On the composition and temporal dynamics of a snake community at the Cerrado-Amazonia ecotone.

Understanding the factors shaping the temporal dynamics of ecological communities is crucial for biodiversity conservation during the Anthropocene. In this study, we describe the species composition of a snake community within the Cerrado-Amazonia transition, the largest forest-savanna transition zone in the world, and a highly threatened ecosystem in Brazil. We also analyzed community structure over time using temporal diversity indices. The community had a balanced mix of forest and savanna species, with the Dipsadidae family exhibiting the highest diversity, including two potentially new taxa. Our research, conducted through extensive fieldwork and literature records, documented 53 species across seven families. This comprehensive approach provided a detailed picture of the snake diversity in this unique transitional zone. The results corroborate previous observations that snake richness is high during wet seasons and show that the community has complex temporal dynamics tied to seasonal shifts. The snake community was active throughout all seasons, with species turnover higher during the wet and dry seasons, marked by a high appearance rate during wetter periods and a high disappearance rate of species during the dry season. The community exhibited positive covariance among species, with each species fluctuating independently over time. However, ongoing deforestation in the region may impact species abundance. These characteristics may be attributed to the unique ecological pressures and adaptations of the transition zone. The presence of species with diverse distribution patterns and habitat preferences underscores the environmental and biogeographic complexity of the region, indicating that the Cerrado-Amazonia transition serves as a critical habitat for a wide range of snake species. We also identified two potential new species, emphasizing the urgent need for further research on the effects of environmental changes on local snake populations and biodiversity. Our findings contribute to understanding Neotropical patterns of herpetofauna diversity and underscore the importance of protecting transitional ecosystems. As these areas face increasing threats from human activities, understanding their ecological dynamics becomes essential for developing effective conservation strategies. Our study serves as a call to action for preserving the unique biodiversity of the Cerrado-Amazonia transition zone and mitigating the adverse impacts of anthropogenic changes.