The Asian Glossy Starling (Aplonis panayensis) is one of Southeast Asia’s most visible and vocal birds, a stocky, iridescent black starling found from the Philippines and Borneo through Peninsular Malaysia, Indonesia, and into parts of mainland Southeast Asia. It has adapted so thoroughly to human settlements that most people in its range encounter it not in forest but on rooftops, in city parks, and clustered on power lines. Recent genetic work suggests what we call “the Asian Glossy Starling” may actually be more than one species, adding an unexpected layer of complexity to a bird many locals take for granted.
How to Recognize One
Adults are entirely dark, with plumage that gleams deep green in direct light and can look almost purplish-black in shade. The iridescence covers the head, back, wings, and breast, making the bird look uniformly glossy from any angle. The eyes are a distinctive bright red, easily visible even at a distance and one of the fastest identification features in the field. The bill is short and slightly curved, suited for gripping fruit. Males and females look essentially alike once fully mature, which is unusual among starlings generally but typical of the Aplonis group.
Juveniles, on the other hand, are strikingly different from adults. Young birds carry heavily streaked white-and-dark-brown underparts with brownish upperparts, and their eyes are dark rather than red. Birdwatchers unfamiliar with the species sometimes mistake juvenile Asian Glossy Starlings for a completely different bird. The transition from juvenile to adult plumage happens gradually over the first year or so, with birds passing through a patchy intermediate stage where dark glossy feathers appear among the streaked brown ones.
Range and Preferred Habitats
The species spans a huge area across the Indo-Malayan region. Its native range covers the Philippines, Borneo, Sumatra, Java, Sulawesi, Peninsular Malaysia, and parts of mainland Southeast Asia including southern Myanmar, Thailand, and possibly into the Indian subcontinent at its western edge. Across this range, the bird occupies lowland and lower montane zones, generally keeping below about 1,000 meters in elevation. It favors forest edges, secondary growth, plantations, and increasingly, urban areas.
Beyond its native territory, the species has established itself as an introduced breeder in places where it was either released or escaped from captivity. In southern Taiwan, for instance, the species has been present since around 1990, and breeding records have been documented in cities and counties from Yilan in the northeast to Pingtung in the south over the following two decades.1Semantic Scholar. Breeding Biology of the Invasive Asian Glossy Starling (Aplonis panayensis) in Urban Parks of Kaohsiung City, Southern Taiwan This pattern of quiet colonization in human-dominated landscapes is typical: the bird slips into a city, finds nesting cavities in buildings, and builds a self-sustaining population before anyone pays much attention.
A Species That May Actually Be Several
One of the more surprising developments in recent ornithology concerns whether “Asian Glossy Starling” even refers to a single species. Genetic analysis of the broader Aplonis genus, a group of starlings spread across the Pacific and Southeast Asia, has revealed that Aplonis panayensis as traditionally defined is polyphyletic. That means different populations grouped under the same name are not each other’s closest relatives: some are more closely related to other Aplonis species than to each other.
A phylogenetic study that sampled subspecies across the genus found evidence for at least two species-level splits within what is currently called A. panayensis.2PubMed. Phylogeny of Pacific starlings (genus Aplonis) reveals cryptic diversity and diverse biogeographic patterns In practical terms, this means that the bird you see in the Philippines and the bird you see in Borneo or Sumatra, while they look quite similar, may be distinct species that evolved their glossy black appearance independently or diverged long enough ago that lumping them together misrepresents their evolutionary history. The same study found that subspecies-level diversity within the broader Aplonis group has continued accumulating toward the present, meaning geographic isolation across island chains keeps generating new forms. Whether the taxonomic authorities will formally split A. panayensis into multiple species remains to be seen, but the genetic evidence points strongly in that direction.
For the casual birdwatcher, the practical significance is that field guides covering all of Southeast Asia may eventually need to treat island populations as separate species. Range maps might shrink, and regional endemism scores could shift. It also means that conservation assessments based on the entire “species” range could be misleading if one population is actually a distinct, more range-restricted species with a smaller total population.
