Ecology ofThamnodynastes hypoconiain Subtropical–Temperate South America

The ecology of the genus Thamnodynastes has received little study, and problems with its taxonomy have generated imprecise and incorrect data. We analyzed the reproductive biology, sexual dimorphism, feeding ecology, habitat use, and seasonal activity of Thamnodynastes hypoconia in its subtropical–temperate area of distribution. We discuss its main ecological traits in light of the competition and predation, and the deep-history hypotheses. Males and females attained sexual maturity at different body sizes, with females achieving the largest sizes. In this species, the males and females had no difference in the body size, and males had more ventral scales than did the females. The females' reproductive cycle was seasonal and not annual, with parturition occurring in summer, whereas the cycle of the males was continuous. Thamnodynastes hypoconia feeds mainly on amphibians (97%) and occasionally on lizards (3%). As in other Thamnodynastes snakes, hylid frogs were the most common type of prey consu...