Population Size, Distribution and Biomass Density of the Lesser Flamingo in the Eastern Rift Valley, 1974-76

(1) Four aerial photographic censuses of lesser flamingoes on lakes in the Eastern Rift Valley of Kenya and northern Tanzania were made during 1974-76. (2) The distribution pattern was more dispersed than had been recorded during earlier surveys in 1969 and from 1972 to March 1974. (3) About 0-5 million birds were recorded in the study range with no significant differences (P < 0.05) between the four censuses. This is significantly less (P < 0.05) than earlier comparable estimates of 1.0-15 million. It is suggested that the decline was due to emigration from the Eastern Rift Valley, particularly to southern Africa, and to mortality. (4) The 'standing' biomass density was generally in the range 10-30 g/m2.