Red-billed quelea collected from under large roosts in Nigeria and used as a fertiliser. Tourists like to watch the large flocks of queleas, such as during visits of the Kruger National Park. The birds themselves eat pest insects such as migratory locusts, and the moth species "Helicoverpa armigera" and "Spodoptera exempta". The animal's large distribution and population resulted in a conservation status listed as least concern on the IUCN Red List. The red-billed quelea is sometimes kept and bred in captivity by hobbyists. It thrives if kept in large and high cages, with space to fly to minimise the risk of obesity.
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