Efeitos antrópicos sobre a distribuição e abundância de crocodilianos em córregos urbanos no município de Palmas – TO

Abstract

Deforestation, burning, illegal hunting, pollution, urban growth and inadequate disposal of solid waste constitute constant anthropogenic pressures on water bodies in urban areas, with implications for local the aquatic biodiversity, such as alligators. As they are animals at the top of the trophic chain, negative effects on their populations can cause an ecosystem imbalance due to their biological control functions, abundance of fish and non-proliferation of diseases. In the present study, the relationship between human presence and its anthropic actions on the use of crocodilian space was evaluated, expanding the knowledge related to the population ecology of these reptiles in urban areas, from the population survey of the species, characterization of the environment, identification and selection of microhabitats by the animals, complementing with water quality analyses of the Brejo Comprido and Sussuapara streams, located in the municipality of Palmas, Tocantins, Brazil. The results showed a more anthropized classification for Brejo Comprido in relation to Sussuapara, with the factors "use by humans" and "presence of solid waste" as worse environmental problems, in the same way, it was more densely populated in relation to the other. The microhabitats with the highest percentage in the study areas in the rainfall seasonality were: anthropic structure, flooded, gravel and land, while for dry season they were: anthropic structure, antlers and gravel. The microhabitats that had the most occurrences of animals were: antlers, puddles, grassy vegetation and anthropic structure, with the highest rate of encounters in the dry season. The animals did not show a preference for the microhabitats, except in 2 points (point 3 and Cesamar) of Brejo Comprido, one in the rain season and the other in the dry season, respectively. Water quality was classified as good for both by the Water Quality Index (WQI).