Influence of environmental variables on the spatiotemporal distribution of anurans during the reproductive season in south-eastern Brazil

Resumen

The Southeast region of Brazil contains a great wealth of species of anuran amphibians, which face several threats, such as environmental degradation and climate change. Therefore, it is necessary to carry out more studies on the influence of environmental variables on their space-time distribution, especially in the breeding season. The objective of the study was to identify the main climatic and habitat variables that influence the distribution of anuran amphibians in Serra do Japi, São Paulo, Brazil. Data collection in the field was carried out on a fine scale, at the study sites Montanhas do Japi (MJ) and Sítio do Sol (SS), where the environmental variables: climatic (temperature and relative humidity of the air) and terrain elevation were measured, as well as the habitat variables (types of substrate, position within the substrate, terrain slope, height of the individual to the ground, and distance to the water mirror). The variables elevation, temperature and relative humidity were analyzed using Pearson's correlation coefficient; while habitat and location variables were evaluated through a multivariate approach, using cluster analysis with the k-means technique. In MJ, four groups were obtained, with six species of frogs, where the predominant one was Brachycephalus rotenbergae. In SS, three groups were obtained, with seven species, where the predominant one was Phyllomedusa burmeisteri. Spatiotemporal distribution was obtained under a different combination of variables, where fine information was included on substrate (water or adjacent to water, soil, vegetation) and position of the observed individual (in water or soil, leaf litter, herbaceous/shrub vegetation). It was confirmed that there is an environmental climate dependence on the reproductive conditions of anurans living in Mata Atlântica conditions, although there is little variability explained based on the analyzed data. These results contribute to the generation of more specific knowledge about the requirements of frogs during their breeding season.