Native to the islands of Bali and Java in Indonesia1, the Javan myna, scientifically known as Acridotheres javanicus, belongs to the family Sturnidae, a diverse group of passerine birds — birds characterised by their perching behaviour.2 Javan mynas are expert vocalists, using a wide range of trills, whistles and caws to communicate, prompting their capture and trade as songbirds. Through this songbird trade, A. javanicus was introduced into Singapore around 1920.3 Escaped or released pet mynas then established a population which, over the years, eventually burgeoned to over a hundred thousand individuals.4 In modern Singapore, the avians are often observed foraging and picking off discarded or unattended food in residential districts, food centres and other urban areas. Via a similar process, the Javan myna was introduced into other countries in Southeast Asia including Vietnam, Thailand, Malaysia and the other islands of Indonesia and has become a ubiquitous feature of the urban landscapes of these places.5 Though their calls and songs might once have been considered pleasant, they are now associated with headache-inducing, sleep-depriving, raucous cacophonies, particularly in areas where they congregate.6

The success of the Javan myna in Singapore stands in stark contrast to its plight in its native range. In Bali and Java, the Javan myna faces a declining population due to habitat destruction and poaching affording them an IUCN Red List of Threatened Species classification of 'vulnerable'. Only 2,500 to 9,999 Javan mynas are extant in their native ranges in Bali and Java.7 In sharp contrast, the Javan myna has thrived in the urban environment of Singapore, with an average estimated population of 139,000 individuals in the year 2000.8

Javan mynas have become a familiar sight in Singapore, perching on trees and buildings, and their distinctive calls can be heard throughout the city. The main reason for the Javan mynas’ success, is that they are highly adaptable and are opportunistic feeders, consuming a variety of foods including fruits, insects, small vertebrates, and human leftovers. Like many urban-adapted animals, Javan mynas are not only extremely tolerant of humans but are bold enough to feed and forage near humans, leading to them being a common sight in food centres and other areas where food waste is abundant. Their boldness also enables them to access other ephemeral food sources present within urban districts.9 Javan mynas are reportedly unafraid to steal food from kitchens or raid the food bowls of pets.10 In foraging, the mynas also exhibit a measure of intelligence. Some have learned to associate the gardening activities of humans with the displacement of subterranean arthropods like millipedes and worms and have taken to congregating around gardeners for an easy meal.11

The Javan mynas' social nature further enables them to survive the perils of urban predators. The birds commonly engage in foraging and roaming activities in groups of two or more individuals. During these foraging excursions, one myna assumes the role of a lookout while the others feed. This cooperative behaviour ensures the safety of the group as the sentinel myna remains vigilant for potential dangers.12 If a predator approaches, such as a house cat, the sentinel myna emits loud calls to alert the group, prompting a coordinated escape. In some cases, Javan myna scouts have been observed following and even harassing house cats, constantly calling out to keep other mynas aware of their location.13

This cooperative behaviour provides an important defensive measure against urban predators. Around the world, domestic cats kill an estimated 1.3–4.0 billion birds annually and are responsible for the extinction and endangerment of numerous bird species in various regions.14 With domestic and stray cats being common sight in urban areas like Singapore, the ability of Javan mynas to defend themselves from cat predation undoubtedly allows them to perform better than their avian counterparts in urban environments.

Interestingly, the current daring and aggressive behaviour exhibited by Javan mynas in Singapore was not always the case. Before the 1970s, the common mynah was the dominant myna species associated with Singapore's urban landscape. Ornithologists considered the common myna “bold”.15 The Javan myna, on the other hand, was described as shy and averse to humans and was largely observed in the suburbs.16 However, over time, the Javan mynas in Singapore have developed a tolerance for human presence and have taken over the urban environment, displacing and outcompeting the common mynah.17 Today, the territories of the two species in Singapore have been flipped; the old urban haunts of the common myna have been taken over by their Javan counterparts and the common myna have been relegated to rural suburbs.18

The story of the common myna traces a remarkable similarity to that of its Javan competitor. Where the common myna has been displaced by the more aggressive Javan myna in Singapore, they represent huge invasive pests in numerous other regions such as Australia, New Zealand and Hawaii.19 In Australia for example, the common myna poses a massive threat to native endangered bird species by competing for limited roosting spots and parasitising their nests.20 In this, the common myna ironically perpetuates the plight it suffers in Singapore. Both birds are imperilled in their native range yet proliferate at the expense of other biodiversity in their introduced habitats.

