T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Mynah (Acridotheres tristis)

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Sturnidae
Genera: Acridotheres
Species: Tristis
Scientific name: Acridotheres tristis
Common name: Mynah

The mynah was introduced from Asia. It is a 24 cm, 125 g. It is a cheeky brown bird with a jaunty walk. Adults are cinnamon brown with glossy black head and neck, white undertail and underwing; yellow legs, bill and a bare patch of skin near the eye. Sexes are alike. Juveniles have a dark brown head, paler bill and facial skin. In-flight prominent white patches are on show on the wings, and white-tipped tail can be seen.
Mynahs 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. They will nest in chimneys as seen in photos below.

Breeding occurs Oct-Mar. 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 includes twigs, roots, tow and rubbish. Mynahs have been known to use tissue paper, tin foil.

The mynah uses the nests of other birds. 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 nests. This aggressive behaviour is considered to contribute to its success as an invasive species.

They roost communally all year, largest in winter; small flocks converge at dusk and depart at dawn. They feed mainly on the ground, often at roadsides. 
The mynah 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.
Their voice is jangling and the song is a rapid medley of raucous gurgling, chattering and bell-like notes. It habits parks, gardens, orchards and farmland, sometimes on forest margins. Call of the Mynah

It is an Invasive species.
The IUCN (International Union for Conservation of Nature) declared myna as one of the only three birds among the world's 100 worst invasive species. It has been introduced widely including adjacent areas in Southeast Asia, Madagascar, the Middle East, South Africa, Israel, North America, Europe, and Australia, New Zealand and various oceanic islands, including a very prominent population in Hawaii.

The threat to native birds.
The mynah 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 mynah 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 mynah to displace many breeding pairs of native birds, thereby reducing their reproductive success. Where mynas gather in large numbers to feed on stock food, crops or fruit, they cause considerable economic loss

The sharp talons of a Mynah 

A mynah's nest blocking a chimney flue

Nest removed from the flue

Thanks to Wikipedia for text and information     https://creativecommons.org/licenses/by-sa/3.0/