Reproductive patterns of two sympatric rhacophorid frogs, Buergeria japonica and B-robusta, with comments on anuran breeding seasons in Taiwan

Present study tested a hypothesis that the seasonal reproductive pattern wo uld be similar between two sympatric congeneric species of frogs, Buergeria japonica and a. robusta, by examining, fat body, liver and gonadal cycle. In total, 132 and 148 adult frogs, respectively, were collected from Taichu ng, Central Taiwan during July 1996 and July 1997. Both species were classi fied as prolonged breeders, breeding from March to August. This breeding se ason differs from those in conspecific populations from other localities. I n both species, adult females attained larger snout-vent length (SVL), body mass (BM), head length (HL), and head width (HW) than males. The smaller s ize of male in these species is inconsistent with a previous energetic cons traint hypothesis that smaller males are caused by the costs of advertising , maintaining territories, and lower food intake in prolonged breeding spec ies. Neither B, japonica nor a. robusta showed a significant positive corre lation between female ovary mass and female SVL, indicating that fecundity selection does not directly affect female body size. Also, timing of reprod uction in three other anurans from the present study site is also discussed .