Como fatores ambientais afetam a abundância e distribuição de duas espécies do mesmo gênero de rãs da Amazônia

Abstract

To test the hypothesis that environmental factors would act in different ways on the abundance and distribution of phylogenetically related species, we sampled two anuran species, Phyzelaphryne miriamae and Phyzelaphryne sp., along approximately 600 km in the Brazilian Amazonia. Data sampling was carried out in 11 permanent sampling modules distributed along ~600 km in the Purús-Madeira Interfluve between 2013 and 2014. Using mixed generalized linear models, we found that the species have distinct environmental associations, which may be enabling them to coexist in sympatry. Phyzelaphryne miriamae was more frequent in environments with deep water-table, characteristics common to more open environments, while P. sp. showed no preference for any evaluated environmental variable. Due to its larger body size in respect to P. sp., P. miriamae may be more resistant to dehydration, and therefore able to occupy drier environments. Our results are in concordance with the idea that the evolution of characteristics resulting from selection must have occurred in a way that the competition for resources between closely related species was reduced, thus allowing a coexistence in sympatry.