Breeding activity patterns, reproductive modes, and habitat use by anurans (Amphibia) in a seasonal environment in the Pantanal, Brazil

Annual patterns of breeding activity, reproductive modes, and habitat use are described for a frog community in a seasonal environment, in the southern Pantanal, Mato Grosso do Sul state, Brazil. Data were collected monthly between January 1995 and December 1998. A total of 24 species were registered, distributed in the families Bufonidae (3 species), Hylidae (10 species), Leptodactylidae (9 species), and Microhylidae (2 species). Three reproductive activity patterns may be recognized among the studied species: continuous, explosive, and prolonged; 50 % of the species were explosive breeders. Seasonal pattern of reproduction was verified for three analyzed years (1995-1997), with most species breeding during the rainy season (Nov-Jan). The reproduction was aseasonal in 1998 due to unexpected rains in the dry season, leading to an unusual breeding activity. Five reproductive modes were registered, with 62.5 % of the species exhibiting the generalized aquatic mode, and 33.3 % depositing eggs embedded in foam nests. Many species used the same sites for reproduction, although temporal partitioning and some degree of calling site segregation could be observed. Financial support: FAPESP, CNPq