Viperid snakes are widely distributed in the South America and the greater distribution range of the family is found at the Crotalinae subfamily. Despite the abundance of this snakes along their geographic distribution, some ecological aspects remain unknown, principally at subtropical areas. In the present study, we evaluated the activity (daily and seasonal) and the use of the habitat by Bothrops diporus, B. jararaca and B. jararacussu, in an Atlantic Forest area at southern Brazil. We observed higher incidence of viperid snakes during the months with higher temperatures, while no snakes were found during the months with lower temperatures. The data suggest the minimum temperature as environmental variable with the greatest influence on the seasonal activity of this species. Considering the daily activity, we observed a tendency of snakes to avoid the warmest hours. Bothrops jararacussu tend to avoid open areas, being registered only inside and at the edges of the forest. We compared our results with previous studies realized at tropical areas and we suggest the observed seasonal activity as an evolutive response, despite the influence of the different environmental variables, according to the occurence region.

None

Crossodactylus schmidti Gallardo, 1961 is a diurnal frog inhabiting rocky streams in forested areas, recently considered as a threatened species in the Brazilian states of Rio Grande do Sul and Santa Catarina. Herein we present four new population records of C. schmidti for the northwestern region of Rio Grande do Sul state and discuss the major impacts that may be threatening the species in the state. Additionally, we present an updated map of the current known species distribution and compare morphometric data among populations from Rio Grande do Sul state and Paraná state, in Brazil, and from the province of Misiones, Argentina, based on the examination of voucher specimens available from herpetological collections.

No abstract

No abstract