Modelagem de nicho ecológico de bothrops atrox e bothrops marajoensis

Abstract

The evolution of climatic niches happens more slowly than speciation processes, meaning that closely related species may end up sharing the same ecological parameters. Therefore, complexes of closely related species can generate several doubts about specificity given to their ecological convergences. To better understand the effects of these ecological parameters on closely related species, we characterized the ecological niche of Bothrops atrox and Bothrops marajoensis, two Amazonian snakes belonging to the atrox Complex, in which the species in question differ in a small number of morphological characteristics but occur in sympatry in some locations. Currently, Bothrops marajoensis is endemic to the eastern portion of the Amazon Plain, while Bothrops atrox is distributed throughout the Amazon Plain, Pantanal Plain and Guiana Plateau. Through ecological niche modeling, we investigated the areas of greatest environmental suitability for both species. Our research showed that B. atrox and B. marajoensis share a similar ecological niche, but with different occupancy densities, in addition to responding in very different ways to different variations in temperature and precipitation. We conclude that, despite similar ecological niches, species responses to temperature and precipitation expose different features of suitability between them. We also concluded that the effect of species distribution can affect their responses, since species with more restricted distributions, such as B. marajoensis, undergo to different selective pressures, when compared to species with wider distributions, such as B. atrox.