More Than a Myna Problem

The Javan myna’s adaptability to urban settings has allowed them to multiply to pestilent levels, affecting the nation’s human and non-human residents. The communal roosting behaviour of the Javan myna has become a source of disruption and inconvenience in various areas. The number of individual mynas that gather at a single roost tree can reach into the hundreds, creating a chorus of collective calls. The resulting cacophonies are not only irritating but often pose a genuine nuisance to the well-being of local residents.21 22 In places like Potong Pasir, the early morning and evening hours are often disturbed by the piercing calls of these myna birds.23 Reportedly, the calls can get so loud as to drown out even the sounds from television sets.24 The morning cacophony robs residents of precious rest, while attempts to unwind in the evening are thwarted as the mynas return to their roosts and their calls reach a crescendo.

The prevalence of Javan mynas in food centres also brings about its own set of problems, particularly in terms of hygiene. Their droppings, which are abundant due to the large numbers congregating, pose a cleanliness hazard. The accumulation of myna droppings is not only unsightly, but also raises concerns about the spread of diseases.25

At the same time, the biodiversity of Singapore is also affected. The aggressive disposition of A. javanicus affords them the ability to strong-arm and ‘bully’ shier, less-aggressive native birds from resources and roosts.26 While the common myna is a prominent example, ornithologists speculate that the reduction in population of other native birds, like the Oriental Magpie Robin, could be caused by the Javan myna as well.27

A Decades-long Battle

The management of Javan mynas in Singapore has been a longstanding issue, marked by conflict and varying perceptions. These birds have been widely regarded as a threat to public health and well-being, firmly establishing their status as pests in the collective consciousness of residents. For many years, the Javan myna, along with five other bird species, was classified as an "outlaw" under Singapore's Wild Animals and Birds Act of 2000, exempting them from the country's stringent wildlife protection laws.28 However, this exclusion was eventually repealed in 2020, making it now a lawful offence for a member of the public to harm the birds.29

The responsibility of implementing myna population control measures currently falls largely under the Agri-food and Veterinary Authority of Singapore (AVA).30 Over the years, several stop-gap measures have been employed to manage mynah populations. One common approach involves pruning the crowns of trees in residential areas to reduce the availability of favourable nesting sites for mynas.31 32 Additionally, various experimental methods have been explored, such as using lasers and chemical repellents to deter the birds from roosting.33 34 Businesses along Singapore's popular shopping district, Orchard Road, even considered releasing hawks, a natural predator of mynas, as a means of deterrence.35 More experimental methods, such as passing electrical currents through the roots of roost trees to disrupt the mynas' roosting behaviour, have also been tested. Unfortunately, most of these measures have proven ineffective in producing sustainable long-term results.36 The population of Javan myna, and consequently, the complaints associated with their proliferation remains at an all time high.

A controversial yet often employed method of the management of many invasive species around the world is culling. The Javan mynas are not exempt. In the afore-mentioned Potong Pasir area, authorities have trialled the use of a giant net to trap mynas roosting and cull them via carbon dioxide gassing.37 However, such culling measures have sparked significant controversy and criticism. Registered animal welfare charity, Animal Concerns and Research Society (ACRES) have expressed concerns regarding AVA’s measures on grounds of morality and practical effectiveness.38 N Sivasothi, a renowned local professor in biological sciences at the National University of Singapore (NUS), similarly expressed disappointment in AVA's measures.39 Detractors argue that culling fails to address the root causes of the myna population increase, which many attribute to current landscaping practices and inadequate food waste management.40 41 Indeed ACRES allegedly observed that the culling of certain pest species in the past only reduced competition for other pest species, thus leading to the population increase of other pests.42

The issue of managing Javan myna populations in Singapore is far from straightforward. While robust waste management practices may play a role in limiting the proliferation of urban pests 43, it is clear that current measures have not proven effective for managing Javan myna populations. Unlike other avian pests such as crows, the mynas seem to thrive despite the authorities’ best efforts. The complex ecology of built environments presents a multitude of factors contributing to the propagation of myna populations. Ultimately, the management of Javan myna populations in Singapore serves as a microcosm of the larger global challenge of navigating the nature-urban interface. Like many other countries, Singapore is gearing for increased integration between nature and the urban environment. In this pursuit, conflicts between societal needs and the natural world inevitably arise, posing difficult questions about what integration entails. Should we only admit aesthetically pleasing aspects of the environment into our communities? Should any natural features and fauna that prove inconvenient to urban life be neutered and removed? These questions perhaps lead to a more fundamental query about the values we place on the natural world and how we act and manage ourselves and the environment that is consistent with these values.

