The composition of birds in the Chengue Bay mangrove was surveyed between August and October 2001. A total of 50 species of birds was found, and an increase in abundance of migratory species was noted in October, establishing the importance of mangrove as a wintering area or as a roosting area during southward migration. The bird density was greater in the lagoons than in the saltpetre , owing to the environmental heterogeneity in a limited space in the lagoons, and to the shape and structure of the mangrove canopy