Red-billed quelea in colour, sometimes with some dark spots. Some clutches contain six eggs, but large clutches may be the result of other females dumping an egg in a stranger's nest. Both sexes share the incubation of the eggs during the day, but the female alone does so during the cool night, and feeds during the day when air temperatures are high enough to sustain the development of the embryo. The breeding cycle of the red-billed quelea is one of the shortest known in any bird. Incubation takes nine or ten days. After the chicks hatch, they are fed for some days
Red-headed quelea on recent DNA-analysis, the red-headed quelea forms a clade with the cardinal quelea ("Q. cardinalis"), and this clade is sister to the red-billed quelea "Q. quelea". The genus "Quelea" belongs to the group of true weavers (subfamily Ploceinae), and is most related to "Foudia", a genus of six or seven species that occur on the islands of the western Indian ocean. This clade is sister to the Asian species of the genus "Ploceus". The following tree represents current insight of the relationships between the species of "Quelea", and their closest relatives. Red-headed quelea The red-headed quelea ("Quelea erythrops") is a