What They Eat
The Asian Glossy Starling is primarily a frugivore. A dietary study of a roosting population in Peninsular Malaysia found that fruit made up about three-quarters of the diet, with the remaining quarter consisting of animal material such as ants, snails, and beetle larvae.3Sains Malaysiana. The Diet of a Roosting Population of Asian Glossy Starling Aplonis panayensis in Jelebu, Negeri Sembilan, Malaysia The most commonly consumed fruit in that study belonged to Trema orientalis, a fast-growing tree common along roadsides and forest edges. Researchers used DNA barcoding of intact seeds found in droppings to identify plant species, and seven of the nine species they detected were new dietary records for the bird.
This fruit-heavy diet has ecological consequences. As the starlings move between fruiting trees and roost sites, they disperse seeds across the landscape. Species like Trema orientalis are pioneer plants that colonize disturbed ground, so the starlings may help forests regenerate by spreading seeds into clearings, road edges, and abandoned agricultural land. At the same time, in areas where the starling is introduced rather than native, that same seed-dispersal ability could help spread invasive plants.
The animal component of the diet, while small in proportion, broadens the starling’s nutritional base and likely becomes more important during breeding season, when protein demands increase for growing chicks. The flexibility to switch between fruit and invertebrate prey depending on what is available is one reason the species copes so well with human-altered environments, where native fruiting trees may be scarce but insects around refuse or agriculture are plentiful.
Breeding and Nesting
Asian Glossy Starlings are cavity nesters. In forested habitats, they use tree hollows, often old woodpecker holes. In urban areas, they readily exploit gaps in building facades, holes in walls, spaces behind signage, and openings in roof structures. They nest in loose colonies, meaning several pairs may occupy cavities in the same tree or the same stretch of building. Clutch size is typically two to three eggs, which are pale blue or blue-green. Both parents participate in incubation and feeding.
The species’ willingness to nest in artificial structures has been central to its success in cities. Research in Kaohsiung City, Taiwan, documented breeding activity in urban parks where the birds used cavities in buildings and large planted trees as nest sites.4Semantic Scholar. Breeding Biology of the Invasive Asian Glossy Starling (Aplonis panayensis) in Urban Parks of Kaohsiung City, Southern Taiwan The breeding season varies with latitude and rainfall patterns but tends to be prolonged in equatorial populations, where some nesting activity can occur year-round. In more seasonal climates, breeding typically coincides with the wet season, when insect availability peaks and fruit is abundant.
Roosting Flocks and Urban Nuisance
Perhaps the most conspicuous behavior of the Asian Glossy Starling is its communal roosting. Each evening, flocks converge on a shared roost site, often in trees along busy roads or on the ledges and awnings of commercial buildings. Roosts can be enormous. At an industrial estate in East Kalimantan, Indonesia, the birds were identified as the primary nuisance species, congregating in densities that created persistent problems with noise, droppings, and structural fouling. The scale of some urban roosts is hard to overstate: a monitoring effort at an industrial factory in Malaysia recorded a peak population of more than 35,000 birds at the roost site in January 2021, while the lowest count in the same year was still nearly 3,700.5PubMed Central. Efficacy of Several Types of Pest Bird Deterrents and General Trend of Pest Birds at an Industrial Factory
That seasonal swing is telling. Roost populations swell dramatically during the non-breeding period, when birds that were dispersed across nesting territories reconvene. In the Malaysian study, the peak coincided with the northeast monsoon season, when food resources in some areas decline and birds consolidate around reliable roost sites near remaining food sources. The practical result for factory managers, city planners, and homeowners is that starling problems tend to be worst during certain months and somewhat predictable from year to year.
The droppings from these roosts are more than just unsightly. Accumulated bird feces can corrode metal structures, damage paint, create slip hazards on walkways, and produce a strong ammonia odor. For food-processing facilities and manufacturing plants, the contamination risk poses genuine health and safety concerns. This has driven considerable research into deterrent methods.
What Actually Works to Deter Them
A study testing nine different bird deterrent strategies against Asian Glossy Starlings, Barn Swallows, and Pacific Swallows found that several approaches significantly reduced the number of birds perching on targeted spots.6PubMed Central. Efficacy of Several Types of Pest Bird Deterrents and General Trend of Pest Birds at an Industrial Factory Methods that worked included alarm and distress calls broadcast from portable speakers, sonic devices combining broad-spectrum sound frequencies with flashing lights, bird predator models (both moving and static), reflective compact discs, and reflective tapes of varying visibility. Methyl anthranilate, a grape-scented chemical irritant sometimes used as a bird repellent, was also tested.
