Influence of Seasonal Climate Variations and Food Availability on the Dynamics and Abundance of Populations of Three Granivorous and Frugivorous Bird Species (Foudia Madagascariensis, Lonchura Nana, and Coracopsis vasa) in the Dry Forest of Ankarafantsika National Park, Madagascar.

We studied the populations of three granivorous and frugivorous bird species during the dry and wet seasons over a three-year period in the dry forest of western Madagascar, particularly in the Ankarafantsika National Park region: Foudia madagascariensis and Lonchura nana (primarily granivorous), as well as Coracopsis vasa (frugivorous–granivorous). Population sizes showed significant interannual fluctuations, closely linked to variations in rainfall and the availability of food resources (seeds and fruits). A general increasing trend in population numbers was observed during years characterized by higher precipitation, which promoted increased plant productivity and improved food availability. Our results suggest that local movements of these species are not solely triggered by the complete depletion of food resources. The intensity of the dry season, as well as annual variations in climatic conditions, also appear to strongly influence mortality, spatial distribution, and seasonal movements of these species characteristic of Madagascar’s dry forests..