,
Samoa The IUCN declared the common myna as one of only three birds among the
world's 100 worst invasive species (the other two being the
red-vented bulbul and the
common starling). The French introduced it in the 18th century from
Pondicherry to
Mauritius with the aim of controlling insects, even levying a fine on anyone persecuting the bird. It has since been introduced widely elsewhere, including adjacent areas in
Southeast Asia,
Madagascar, the
Middle East,
South Africa, the
United States,
Argentina,
Germany, Spain and Portugal, the
United Kingdom,
Australia,
New Zealand and various oceanic islands in the Indian and Pacific Oceans, including prominent populations in
Fiji and
Hawaii. The common myna is regarded as a pest in South Africa, North America, the Middle East, Australia, New Zealand and many Pacific islands. It is particularly problematic in Australia. Several methods have been tried to control the bird's numbers and protect native species.
Australia In
Australia, the common myna is an
invasive pest. They are often the predominant bird in urban areas along the whole
east coast. In a 2008 popular vote, the bird was named "The Most Important Pest/Problem" in Australia. They have earned the nickname "flying rats", due to their numbers and their scavenging behaviour. They are also known as "the
cane toad of the sky". The common myna was first introduced to Australia between 1863 and 1872, in
Victoria, to control insects in the market gardens of
Melbourne. At about the same time, the bird is likely to have spread to
New South Wales, where it is currently most populous, but documentation is uncertain. The bird was later introduced to Queensland as a predator of
grasshoppers and
cane beetles. Common myna populations in Australia are now concentrated along the eastern coast around
Sydney and its surrounding suburbs, with sparser populations in Victoria and a few isolated communities in
Queensland. During 2009, several municipal councils in New South Wales began trials of catching myna birds in an effort to reduce numbers. The myna can live and breed in a wide range of temperatures, ranging from the frosty winters of
Canberra to the tropical climate of
Cairns. Self-sustaining populations have been found in regions with a mean monthly highest temperature no less than and a mean monthly lowest temperature no less than , implying that the common myna could spread from Sydney northwards along the eastern coast to Cairns, and westwards along the southern coast to
Adelaide, but not to
Tasmania,
Darwin, or the arid outback regions.
Europe In 2019, common mynas were added to the
List of Invasive Alien Species of Union concern. They have established in Spain and Portugal and were introduced to France, where they occasionally bred.
New Zealand The common myna was introduced to both the North Island and South Island of New Zealand in the 1870s. However, the cooler summer temperatures in the South Island appear to have impeded the breeding success rate of the southern populations, preventing the proliferation of the species, which was largely non-existent there by the 1890s. In contrast, the North Island population was able to breed more successfully and large portions of the North Island are now populated. However, in the southern reaches of the North Island, the cooler summer temperatures, like those of the South Island, have prevented the establishment of large myna populations. Since the 1950s, mynas have spread northwards and presently inhabit beyond the Waikato region, leading to a majority of its successful population thriving upon lower latitude regions due to the warmer climate.
South Africa In South Africa, where it escaped into the wild in 1902, it has become very common and its distribution is greater where human populations are greater or where there is more human disturbance. The bird is also notorious for being a pest, kicking other birds out of their nests and killing their young due to the myna's strong territorial instinct. It is considered somewhat of a major pest and disturbance of the natural habitat; as a result, it has been declared an invasive species, requiring it to be controlled. Morphological studies show that the process of spatial sorting is at work on the range expansion of
A. tristis in South Africa. Dispersal-relevant traits are significantly correlated with distance from the range core, with strong sexual dimorphism, indicative of sex-biased dispersal. Morphological variations are significant in wing and head traits of females, suggesting females as the primary dispersing sex. In contrast, traits not related to dispersal such as those associated with foraging show no signs of spatial sorting but are significantly affected by environmental variables such as vegetation and intensity of urbanisation. To study the
invasion genetics and landscape-scale dynamics of
A. tristis in South Africa, scientists have recently developed 16 polymorphic nuclear microsatellite markers using the
next generation sequencing (NGS) approach.
United States In Hawaii, it is out-competing many native birds for food and nesting areas.
Israel In the late 1990s a few myna birds had escaped or were released from captivity in
Tel-Aviv. Since then its wild population had exploded, and in a birding survey in 2024 it was found to be the second most observed bird in Israel. It is presumed to be responsible for the decline in the populations of some of Israel's common native birds.
Effect on ecosystems and humans Threat to native birds The common myna is a hollow-nesting species; that is, it nests and breeds in protected hollows found either naturally in trees or artificially on buildings (for example, recessed windowsills or low eaves). Compared to native hollow-nesting species, the common myna is extremely aggressive, and breeding males will actively defend areas ranging up to 0.83
hectares in size (though males in densely populated urban settings tend to only defend the area immediately surrounding their nests). This aggressiveness has enabled the common myna to displace many breeding pairs of native hollow-nesters, thereby reducing their reproductive success. In Australia, their aggressiveness has enabled them to chase native birds as large as
galahs out of their nests. The common myna is also known to maintain up to two
roosts simultaneously; a temporary summer roost close to a breeding site (where the entire local male community sleeps during the summer, the period of highest aggression), and a permanent all-year roost where the female broods and incubates overnight. Both male and female common mynas will fiercely protect both roosts at all times, leading to further exclusion of native birds.
Threat to crops and pasture The common myna (which feeds mostly on ground-dwelling
insects, tropical fruits such as grapes, plums and some
berries and, in urban areas, discarded human food) poses a serious threat to Australian
blueberry crops, though its main threat is to native bird species. In Hawaii, where the common myna was introduced to control pest
armyworms and
cutworms in
sugarcane crops, the bird has helped to spread the robust
Lantana camara weed across the islands' open
grasslands. It also has been recorded as the fourth-ranking avian pest in the fruit industry by a 2004 survey of the Hawaiian Farm Bureau and the sixth in number of complaints of avian pests overall. Common mynas can cause considerable damage to ripening fruit, particularly grapes, but also figs, apples, pears, strawberries, blueberries, guava, mangoes and breadfruit. Cereal crops such as maize, wheat and rice are susceptible where they occur near urban areas. Roosting and nesting commensal with humans create aesthetic and health concerns. Common mynas are known to carry avian malaria and exotic parasites such as the
Ornithonyssus bursia mite, which can cause dermatitis in humans. The common myna can help spread agricultural weeds: for example, it spreads the seeds of
Lantana camara, which has been classed as a Weed of National Significance because of its invasiveness. Common mynas are regularly observed to usurp nests and hollows, destroy the eggs and kill the young of native bird species, including seabirds and parrots. There is evidence that common mynas have killed small land mammals such as mice, squirrels and possums, but further research on these occurrences is under consideration.
Control The common myna, being a major agricultural pest and posing a threat to native species in non-native countries, is controlled by various factors. Mynas are either killed or chased away as control. Poison, The bird called
śārikā ( or शारिका) most often refers to the common myna, though there are other candidates. ==Gallery==