The nocturnal movements of breeding Greater Flamingos (Phoenicopterus ruber roseus) between Fu- ente de Piedra Lake (Fuente de Piedra, southern Spain) and foraging areas was studied from 1986 to 1988. Fuente de Piedra is the only seasonal lake in Europe where Greater Flamingos breed regularly. Analysis of color-banded birds and fluctuation in flamingo numbers established that the marshes of the River Guadalquivir and its surround- ing wetlands, situated within a 200-km radius from Fuente de Piedra, play an important complementary role to Fu- ente de Piedra during the breeding cycle when chicks are in creche. During the incubation period and the presence of chicks in the creche, flamingos may fly to foraging areas. During chick-brooding, however, movements were more restricted as evidenced by more attendance to chicks. Two flight directions were used from Fuente de Piedra: south- west (SW) and northeast (NE). The seasonal variation of numbers of birds joining departure groups at Fuente de Piedra was related to the number of chicks in the creche and numbers of flamingos in the Guadalquivir marshes. The cross-country movements between the breeding colony at Fuente de Piedra and the foraging areas were con- ducted at night, probably because they are energetically more profitable with lower temperatures. During the night, the arrival of adults to the lake is greatest, activity within the colony is very intense, and most feeding of chicks is undertaken. When the chicks in the creche were small and found resources were abundant, some adults arriving to feed chicks in early evening then returned to the foraging sites the same night. This behavior involved movements in excess of 300 km each night. At the end of the breeding season, the nocturnal flocks returned later to Fuente de Piedra, and the majority of adults remained in the lake until the following day. During this phase of reproduction, the feeding of chicks was more spaced out and some adults stopped feeding their chicks, which then began to leave the colony. Conservation of the flamingo breeding colony site at Fuente de Piedra requires protection not only of the breeding habitat but also of the wetlands used for foraging.