About Lonchura punctulata (Linnaeus, 1758)
The scaly-breasted munia (Lonchura punctulata) is about 11–12 centimetres (4.3–4.7 in) long and weighs 12–16 grams (0.026–0.035 lb). Adult individuals have a stubby dark bill typical of grain-eating birds, brown upperparts, a dark brown head, and white underparts marked with dark scale patterns. The sexes have similar appearance, though males have darker underside markings and a darker throat than females. Immature scaly-breasted munias have pale brown upperparts, do not have the dark head that adults possess, and have uniform buff underparts. This immature plumage can be confused with the juveniles of other munia species, including the tricoloured munia (Lonchura malacca) across Asian and island populations, and the black-throated munia (Lonchura kelaarti) found in parts of India and Sri Lanka. Scaly-breasted munias occupy a range of habitats, but they usually stay close to water and grassland. In India, the species is especially common in paddy fields, and it is considered a minor pest because it feeds on cultivated grain. They are found mainly on lowland plains, but can also be seen in the foothills of the Himalayas at altitudes near 2,500 m (1.6 mi), and in the Nilgiris they occur at altitudes up to 2,100 m (6,900 ft) during the summer. In Pakistan, the species is restricted to a narrow region stretching from Swat in the west to Lahore, and it avoids desert zones. It occurs again in India east of the area between Ludhiana and Mount Abu, and it has also been rarely observed in Kashmir. Outside of its native range, escaped captive scaly-breasted munias frequently establish wild populations in areas with suitable climates, then go on to colonise nearby new areas. Established wild populations of escaped cagebirds have been recorded in the West Indies (Puerto Rico since 1971), Hawaii (since 1883), Japan, and the southern United States, mainly in Florida and California. On Oahu, Hawaii, scaly-breasted munias compete for habitat with the tricoloured munia, and they tend to be rare in areas where this competitor is present. The species has been introduced to many other parts of the world because it is popular as a cage bird, and wild populations have become established in these introduced regions. The scaly-breasted munia feeds mainly on grass seeds, small berries including Lantana berries, and insects. While its bill is adapted for crushing small grains, it does not use the lateral lower mandible movements that help species like greenfinches dehusk seeds. Like some other munia species, scaly-breasted munias may also feed on protein-rich algae before their breeding season. Because these birds are easy to keep healthy in captivity, they have become popular subjects for studies of animal behaviour and physiology. Optimal foraging theory, which states that animals minimize the time and energy they spend to maximize their food intake, has been tested by researching the feeding strategies scaly-breasted munias use to increase feeding efficacy.
