Spatial and Temporal Distribution of Anurans in an Agricultural Landscape in the Atlantic Semi-Deciduous Forest of Southeastern Brazil

Abstract

Studies on anuran communities have shown several levels of reproductive segregation between species, and many studies have reported a spatial segregation in calling sites. Variation in spatial and temporal distribution of species in amphibian communities facilitates coexistence among species and decreases the possibility of hybridization between congeneric species. Here we describe the spatial and temporal distribution of anurans at RPPN Fazenda Lagoa, municipality of Monte Belo, southern Minas Gerais state, and compare species composition with other published anuran surveys from southeastern Brazil. Data were obtained from August 2003 to May 2005 with multiple survey methods. Twenty-four species from seven families were found: Brachycephalidae (2 species), Bufonidae (3), Cycloramphidae (3), Hylidae (9), Leptodactylidae (5), Leiuperidae (1) and Microhylidae (1). There was a predominance of species typical of clearings. Only six species (25%) were found exclusively in forests. Species richness was highest between October and December and lowest in July and August. Temperature explained about two thirds of the monthly variation in calling species richness while rainfall does not seem to be important in determining monthly calling species richness. The same area had already been studied in 1998. We recorded eight species which were not recorded in 1998, whereas we failed to find four species recorded in 1998; it is possible that one of the latter experienced population decline. When we compared the composition of 11 localities from southeastern Brazil, the anuran community from Fazenda Lagoa was most similar to that of Botucatu and this similarity may reflect the occurrence of species which are commonly found in manmade habitats. Geographic distance among the areas compared explained a relatively low amount (21%) of the variation in community composition; vegetation type seems to be more important than distance.