A few practical lessons emerge from this research. First, deterrents that combine sensory inputs, such as sound plus light, tended to perform well, likely because they are harder for the birds to habituate to. Starlings are intelligent and adaptable, and a single unchanging deterrent, such as a stationary owl decoy, often loses its effect over weeks as the birds learn it poses no real threat. Second, the sheer scale of some roosts means deterrents may push birds to adjacent structures rather than away from a site altogether. This is a common frustration for facility managers: the starlings don’t leave the area, they just move to a neighboring building. Integrated approaches that combine multiple deterrent types and coordinate across a wider area tend to produce better long-term results than any single device.
Physical exclusion, such as netting over vulnerable structures, remains the most reliable option for high-value areas. It prevents access rather than relying on the birds choosing to avoid a spot, which removes the habituation problem entirely. The trade-off is cost and aesthetics. For large industrial facilities, netting entire rooflines or loading bays can be expensive, though the savings from reduced cleaning and damage often justify it over time.
Blood Parasites in Wild Populations
Like most wild birds, Asian Glossy Starlings carry blood parasites. A study of wild-caught birds in Sarawak, Malaysian Borneo, found that roughly half of the individuals sampled were infected with avian Plasmodium, the same genus of parasites responsible for malaria in humans, though the bird-infecting species are different and do not affect people.7BMC Veterinary Research. Prevalence of haemosporidia in Asian Glossy Starling with discovery of misbinding of Haemoproteus-specific primer to Plasmodium genera in Sarawak, Malaysian Borneo Genetic analysis divided the parasites into five distinct lineages, two of which had never been identified before.
The high infection rate raises questions about how the parasites affect the starlings’ health and behavior. In many bird species, chronic Plasmodium infection can reduce body condition, suppress reproductive output, and increase vulnerability to other stressors. However, some species that have coevolved with their parasites for long periods tolerate infection with minimal visible effects. Whether Asian Glossy Starlings fall into the “tolerant host” category or pay a meaningful fitness cost isn’t yet clear.
The Sarawak study also turned up a methodological wrinkle that matters to researchers working on avian blood parasites more broadly. A primer designed to detect only Haemoproteus, a different genus of avian blood parasite, was found to also amplify Plasmodium DNA. This kind of cross-reactivity could lead researchers studying other bird species to misidentify their parasite samples if they rely solely on that primer, potentially inflating the apparent prevalence of Haemoproteus and underestimating Plasmodium in survey datasets.8BMC Veterinary Research. Prevalence of haemosporidia in Asian Glossy Starling with discovery of misbinding of Haemoproteus-specific primer to Plasmodium genera in Sarawak, Malaysian Borneo
Living Alongside Them
For people who share their neighborhoods with Asian Glossy Starlings, the experience is a mixture of appreciation and irritation. The birds are handsome up close, their iridescent plumage catching the light beautifully, and their role in seed dispersal provides a genuine ecological service. They eat pest insects as a secondary food source. They bring a sort of noisy vitality to urban greenspaces that might otherwise feel sterile.
On the other hand, a roost of thousands of starlings on your office building is no one’s idea of pleasant. The noise at dusk and dawn can be remarkable, a cacophony of harsh, squeaky calls that carries over traffic and air conditioning. The droppings coat everything beneath the roost, and cleaning them regularly becomes an ongoing maintenance burden. In tropical climates, the droppings also dry quickly and can become airborne as dust, which isn’t ideal for air quality.
The species’ ongoing range expansion into new cities, both within its native range as urbanization creates new habitat and outside it as introduced populations establish, means more communities will face this coexistence challenge in coming decades. Balancing tolerance for a native bird fulfilling ecological roles with practical management of large roosts in sensitive locations is unlikely to get simpler. The deterrent research being done in Malaysia and Indonesia is exactly the kind of applied ecology that will matter more, not less, as these starlings continue to thrive in the human-built world.