The Herpetological Journal

pp. 63-66
Authors: Bertoluci, Jaime; da Rocha, Pedro Luís Bernardo & Rodrigues, Miguel Trefaut

Abstract: Field evidence of coupled cycles of arthropod predatortadpole prey abundance in six aquatic systems of an Atlantic Rainforest site in Brazil Jaime Bertoluci, Pedro Luís Bernardo da We evaluated the patterns of abundance association between tadpoles and their aquatic arthropod predators in natural communities of Atlantic Forest in south-eastern Brazil. We distributed 10 traps in each one of six aquatic systems and counted the numbers of tadpoles and of predators captured monthly for 13 months. For each system, we quantified the temporal association between tadpoles and predator abundances and measured its strength (using Spearmańs rho coefficient) for timelags ranging from -6 to +6 months, followed by testing the hypothesis that the strength of the association differs among time-lag values. The associations were always stronger in streams than in ponds, and strongest (r ²>0.42) and always significant (p<0.016) when time-lag was zero months, resulting in significant differences of mean values of r ² across time-lags (p<0.001). A time-lag shorter than one month agrees with predictions from the model of predator-prey coupled cycles. The results also suggest that the importance of secondary factors driving abundance values in streams is stronger than in ponds, where conditions tend to be more unstable. To our knowledge, this is the first evidence of coupled cycles of predator-prey abundance with delayed dependence demonstrated with tadpoles and insects in aquatic forest systems.

Keywords: AQUATIC INVERTEBRATES, TADPOLES, PREDATOR-PREY RELATIONSHIPS, ANURAN LARVAE