Seasonal Variation in a Male Reproductive Aggregation of the Tree Frog Scinax albicans (Anura, Hylidae) in a Mountain Stream in the Brazilian Atlantic Forest

摘要

Amphibians are regarded as highly sensitive to environmental changes. Their biological features make them vulnerable to several kinds of disturbances, including habitat modification (especially changes in the hydrology), climatic changes (especially rainfall reductions), and water pollution, including pesticides, sewage and acidic rains. Several authors have pointed out a global decrease in amphibian abundance and diversity, which can be linked to global climatic changes and/or to habitat modification, among other factors (Heyer et al. 1988; Houlahan et al. 2000; Young et al. 2001), although it may be difficult to distinguish clearly between human impacts and natural fluctuations (Pechmann et al. 1991).