The village indigobird or steelblue widowfinch (Vidua chalybeata) is a small songbird belonging to the family Viduidae. It is distinguishable from other indigobird species by bill and leg colours, the colour tinge of the male's breeding plumage, song, and to lesser extent, the nestling's plumage and mouth pattern. The bill colour can be red or white depending on the population, and there is some regional variation in the colour tone of the male's plumage. It is a resident breeding bird in most of Africa south of the Sahara Desert. This indigobird is found in many open habitats including open woodland, scrub and cultivation, but, as its name implies, it is most readily seen near villages.
It is a brood parasite which lays its eggs in the nests of red-billed firefinches. Unlike the common cuckoo, it does not destroy the host's egg. Typically, 2-4 eggs are added to those already present. The eggs of both the host and the firefinch are white, although the indigobird's are slightly larger. The nestling indigobirds mimic the unique gape pattern of the fledglings of the host species.
Source : wikipedia