  1. BirdLife International, "IUCN Red List of Threatened Species: Acridotheres Javanicus," IUCN Red List of Threatened Species, June 2, 2020, https://www.iucnredlist.org/en. ↩

  2. C. Jonathan Schmitt and Scott V. Edwards, "Passerine Birds," Current Biology 32, no. 20 (October 2022): R1149. ↩

  3. Haw Chuan Lim, Navjot S. Sodhi, Barry W. Brook, and Malcom C. K. Soh, "Undesirable Aliens: Factors Determining the Distribution of Three Invasive Bird Species in Singapore," _Journal of Tropical Ecology _19, no. 6 (November 2003): 689, https://doi.org/10.1017/S0266467403006084. ↩

  4. Lim et al., "Undesirable Aliens," 690. ↩

  5. Lim Yi Lin and Jonathan Kit Ian Ho, "Acridotheres Javanicus - Javan Myna - Taxo4254," Wiki.nus, August 21, 2020, https://wiki.nus.edu.sg/display/TAX/Acridotheres+javanicus+-+Javan+Myna. ↩

  6. Cynthia Choo, "'Cacophony' of Mynah Birds a Headache for Some Potong Pasir Residents," TODAY, August 9, 2018, https://www.todayonline.com/singapore/cacophony-mynah-birds-headache-some-potong-pasir-residents. ↩

  7. "Javan Myna (Acridotheres Javanicus) - BirdLife Species Factsheet," accessed May 18, 2023, http://datazone.birdlife.org/species/factsheet/javan-myna-acridotheres-javanicus/text. ↩

  8. Lim et al., "Undesirable Aliens," 690. ↩

  9. Kang Nee, "Comparative Behavioural Ecology of the Mynas, Acridotheres Tristis (Linnaeus) and A. Javanicus (Cabanis) in Singapore," PhD diss., (National University of Singapore, 1990), 99-100. ↩

  10. YC Wee, "Cats, Dogs, Squirrels and Javan Mynas," Bird Ecology Study Group, November 6, 2006, https://besgroup.org/2006/11/06/cats-dogs-squirrels-and-javan-mynas/. ↩

  11. YC Wee, "How the Urban Jungle Drives Evolution: 2. Javan Mynas," Bird Ecology Study Group, August 7, 2018, https://besgroup.org/2018/08/07/how-the-urban-jungle-drives-evolution-2-javan-mynas/ ↩

  12. Wee, "Cats, Dogs, Squirrels and Javan Mynas." ↩

  13. Lim and Ho, "Acridotheres Javanicus - Javan Myna - Taxo4254." ↩

  14. Scott Loss, Tom Will, & Peter Marra, "The impact of free-ranging domestic cats on wildlife of the United States," _Nat Commun _ 4, 1396 (2013): 2, https://doi.org/10.1038/ncomms2380. ↩

  15. Peter Ward, "Origin of the Avifauna of Urban and Suburban Singapore," Ibis 110, no. 3 (3 April 2008): 246, https://doi.org/10.1111/j.1474-919X.1968.tb00036.x. ↩

  16. Ward, "Origin of the Avifauna of Urban and Suburban Singapore," 246. ↩

  17. Lim et al., "Undesirable Aliens." ↩

  18. Lim and Ho, "Acridotheres Javanicus - Javan Myna - Taxo4254." ↩

  19. K. Atsawawaranunt, K.M. Ewart, R.E. Major et al., "Tracing the introduction of the invasive common myna using population genomics," Heredity 131 (2023): 56, https://doi.org/10.1038/s41437-023-00621-w. ↩

  20. Government of Western Australia, "Common myna: animal pest alert," accessed September 4, 2023, https://www.agric.wa.gov.au/birds/common-myna-animal-pest-alert. ↩

