strips are used for each nest. This species may nest several times per year when conditions are favourable. In the breeding season, males are diversely coloured. These differences in plumage do not signal condition, probably serving instead for the recognition of individual birds. However, the intensity of the red on the bills is regarded an indicator of the animal's quality and social dominance. Red-billed quelea males mate with one female only within one breeding cycle. There are usually three eggs in each clutch (though the full range is one to five) of approximately long and in diameter. The eggs are light bluish or greenish 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 with protein-rich insects. Later the nestlings mainly get seeds. The young birds fledge after about two weeks in the nest. They are sexually mature in one year. Feeding Flocks of red-billed queleas usually feed on the ground, with birds in the rear constantly leap-frogging those in the front to exploit the next strip of fallen seeds. This behaviour creates the impression of a rolling cloud, and enables efficient exploitation of the available food. The birds also take seeds from the grass ears directly. They prefer grains of in size. Red-billed queleas feed mainly on grass seeds, which includes a large number of annual species from the genera Echinochloa, Panicum, Setaria, Sorghum, Tetrapogon and Urochloa. One survey at Lake Chad showed that two-thirds of the seeds eaten belonged to only three species: African wild rice (Oryza barthii), Sorghum purpureosericeum and jungle rice (Echinochloa colona). When the supply of these seeds runs out, seeds of cereals such as barley (Hordeum disticum), teff (Eragrostis tef), sorghum (Sorghum bicolor), manna (Setaria italica), millet (Panicum miliaceum), rice (Oryza sativa), wheat (Triticum), oats (Avena aestiva), as well as buckwheat (Phagopyrum esculentum) and sunflower (Helianthus annuus) are eaten on a large scale. Red-billed