Structure of an anuran assembly from Chaco Serrano of Argentina

Abundance as a demographic parameter is an important part of population dynamics, allowing space-time comparisons and evaluating the health status of species. This work aimed to know the temporal structure of an anuran assembly from Chaco Serrano in central-western Argentina and to identify the influence of climatic factors on those parameters. 14 samplings were carried out from October 2012 to February 2015. Samplings were grouped into dry and rainy seasons. The abundance of each species was analyzed by: 1) mean abundances, with factorial analysis of variance and 2) proportions, as frequencies of occurrence, from Chi-square tests. Redundancy analysis was performed to relate abundance, sea -sons, and environmental variables. In both seasons Rhinella arenarum arenarum was the most abun-dant species, followed by Pleurodema tucumanum and Leptodactylus luctator. Significant differences were found in species abundance, between seasons, and between sexes, with significant interactions between these factors. In the dry season, R. arenarum arenarum and L. luctator showed differences in sex ratios, whereas in the rainy season only P. tucumanum exhibited different frequencies between males and females. The minimum temperature and the rainfall proved to be significant variables in P. tucumanum abundance. No climatic influences were found for the other species. The results of this research contribute to understanding the Chaco anuran assemblage structure, suggesting that popu-lations fluctuate over time and it may depend, in some species, on abiotic factors such as temperature and rainfall.