Russet Sparrow

In many aspects of its behaviour, the russet sparrow is similar to the house and Eurasian tree sparrows. Like them, it feeds on the ground, but spends most of its time perching on branches. Unlike those species, it prefers open, exposed branches for perching. The russet sparrow is described as shy and wary by some observers, but J. Denis Summers-Smith found it approachable in Indian hill stations. Flocking russet sparrows feed close to the ground, moving forward as birds from the rear of a flock move to the front, in what is called "roller feeding". Outside its breeding season, the russet sparrow is gregarious and forms flocks to find food, though it infrequently associates with other birds. Wintering flocks tend to keep away from human habitation. The russet sparrow is also social at night during the winter, and it forms large communal roosts in trees and bushes. In the breeding season, the female roosts in the nests and the male nests in foliage nearby. The adult russet sparrow is mostly a seed-eater, eating the seeds of herbs and weeds as well as rice, barley, and other grains. Berries, such as those of the kingore (certain Berberis spp.), are also eaten when available. Nestlings are fed mostly on insects, especially caterpillars and larval beetles obtained on trees and flying insects caught by aerial pursuit. During the breeding season adults also consume insects. Mortality rates in the russet sparrow have not been studied, but it is known that many young birds die from Isospora infections, to which the bird has little resistance. Other recorded parasites of the russet sparrow include Protocalliphora blowflies, and Menacanthus chewing lice.

The russet sparrow is found in parts of eastern Asia and in the Himalayas. It is not known whether its distribution is continuous between these two areas, since the political sensitivity of the Brahmaputra River's valley near the China-India border makes the area less accessible to ornithologists. In the Himalayas the russet sparrow breeds from the far northeast of India through southeastern Tibet, Bhutan, Sikkim, Nepal, Uttarakhand, and Himachal Pradesh to Kashmir and Nuristan in Afghanistan. Here, the russet sparrow makes short movements to lower altitudes between November and April in many areas. In eastern Asia, the russet sparrow is found in Sakhalin, the Kuril Islands, a small part of mainland Russia, Japan, southern Korea, and part of northern China, where it is mostly migratory. It is distributed through southern China and Taiwan, and the mountainous parts of Burma, southern Northeast India, Laos, and Vietnam, where it is mostly resident. The russet sparrow also occurs as a winter visitor in southern Japan, the further south of China, and northern Thailand. In eastern Asia, the autumn migration occurs between August and November. The russet sparrow appears to be abundant in most habitats across most of its very large range, and in the some areas it is among the most common birds. In Southeast Asia, its range has contracted at lower elevations due to global warming, but it has also moved higher at high elevations and it remains common. Although its global population has not been quantified, it is assessed for the IUCN Red List as least concern for global extinction. Breeding takes place in mountains and uplands across most of the range. This preference for high altitudes is influenced by latitude: in the farthest south of its range it never breeds below 2,500 metres (8,200 ft) above mean sea level, but in the northernmost part of its range it often breeds by the sea. In eastern Asia, the russet sparrow prefers light woodland, but it is sometimes found in towns and agricultural areas. In Sakhalin, it breeds mostly in riparian forest. In Hokkaidō, the russet sparrow finds a greater food supply for its young in more remote forests, and has greater reproductive success. In the Himalayas, it is strongly associated with terrace cultivation, and it probably only spread to the Himalayas when these agricultural practices arrived 3000 to 4000 years ago. In towns where it occurs alongside the house or tree sparrow, it is found in gardens and less built up areas. In those hill stations in India where both the house and the russet sparrow occur, the house sparrow breeds around more-built up areas and bazaars, whereas the russet sparrow is "rather more up market at the larger houses with gardens and open spaces". In towns where it is the only sparrow, it is not dependent on trees, breeding around houses and eating scraps in streets. In the winter, migratory birds occur in open cultivated land and riverine grasslands, but are never far from shrubs or trees.