BirdLife's headquarters throughout the 2000s, planning both the captive breeding of the species and the next steps in the field research they were funding. Eventually, at Chester Zoo in June 2011 and at Plzen Zoo, Czech Republic, in May 2012, the two parties merged into an EAZA 'Threatened Songbirds of Asia Working Group' (TSAWG), building and broadening their remit to the extent that the name of the group is still only tentative - its future targets may not all be songbirds.

Bali Starling

The history of the Bali Starling's steady decline to virtual extinction in the wild at its single known site, Bali Barat National Park, is told in depressing detail in BirdLife International (2001). In a country where keeping birds in captivity is a national pastime (Jepson & Ladle 2005), the covert demand for such an electrifyingly beautiful and desperately rare species was something the wildlife authorities could not possibly control. As such the Bali Starling became a status symbol with a very high commercial value. Relentless, systematic poaching cancelled out all endeavours to save and supplement the wild population. When in 1999 the park's headquarters were ram-raided by armed robbers and 39 birds stolen from the pre-release training centre, everyone got a measure of just how ruthless and unstoppable the forces were behind the poaching pressure.

This poaching pressure still continues, although there are moves towards breeding Bali Starlings in captivity both for release and for the private market. Supplementation work, begun in the 1990s with birds contributed from the USA and Europe, has continued, now mostly drawing on stock sent from Japan and from local breeders. There is a government scheme that allows local Balinese to get captive stock on 'breeding loan' and give a relatively small proportion of the resulting offspring to the park whilst being able to sell the remaining progeny commercially. In recent years as many as 126 birds have been set free by the government wildlife agency in Bali Barat, according to verbal reports by park staff, but these have been 'hard releases' (meaning that the birds have to cope immediately with their new surroundings rather than be eased into them by the provision of food and water over a period of weeks), and there is no monitoring of their survival. Long-term international collaboration with the park is rendered problematic by the frequent personnel changes in the park management (in common with many developing countries), and by the lack of legal clarity over issues relating to transfers of birds.

Meanwhile, other institutions have taken the opportunity to capitalise on the beauty of the Bali Starling. Along the north coast of Bali, inside the park boundary but within the grounds of the Monsoon Forest Resort, a 'soft release' programme has begun. Birds are held in a very secure site, with food, water and suitable nest-boxes provided. They are monitored when they come back twice a day for food. Three other resorts in the same area are supposedly following suit (P. Jepson verbally 2012). Moreover, across the water on the little island of Nusa Penida and outside the species's known range, the Bali-based Begawan Foundation has established a free-flying population through a release programme that began in July 2006 (Dijkman 2007). Up to the end of 2009 65 Bali Starlings were released on the island (apparently in groups of 4-8, in movable aviaries), and at least 62 chicks are reported to have fledged in the wild up to 2011, so that the population is around 100 birds. The foundation's website announces that birds have even colonised the small inshore resort island of Nusa Lembongan. The project now appears to be divided between Begawan Foundation and the Friends of the National Parks Foundation.

Koln Zoo has supported the Begawan Foundation in this venture by supplying 20 birds from various EAZA institutions to their breeding facilities, but the situation in Europe is not particularly propitious. In 2011 there were around 280 birds in 74 European institutions, with probably the same number again in private hands, but the birds are expensive to keep because they are so aggressive towards other species and need careful management in large multispecies aviaries (which are now very popular in zoos). The demographic structure of this population is currently good but its genetic structure is partly unknown, so managing the population is challenging.

Black-winged Starling

This species, endemic to Java and Bali (with a few records from Lombok), may have suffered from trade pressure elevated by its superficial resemblance to the Bali Starling. Its increasing rarity was only noticed in the late 1990s (BirdLife International 2001), just at a time when an authoritative monograph on the Sturnidae (which assigned the species to the genus Acridotheres) was pronouncing it 'common and widespread on Java and Bali' (Feare & Craig 1998). Soon afterwards, it appeared that the highest numbers encountered in the wild were to be found in the escaped population at Jurong Bird Park in Singapore, where some 80 birds were thought to be present.

