Sixteen species of waxbills were studied under captive conditions and their general behaviour, voice, and displays were noted. All these species had been included by Delacour (1943) in his genus Estrilda on the grounds that their morphological characters did not justify separation. The species concerned were:rubricata, rara, senegala, rufopicta, larvata, caerulescens, erythronotos, astrild, rhodopyga, troglodytes, melpoda, melanotis, temporalis, angolensis, granatina, and amandava.
In this study the ethological characters concerned are described separately for each species. A comparison of these characters reveals the existence, within these species, of distinct natural groups with common behavioural characters. These groups are also found to share common morphological characters. It is considered that the difference between these groups warrants generic separation. The relationship to these groups of the other species in Delacour's Estrilda is discussed. On the basis of a combination of behavioural and morphological characters a taxonomic revision of Delacour's genus Estrilda is presented.
The following genera are recognised:Lagonosticta; Estrilda, including E. caerulescens and E. melanotis; Aegintha, including A. temporalis; Uraeginthus with two subgenera Granatina and Uraeginthus; Nesocharis; Amandava; and Ortygospiza.