Ecologia de três espécies simpátricas de viperídeos (Serpentes: Viperidae) no Parque Estadual do Turvo, Rio Grande do Sul, Brasil

Abstract

At Parque Estadual do Turvo, an area of atlantic forest in the northwest of Rio Grande do Sul, Brazil, was recorded in sympatry by different sampling methods three viperids species. Bothropoides diporus the snake was more common, and also the best adapted to dry and degraded areas (64.95% of total), Bothropoides jararaca (21.65%), was sampled in degraded areas and inside forest, was the only one be sampled perched and Bothrops jararacussu (13.40%) was restricted to forested areas, particularly near water bodies. The offspring of B. jararaca and B. jararacussu inhabit the streams. Compared by a multiple linear regression the number of monthly meetings of snakes with the following variables: average monthly minimum temperature, monthly rainfall and monthly insolation during the study period. Significant difference between the number of snakes caught between the stations of the largest and lowest temperatures. There was no significant difference in the daily activity of snakes. The diet of B. diporus and B. jararaca is composed of mammals, amphibians and reptiles, and mammals the item most used by both species was not observed differences in diet between males and females of B. diporus, showed had specialized diet in mammalian, was not observed shift ontogenetic diet B. jararaca. The method provided the best results was local collectors (65.99%) followed by occasional encounters (17.53%), time constrained search (12.37%), search in roads (4.12%). Pitfall traps with drift fences were not successful in viperids in this study