Detalle de: First insights into the overwintering biology of Alsodes gargola frogs and tadpoles inhabiting harsh Andean-Patagonian alpine environments

The alpine environment occurs in mountains above the treeline and is regarded as one of the harshest habitats on the earth. Among vertebrates, a number of amphibian species have been particularly successful in the colonization of alpine environments throughout the world, and several studies have been focused on their overwintering biology (e.g. Bradford, 1983; Sinsch, 1989; Guyetant et al., 1994; Navas, 1996; Hou and Huang, 1999; Clemann, 2002). However, the overwintering biology of the amphibian species living in alpine Andean-Patagonian environments still remains unexplored. In temperate regions like Patagonia, the alpine environment is characterized by short growing seasons and long winters (Burgis, 1987; Korner, 2001; Sommaruga, 2001), and amphibians living in such environment may spend most of their lives overwintering. Most adult anurans display either of three responses when winter approaches: 1) submersion, 2) permanence in land in a thermally isolated shelter, and 3) permanence in land tolerating freezing (Pinder et al., 1992). In some species, individuals of the same population may respond differently to the approaching winter (e.g. Sinsch, 1991; Laitinen and Pasanen, 1998).