  21. Charlotte A.-M. Yap, Navjot S. Sodhi, and Barry W. Brook, "Roost Characteristics of Invasive Mynas in Singapore," The Journal of Wildlife Management 66, no. 4 (October 2002): 1118, https://doi.org/10.2307/3802943. ↩

  22. Choo, "'Cacophony' of Mynah Birds a Headache for Some Potong Pasir Residents." ↩

  23. Choo, "'Cacophony' of Mynah Birds a Headache for Some Potong Pasir Residents." ↩

  24. Choo, "'Cacophony' of Mynah Birds a Headache for Some Potong Pasir Residents." ↩

  25. Ministry of National Development (MND), "Written Answer by Ministry of National Development on Noise Disturbance by Birds in Potong Pasir," accessed May 13, 2023, https://www.mnd.gov.sg/newsroom/parliament-matters/q-as/view/written-answer-by-ministry-of-national-development-on-noise-disturbance-by-birds-in-potong-pasir. ↩

  26. MND, "Written Answer by Ministry of National Development on Noise Disturbance by Birds in Potong Pasir." ↩

  27. Ding Li Yong, "The Javan Myna – Mixed Fortunes of a Familiar Stranger," Singapore Bird Group, June 5, 2015, https://singaporebirdgroup.wordpress.com/2015/06/05/the-javan-myna-mixed-fortunes-of-a-familiar-stranger/. ↩

  28. Singapore Parliament, Wild Animals and Birds Act (CHAPTER 351), https://sso.agc.gov.sg:5443/Acts-Supp/18-2020/Published/20200506?DocDate=20200506. ↩

  29. Singapore Statutes Online, "Wild Animals and Birds (Amendment) Act 2020," https://sso.agc.gov.sg:5443/Acts-Supp/18-2020/Published/20200506?DocDate=20200506. ↩

  30. MND, "Written Answer by Ministry of National Development on Noise Disturbance by Birds in Potong Pasir." ↩

  31. MND, "Written Answer by Ministry of National Development on Noise Disturbance by Birds in Potong Pasir." ↩

  32. Rachel Au-Yong, "Mynah Birds, Major Headache for Jurong West Residents," The Straits Times, August 8, 2013, https://www.straitstimes.com/singapore/mynah-birds-major-headache-for-jurong-west-residents. ↩

  33. MND, "Written Answer by Ministry of National Development on Noise Disturbance by Birds in Potong Pasir." ↩

  34. Choo, "'Cacophony' of Mynah Birds a Headache for Some Potong Pasir Residents." ↩

  35. AFP News, "Hawks to Patrol Singapore Shopping District-report," Yahoo News, October 13, 2011, https://sg.news.yahoo.com/hawks-patrol-singapore-shopping-district-report-160529467.html. ↩

  36. MND, "Written Answer by Ministry of National Development on Noise Disturbance by Birds in Potong Pasir." ↩

  37. Zhangxin Zheng, "Acres Questions Effectiveness of Culling after Giant Trap Set up in Potong Pasir to Cull Mynas," Mothership, December 31, 2018, https://mothership.sg/2018/12/acres-mynas-trap-potong-pasir-ava/. ↩

  38. ACRES: Animal Concerns Research and Education Society (Singapore), "HAS CULLING MYNAHS BEEN SCIENTIFICALLY PROVEN TO WORK EFFECTIVELY?," December 29, 2018, Facebook Post, https://www.facebook.com/ACRESasia/posts/has-culling-mynahs-been-scientifically-proven-to-work-effectively-thats-the-ques/10156342832356523/. ↩

  39. Zheng, "Acres Questions Effectiveness of Culling after Giant Trap Set up in Potong Pasir to Cull Mynas." ↩

  40. ACRES, "HAS CULLING MYNAHS BEEN SCIENTIFICALLY PROVEN TO WORK EFFECTIVELY?" ↩

  41. Zheng, "Acres Questions Effectiveness of Culling after Giant Trap Set up in Potong Pasir to Cull Mynas." ↩

  42. Zheng, "Acres Questions Effectiveness of Culling after Giant Trap Set up in Potong Pasir to Cull Mynas." ↩

  43. Kwek Yan Chong, Siyang Teo, Buddhima Kurukulasuriya and Yi Fei Chung, "Decadal Changes in Urban Bird Abundance in Singapore," The Raffles Bulletin of Zoology 25 (June 2012): 187. ↩