In Australia, the Common Myna is an invasive pest. They are now often the predominant bird in urban areas all along the East coast. In a 2008 popular vote, the bird was named “The Most Important Pest/Problem” in Australia, also earning the nickname “flying rats” due to their scavenging resembling that of rats.
The Common Myna was first introduced to Australia in Victoria between 1863 and 1872 into Melbourne’s market gardens to control insects. The bird is likely to have spread to New South Wales (where it is currently most populous) at around the same time, but documentation is uncertain. The bird was later introduced to Queensland as a predator of grasshoppers and cane beetles; the reasons for its original introduction to Victoria is however, lost in history. Currently, Common Myna populations in Australia are 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 bird can live and breed in a wide range of temperatures, though it thrives in hotter regions. Self-sustaining populations of Common Myna have been found in regions of mean warmest month temperature no less than 23.2°C and mean coldest month temperature no less than -0.4°C, implying that the Common Myna could potentially spread from Sydney northward along the eastern coast to Cairns and westward along the southern coast to Adelaide (though not to Tasmania, Darwin, or across the Great Dividing Range to the arid interior regions).
The Common Myna or Indian Myna (Acridotheres tristis), sometimes spelled Mynah, is a member of the family Sturnidae
Myna bird- native to Asia. An omnivorous open woodland bird with a strong territorial instinct, the Myna has adapted extremely well to urban environments here in Australia and continues to spread.
The Common Myna is readily identified by the brown body, black hooded head and the bare yellow patch behind the eye. The bill and legs are bright yellow. There is a white patch on the outer primaries and the wing lining on the underside is white. The sexes are similar and birds are usually seen in pairs.
The calls includes croaks, squawks, chirps, clicks, whistles and ‘growls’, and the bird often fluffs its feathers and bobs its head in singing. The Common Myna screeches warnings to its mate or other birds in cases of predators in proximity or when its about to take off flying.
Common Mynas are believed to pair for life. They breed through much of the year depending on the location, building their nest in a hole in a tree or wall.
The normal clutch size is 4–6 eggs. The average size of the egg is 30.8 x 21.99 mm. The incubation period is 17 to 18 days and fledging period is 22 to 24 days. Nesting material used by mynas include twigs, roots, tow and rubbish. Mynas have been known to use tissue paper, tin foil and sloughed off snake-skin.
The Common Myna uses the nests of most Australian native birds, parakeets, etc. and easily takes to nest boxes; it has been recorded evicting the chicks of previously nesting pairs by holding them in the beak and later sometimes not even using the emptied nest boxes. This aggressive behavior is considered to contribute to its success as an invasive species.
Like most starlings, the Common Myna is omnivorous. It feeds on insects, arachnids, crustaceans, reptiles, small mammals, seeds, grain and fruits and discarded waste from human habitation. It forages on the ground among grass for insects, and especially for grasshoppers, from which it gets the generic name Acridotheres, “grasshopper hunter”. It however feeds on a wide range of insects, mostly picked from the ground. It is a cross-pollinator of flowers such as Salmalia and Erythrina. It walks on the ground with occasional hops and is an opportunistic feeder on the insects disturbed by grazing cattle as well as fired grass fields.
Common Mynas roost communally throughout the year, either in pure or mixed flocks with European Starlings. The roost population can range from less than one hundred to thousands. The time of arrival of Mynas at the roost starts before and ends just after sunset. The mynas depart before sunrise. The time and timespan of arrival and departure, time taken for final settlement at the roost, duration of communal sleep, flock size and population vary seasonally.
The function of communal roosting is to synchronise various social activities, avoid predators, exchange information about food sources.
Communal displays (pre-roosting and post-roosting) comprise of aerial maneuvers which are exhibited in the pre-breeding season (October to March). It is assumed that this behavior is related to pair formation.
The Common Myna thrives in urban and suburban environments; in Canberra, for instance, 110 Common Mynas were released between 1968 and 1971. By 1991, Common Myna population density in Canberra averaged 15 birds per square kilometer. Only three years later, a second study found an average population density of 75 birds per square kilometer in the same area.
The bird likely owes its success in the urban and suburban settings of Melbourne, Sydney and Canberra to its evolutionary origins; having evolved in the open woodlands of India, the Common Myna is pre-adapted to habitats with tall vertical structures and little to no vegetative ground cover, features characteristic of city streets and urban nature preserves.
The Common Myna (along with European Starlings, House Sparrows, and feral Rock Pigeons) is a nuisance to city buildings; its nests block gutters and drainpipes, causing water damage to building exteriors.
The IUCN declared this myna as one of the only three birds among the world’s 100 worst invasive species. (Other two invasive birds being Red-vented bulbul and European Starling) It has been introduced widely elsewhere, including adjacent areas in Southeast Asia, Madagascar, the Middle East, South Africa, Israel, North America, Europe, Australia, New Zealand and various oceanic islands, including a very prominent population in Hawaii.
The Common Myna is a pest in South Africa, North America, the Middle East, Australia, New Zealand and many Pacific islands. It is particularly problematic in Australia.
Being such a widespread and common species, damage control is best achieved by action targeted to problem areas. Wide-scale population reduction is unlikely with currently available methods. Exclusion by netting to deny access to nesting and roosting areas is the most effective control method. Shock track installed to all ledges and parapets to stop birds from roosting.
Shooting and scare guns have only short term benefits at best with the birds rapidly adapting to the intrusion.