Our recent article on the Red-billed Quelea in Punggol generated much debate in local conservation circles and the media about how invasive birds can impact our native biodiversity. Sitting at the crossroads of trade in Asia, Singapore is inevitably also a hub for the pet industry and sets the stage for the sale of many thousands of birds, mammals and reptiles, not to mention the less visible transit of many more animals from the region destined for markets further afield. Every now and then, some of these animals find their way into our wilds, either from accidental or deliberate releases by people.
While there is no immediate danger of the quelea being established here, one does not need to look far to find a non-native bird that has colonised Singapore’s landscapes in a big way, and now regularly feature in our national newspapers for all the wrong reasons. Today, the familiar Javan Myna is probably our commonest resident bird, has topped the counts of almost all our bird censuses in recent years, and has probably also annoyed more people here than any other bird species (by their large noisy roosts). While there is limited observational evidence of how Javan Mynas have competed with other native species like the Common Myna and Oriental Magpie Robin, some conservationists believe that the decline of both species may be associated with the rise of the Javan Myna. Not surprisingly, there is considerable overlap between the habitats used by the Javan Myna and these two species, leading to competition for resources.
A declining native
While the Javan Myna has thrived in its non-native distribution, particularly in the Malay Peninsula (including Singapore), parts of Sarawak (e.g. Kuching), Sabah (e.g. Tawau), and increasingly does so in northern Sulawesi (e.g. Manado), not many people are aware of the massive declines suffered in its native range of Java and Bali. A massive demand for Javan Mynas and other wild starlings (e.g. Asian Pied Starling) in the Indonesian pet trade has taken its toll on the indigenous population of this species. In seven visits to West Java and Bali since 2003, I have only encountered the mynas twice, and only as singles or pairs, but never in the big flocks seen in Singapore. Some Indonesian colleagues casually remarked that the only Javan Mynas left on Java are the poor few lingering on in the national parks or nature reserves. At the same time, I have seen it on sale in large numbers in bird shops in the Indonesian cities of Jakarta, Bogor, Palu and Padang. In some bird shops in Bogor for instance, single Javan Mynas may fetch over 300,000 IRP (30 SGD) or more.
A myna difference
One of the benefits of being a naturalist living in two cities is that one can make comparisons of the animal life of both, and see how it can change with time. In my childhood days, I spent much time in Kuala Lumpur’s outskirts, as much as I did in Singapore and so had an opportunity to observe birds in two somewhat similar urban settings 350 km apart. It was interesting then to note that mynas I observed in my school grounds in 1996 were mostly the ‘black’ ones (i.e. Javan Myna) while those in my KL backyard were the ‘brown’ ones (i.e. Common Myna). The differences in voices meant that it was not too difficult to identify either species’ presence even when the mynas were not seen. So it intrigued me one day in 2000 when I heard a familiar screeching sound in a neighborhood playing field in Kuala Lumpur – that of a Javan Myna! A quick search found one Javan Myna in a large group of 20 Common Mynas. In the 15 years that followed, Javan Mynas have became more ubiquitous in my estate and in my last visit in 2014, large groups can now be seen all over Kuala Lumpur and the Klang Valley.
Looking back in time with an ecologist’s lenses, it becomes quite clear that the spread of the Javan Myna from Singapore into Peninsular Malaysia has been rapid even though the exact time frames cannot be determined due to patchy documentation by birdwatchers for abundant bird species. Javan Mynas are now common across Johor north to Kuala Lumpur and large flocks can now be seen commuting the Straits of Johor daily. Documentation from other birdwatchers in Malaysia showed that the Javan Myna has spread to as far north as central Perak and continues to expand its range, aided possibly by large areas of deforested countryside made available to them. In its march north, novel ecological problems are created, because species that have never interacted with Javan Mynas will now have to. Native starlings of open country like the Common and Jungle Mynas are of course now faced with an aggressive competitor, and may decline in the long term. Further north, the White-vented Myna may soon cross paths with its southern, non-native relative, with predictable consequences.
The spread of the Javan Myna up the Malay Peninsula, as revealed by the observations collected by birdwatchers in Malaysia and Singapore, is possibly one of the most striking changes in avifauna in the region in recent years, made more so by the ubiquity and conspicuousness of these birds. While the resources to manage the invasion of this species was probably not available many decades ago when it was more manageable, the rapid range expansion of the Javan Myna is a clear reminder than an invasive animal from a climatically different part of Southeast Asia (i.e. monsoonal and drier Java), has the potential to spread far and wide, especially if it is facilitated by other broader landscape changes caused by deforestation, urbanisation or even climate change. On the other hand, the declines in its native Java reflects the mixed fortunes faced by the Javan Myna, and poses interesting questions for conservationists. It is possible, and plausible that the invasive populations of this species in Singapore or Malaysia, can be used to repopulate areas in Java or Bali where it has been hunted out, or that these populations can be used to alleviate the pressure on wild populations by the Indonesian pet trade. Whatever the case, the Javan Myna story poses an interesting challenge for conservationists in a modern setting where innovative solutions are needed to conserve species effectively.
Cover Photo: “Javan Mynas on a tree trunk” by Low Choon How