The Common myna (Acridotheres tristis) is a tropical bird with a strong territorial instinct, which has adapted extremely well to urban environments. The range of the Common myna is increasing at such a rapid rate that in 2000 the IUCN Species Survival Commission declared it one of the world's most invasive species and one of only three birds listed among "100 of the World's Worst Invasive Species" that pose a threat to biodiversity, agriculture, and human interests.
Common mynas can be recognized by their brown body, black hooded head, and the bare yellow patch behind the eye. Their 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 male and female look similar and are usually seen in pairs.
Common mynas are native to Asia with their home range spanning from Iran, Pakistan, India, Nepal, Bhutan, Bangladesh, and Sri Lanka; as well as Afghanistan, Uzbekistan, Tajikistan, Turkmenistan, Myanmar, to Malaysia, Singapore, peninsular Thailand, Indo-China, Japan (both mainland Japan and the Ryukyu Islands) and China. These birds are typically found in a wide range of habitats with access to water; they inhabit open woodland, mangroves, grasslands, farmlands, orchards, and urban areas.
Common mynas are social birds that roost communally throughout the year, either in pure or mixed flocks with jungle mynas, rosy starlings, house crows, jungle crows, cattle egrets, and other birds. These roosts can contain less than one hundred and up to thousands of birds. Birds start to gather in roosts before sunset and depart before sunrise. Mynas often perform communal displays (pre-roosting and post-roosting) which consist of aerial maneuvers and are exhibited in the pre-breeding season (November to March). It is assumed that this behavior is related to pair formation. During the day, Common mynas spend most of their time foraging and may travel up to 10 km between their roosting and feeding sites each day. They feed on the ground walking with occasional hops among grass looking for insects, especially grasshoppers. When mynas need to communicate with each other, they use croaks, squawks, chirps, clicks, whistles, and 'growls'; they also often fluff their feathers and bob their head in singing. They also screech warnings to their mate or other birds in cases of predators in proximity or when they are about to take off flying. Before sleeping in communal roosts, mynas vocalize in unison, which is known as "communal noise".
Common mynas are monogamous and 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. Nesting material used in nest construction includes twigs, roots, tow, and rubbish. During the breeding, season mynas become highly territorial, and neighboring pairs often fight furiously. The normal clutch size is 4-6 eggs which are incubated by the female within 17-18 days. The chicks are altricial; they are born helpless, with reddish bodies, and blind. The young usually fledge at 22 to 24 days of age and become independent 3 weeks later.
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