THE MIGRATION PATTERNS OF QUELEA QUELEA IN AFRICA

SUMMARY Red‐billed Queleas migrate, at the beginning of the wet season, away from their dry‐season concentration areas and towards areas where rain started several weeks earlier. Considerable fat deposits are accumulated for this “early‐rains migration”. The direction taken by the migrants, the distance they must fly, and the timing of the movement are dependent upon the timing of the rains and the way the rain‐front moves. On the return “breeding migration” individuals in breeding condition stop to breed (in large aggregations) wherever they find conditions suitable for the founding of colonies. The location of the colonies can vary greatly from year to year. The migrations performed by several populations, in different parts of Africa, are predicted on the basis of general rainfall patterns, and the predictions tested against the facts available. There is evidence that individual females are able to produce a succession of broods in the same breeding season, at colonies which may be very far apart, and probably with different mates. The adaptive value of this “itinerant breeding” is discussed. Many other bird species, which breed at a particular phase of the wet‐season/dry‐season cycle, are expected to perform similar “itinerant breeding”.