Blue Waxbills inhabit savannas, woodlands and gardens with easily accessible water sources. They feed mostly on grass-seeds, and to a lesser extent insects like termites. They are normally seen in pairs or small groups, though larger flocks do occur. At night they prefer roosting in the top of a tall thorn tree. They will also often mix with other kinds of small seed-eaters.
These small birds (8-13g) breed almost throughout the year, with a peak in summer after good rains. Both sexes construct the oval-shaped grass-nest, normally in a thorny tree and near wasp nests. Sometimes they’ll take over disused nests built by other species and adapt it to their requirements. Both parents incubate the clutch of 2-7 eggs, which hatch in less than 2 weeks, and feed the chicks on seeds and insects until they fledge and become independent within 3 – 5 weeks.
The Blue Waxbill occurs commonly from South Africa to Angola in the northwest and Tanzania in the northeast, and is listed as being of least concern by the IUCN. In South Africa it is found from Kwazulu-Natal and the Free State nothwards and is one of the most populous species in these parts, probably numbering in the hundreds of thousands at least. The species is exploited for the pet trade to a limited extent.