Predation risk and jumping behavior in Pseudopaludicola aff. falcipes tadpoles

Abstract

Tadpoles of Pseudopaludicola aff. falcipes are capable of jumping out of small temporary puddles where they occur. In this system, odonate naiads are the main predators. Considering the hypothesis that jumping behavior represents an antipredator tactic, we addressed the following predictions: 1) tadpoles will jump more frequently from puddles with predators than from puddles without predators; 2) tadpole mortality will increase if tadpoles are prevented from jumping; 3) it would be more common to find tadpoles in puddles where predators are absent; and 4) predator and prey coexistence would be more probable in large puddles than in small ones. To test predictions 1) and 2), we conducted 2 laboratory experiments. In Experiment 1, we evaluated the jump frequency of tadpoles in 3 treatments ( tadpoles in the presence or absence of a predator, or using an inanimate object as predator presence control). In Experiment 2, we compared tadpole survival in 2 conditions: Tadpoles were allowed or not to jump. To test predictions 3) and 4), we conducted a field study to determine how predators and prey are distributed throughout the habitat. Experiments demonstrated that jumping behavior occurred more frequently when a predator was present and that tadpoles prevented from jumping were more susceptible to predation. The field study indicated that tadpoles and odonate naiads were distributed in a negatively associated, but puddle-size dependent pattern. Our results are congruent with the predictions, therefore, confirming the jumping behavior as an effective antipredator tactic.