The chestnut sparrow (Passer eminibey) is a species of passerine bird in the sparrow family Passeridae. It is the smallest member of the sparrow family, at about 11 cm  long. The breeding male has deep chestnut plumage and the female and juvenile are coloured a duller grey with some chestnut markings. Like its closest relatives in the genus Passer, the Arabian golden sparrow and the Sudan golden sparrow, it is gregarious and found in arid areas. Ranging through the east of Africa from Darfur in Sudan to Tanzania, it is found in dry savanna, papyrus swamps, and near human habitation. Adults and juveniles both feed mostly on grass seeds, and fly in flocks, often with other species of birds, to find food. It nests in trees, building its own domed nests, and also usurping the more elaborate nests of weavers.

Source : Wikipedia