Spatial distribution of an assemblage of an endemic genus of birds: an example from Madagascar

Abstract

Knowledge of the distribution and of the realised niche of a species is essential for an understanding of its ecology, especially in the case of poorly known species. To reach this goal, species distribution models (SDMs) can be developed to explain how environmental variables shape the distribution of species. The main aim of this research is to provide new insights concerning the nine species of Coua, endemic birds of Madagascar. This study is relevant because ecological studies on Couas are uncommon, and although these species are listed as Least Concern by IUCN, some of them are declining. The relationships between each species and the environment, particularly land cover, topography and climate, were investigated through MaxEnt. Next, the amount of niche overlap among species was calculated to investigate whether there is any spatial niche segregation. The results showed that the nine species of Coua select many habitat types, especially broadleaved forests, although some species also used mosaics of forests and croplands. Despite the lack of evidence of a larger spatial overlap between different Coua species with different habits than between species with similar habits, for many of them, there is overlap, which can mainly be explained by ecological and behavioural differences.