Red-billed quelea far above the bill, and the underparts may have a pink wash. There is much variability within subspecies, and some birds cannot be ascribed to a subspecies based on outward appearance alone. Because of interbreeding, specimens intermediate between subspecies may occur where the ranges of the subspecies overlap, such as at Lake Chad. The female pin-tailed whydah could be mistaken for the red-billed quelea in non-breeding plumage, since both are sparrow-like birds with conical red-coloured bills, but the whydah has a whitish brow between a black stripe through the eye and a black stripe above. Flying flocks make a distinct
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