BirdingASIA-2012-12-BWS2BirdingASIA-2012-12-BWS3

Images above: (left) Plate 2. Black-winged Starling Sturnus melanopterus tricolor, Baluran NP, Situbondo, East Java, Indonesia, 6 October 2012 (Boas Emmanuel); Plate 3. Black-winged Starling Sturnus melanopterus tertius, Ulu Watu, Bali, Indonesia, 2 July 2009 (James Eaton, Birdtour Asia)

A significant problem for aviculture is that the Black-winged Starling occurs in three fairly distinct subspecies, namely melanopterus in most of Java, with white back, rump and all wing-coverts (Plate 1), tricolor in south-eastern Java, with grey back and black greater wing-coverts (Plate 2), and tertius on Bali, with grey back and rump and all-black wing-coverts (Plate 3). These features are not clinal, and sorting out the subspecies is complicated by the characters of the eastern taxa appearing in the nominotypical as an immature stage. Mees (1996) reported a specimen of tricolor from West Java and had some evidence that it came from an established population of tricolor escapes; possibly in recent years there has been much introgression through such human mediation. In captivity the taxa have certainly become mixed, and the Jurong population unfortunately shows this clearly. Thus the species presents a double challenge: first, keeping it alive; and second, keeping it alive in three pure phenotypes. Given the extreme rarity of birds now - for example, following a recent visit to Bali by members of the TSAWG, it was guesstimated that no more than 100 tertius remain in the wild, all in Bali Barat National Park - the second of these challenges is not yet being fully addressed.

One remarkable dimension to this endeavour is the discovery of a village called Klaten in Central Java where birds of this and other species are bred in large numbers for commercial purposes. A number of birds bred in the village were acquired by Zoologischen Gesellschaft fur Arten- und Populationsschutz e.V. (ZGAP) to be housed at Cikananga Wildlife Centre (CWC), a rescue and conservation organisation run by Resit Sozer at Cikananga in west Java (www.cikanangawildlifecenter.com). CWC has had fair success with the breeding of the species, having learnt much from the Klaten villagers, and by mid-2011 held 131 birds of the nominotypical form. By early 2012 the breeding programme had produced over 200 chicks, with the majority surviving to adulthood.

Such a population, increasing rapidly, could not be sustained in the long term, and a plan was drawn up to release birds at the CWC site where the forest is re-growing in an area surrounded by farmland. After the completion of appropriate veterinary and quarantine protocols coupled with extensive negotiations and discussions with all relevant people - village heads, government officials, teachers and journalists - 25 birds were released in March 2012, and to everyone's surprise and delight a pair with offspring were seen just six weeks later. Despite this success, the agricultural nature of the area means that nest-sites may be in short supply, so nestboxes are being made locally (some villagers are holding nestbox-building workshops under CWC staff guidance) and each box will be 'wardened' by a number of schoolchildren, thus hopefully generating greater local support for the project. Two more reintroduction trials at other sites in West Java are presently being planned. There are virtually no Black-winged Starlings in captivity outside Indonesia, and the TSAWG has been evaluating how and where a population might be established and managed as a back-up to the initiative in Java. It is also seeking to determine what might be done for tricolor and tertius - perhaps the first need being some robust fieldwork to determine their status in the wild [tricolor in Baluran National Park and tertius in Bali Barat National Park). Meanwhile Nusa Penida, to which the species was apparently introduced during a presidential visit in 1986 (Dijkman 2007), remains a further focus of the TSAWG's interest, following reports of birds (albeit with no indication of subspecies) being released there in recent years.

Source

  • Collar, N.J., L. Gardner, D. F. Jeggo, B. Marcordes, A. Owen, T. Pagel, T. Pes, A. Vaidl, R. Wilkinson & R. Wirth (2012) - Conservation breeding and the most threatened birds in Asia, in: BirdingASIA, Nr. 18, December 2012

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