História natural de uma comunidade de serpentes da serra do sudeste do Rio Grande do Sul, Brasil

• Ano de defesa: 2005
• Autor(a) principal: Outeiral, Arlete Ballestrin
• Orientador(a): Lema, Thales de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul; Porto Alegre
• Palavras-chave em Português: ZOOLOGIA; SERPENTES - RIO GRANDE DO SUL
• Link de acesso: http://hdl.handle.net/10923/5303

In the last three decades, the study of communities has made great progress; however, there have been few studies on snakes with more than one species utilizing the same area. Campos sulinos are an important biome in the Subtropical region with temperate climate of the Neotropical region, presenting open formations, semideciduous and ciliar forests along water courses. There is a great relevance in relation to its biodiversity, but its composition and community structure is unknown. Our goal in the present study was to know the diversity, the natural history and some ecological aspects of species of the snake community at Serra do Sudeste in Rio Grande do Sul, Campos Sulinos. Snakes’ searching was undertaken from January 2000 to June 2003, through the following four methods: time constrained search (walking and by car); pitfall traps; resident collectors and study in scientific collections. The study area is characterized by the presence of semideciduous forest and field formation intermingled by ciliar forests. Species richness in the collecting area was represented by the presence of 28 species other than four which were identified in the collection of MCP (Museu de Ciências da Pontifícia Universidade Católica do Rio Grande do Sul), totaling 32 species. The principal method to estimate the actual number of species (richness) as well as the number of specimens (abundance) was the collection made by resident collectors (23/294) and pitfall traps (916/140) respectively. The richness (Jackknife 1 and 2, Chao 1 and 2) was estimated among 32 and 36 species. Snake community composition of Serra do Sudeste was more similar to other taxocenosis which utilize areas with field formation (pampas), followed by open areas with semideciduous and Atlantic forest. The two more abundant species were Bothrops pubescens (21%) (Viperidae) and Philodryas patagoniensis (18%) (Colubridae).The species richness values obtained through traps installed at the field and inside the forest were different: species richness of forest composition (n=14), diversity (H’=2,46) and equitability (E=79%) was greater than field (n=12, H’=2,13, E=51%). The most common snakes were terrestrial and diurnal in the utilization of macro and microhabitat. Most snakes were found along vicinal roads (n=60 dislocation from one place to another) and near home environments (n=58). The mensal activity of snakes was correlated with the temperature (r2=0. 52). The three more abundant species are generalist feedeers. Anuran and lizards were the most frequently prey itens of snakes, followed by mollusks, arthropods and birds. Species composition followed the characteristic pattern of colonization and dispersion in the snake lineage known for the Neotropical region, reflecting the patterns of interference suffered by historical, phylogenetic and ecological factors.