Red-billed quelea sound due to the many wing beats. After arriving at the roost or nest site, birds keep moving around and make a lot of noise for about half an hour before settling in. Both males and females call. The male sings in short bursts, starting with some chatter, followed by a warbling "tweedle-toodle-tweedle". The red-billed quelea is mostly found in tropical and subtropical areas with a seasonal semi-arid climate, resulting in dry thornbush grassland, including the Sahel, and its distribution covers most of sub-Saharan Africa. It avoids forests, however, including miombo woodlands and rain forests such as those in central
Cardinal quelea on its head. Gustav Hartlaub was the first to described the cardinal quelea, giving it the scientific name "Hyphantica cardinalis" in 1880, based on specimens that were collected by Emin Pasha near Lado in South-Sudan during 1879. In 1951, Hans von Boetticher regarded the cardinal quelea and red-headed quelea sufficiently different from the red-billed quelea to create a new genus "Queleopsis". Its name in Swahili is "kwelea kidari-chekundu". Molecular phylogeny indicates that ancestors of the quelea species might have originated in India and dispersed to Africa. Based on more recent DNA-analysis, the red-headed quelea forms a clade with the cardinal