Acridotheres tristis
common myna

Common mynas are native to south Asia. Their natural breeding range is from Afghanistan through India and Sri Lanka to Bangladesh. They have been introduced to many tropical areas of the world except for South America. Common mynas are a resident species in India, although occasional east-west movements have been reported. ("National Geographic Field Guide to the Birds of North America and 4th ed.", 2002; Invasive Species Specialist Group, 2006; Rousset and Thorns, 2007)

Common mynas occupy a wide range of habitats in warm areas with access to water. In their native range, common mynas inhabit open agricultural areas such as farmlands as well as cities. They are often found on the outskirts of towns and also outlying homesteads in desert or forest. They tend to avoid dense vegetation. They are most common in dry woodlands and partly open forests. On the Hawaiian islands, they have been reported from elevations of sea level to 3000 meters. Common mynas prefer to roost in isolated stands of tall trees with dense canopies. (Australian Museum, 2003; Invasive Species Specialist Group, 2006; Kannan and James, 2001)

Common mynas range in body length from 23 to 26 cm, weigh anywhere from 82 to 143 grams, and have a wingspan of 120 to 142 mm. The female and the male are monomorphic for the most part – the male is only slightly larger, with a greater body mass and wingspan. Common mynas have yellow bills, legs, and eye skin. They are dark brown with a black head. They have white undertail coverts, tail tips, patches at the base of their primaries, and wing linings that are distinctive in flight. Juveniles have more brownish heads than adults. Common mynas are often confused with noisy miners (Manorina melanocephala). In contrast to common mynas, noisy miners are slightly larger and mostly grey. ("National Geographic Field Guide to the Birds of North America and 4th ed.", 2002; Australian Museum, 2003; Invasive Species Specialist Group, 2006)

Little is known about the lifespan of common mynas. Reports suggest an average life expectancy for both sexes of 4 years. Lack of food or resources is the biggest limiting factor in the survival of common mynas. Other factors that contribute to mortality rates are poor selection of nest sites and unfavorable weather. (Kannan and James, 2001)

Common mynas are social, with juveniles forming small flocks after they leave their parents. Adults forage in loose flocks of 5 or 6, composed of single birds, pairs, and family groups. Outside of the breeding season they roost in large groups that can vary from tens to thousands. Communal roosting is helpful for defense against predators and also for food distribution. During the breeding season, common mynas can be aggressive and violent while competing with other pairs over nesting sites. Common mynas are described as tame, gregarious, and bold, and engage in allopreening within mated pairs. When foraging, these mynas hop sideways and saunter along the ground and on branches. Common mynas have also been observed participating in anting with fire ants. (Kannan and James, 2001; Net Industries, 2007)

Home Range

The home range of common mynas consists of several regularly used day sites rather than a single contiguous area. Total home ranges average around 0.25 km2. The territory around nests is strongly defended, although sometimes nests are found in large colonies. Average territory size in India is 117.04 m2. (Kannan and James, 2001; Net Industries, 2007)

Common mynas communicate vocally with other mynas and other bird species. They have a wide variety of alarm calls, that can warn other bird species as well. During the day, pairs resting in the shade also utter songs while half-bowing and bristling their feathers. When under duress, common mynas utter high-pitched screams. Parents sometimes utter a specific trill when approaching their nest with food, which signals the nestlings to begin begging. In captivity, common mynas are able to imitate human speech. Both females and males sing, but males sing more frequently. Common mynas also participate in loud dawn and dusk choruses. (Kannan and James, 2001)

Common mynas are omnivorous and feed on almost anything. Their primary diet consists of fruit, grain, grubs, and insects. They prey on eggs and young of other birds, such as akepas (Loxops coccineus). They sometimes even wade in shallow waters to catch fish. Common mynas feed mostly on the ground. In residential areas they eat anything from garbage to kitchen scraps. Common mynas eat small mammals, such as mice, as well as lizards and small snakes. They also eat spiders, earthworms, and crabs. Common mynas eat mostly grains and fruit, but also feed on flower nectar and petals. (Australian Museum, 2003; Invasive Species Specialist Group, 2006; Kannan and James, 2001)

Common nest predators of common mynas are house crows (Corvus splendens) and house cats (Felis silvestris). Javan mongooses (Herpestes javanicus) raid nests to take nestlings and eggs. Humans (Homo sapiens) in some of the Pacific Islands also eat common mynas. Common mynas roost together for predator defense and often mob predators in flocks. They warn each other through alarm calls. (Kannan and James, 2001)

Common mynas are important pollination or seed-dispersal agents for many plants and trees. On the Hawaiian Islands they disperse the seeds of Lantana camara. They also help control cutworms (Spodoptera mauritia) on the Hawaiian Islands. Common mynas also act as hosts for various parasites such as nematodes, tapeworms, trematode flukes, arthropods, and bird mites. In areas where they have been introduced they negatively impact native bird and seabird species by preying on eggs and nestlings. (Kannan and James, 2001)

Common mynas are able to establish themselves in almost any habitat and, as a result, have become an invasive species in some areas outside of their native range. They are considered a pest because they eat grain or fruit from agricultural crops, such as fig trees. They are also seen as a nuisance for their noise and droppings in the vicinity of human habitation. (Invasive Species Specialist Group, 2006; Net Industries, 2007)

Common mynas may be helpful in reducing insect populations in agricultural areas. On the Hawaiian Islands, they help control populations of cutworms (Spodoptera mauritia). Common mynas also pollinate and disperse the seeds of economically important trees. Common mynas are often sold as pets for their intelligence and ability to mimic human speech. In 1883, common mynas were introduced into the cane fields of Australia to combat insect pests such as plague locusts and cane beetles. (Australian Museum, 2003; Kannan and James, 2001)

Common mynas remain common throughout much of their range.