Red-billed quelea parasites found in queleas include "Haemoproteus" and "Plasmodium". The red-billed quelea is caught and eaten in many parts of Africa. Around Lake Chad, three traditional methods are used to catch red-billed queleas. Trappers belonging to the Hadjerai tribe use triangular hand-held nets, which are both selective and efficient. Each team of six trappers caught about twenty thousand birds each night. An estimated five to ten million queleas are trapped near N'Djamena each year, representing a market value of approximately US$37,500–75,000. Between 13 June and 21 August 1994 alone, 1.2 million queleas were caught. Birds were taken from roosts in the
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