Anuran tadpoles learn to recognize injury cues from members of the same prey guild

Abstract

Recognition of predation risk from cuesreleased from injured heterospecific could be beneficialwhen prey belongs to the same prey guild. Here, we performedthree experiments. Experiment 1 showed that P.thaul tadpoles reduced their activity levels when exposedto conspecific injury cues, but not when exposed toamphipod injury cues. Experiment 2 tested whether P.thaul tadpoles can learn to recognize predation risk fromchemical cues released from injured heterospecifics fromthe same prey guild (amphipod, Hyalella patagonica). Agroup of tadpoles were conditioned by exposing them to aspecific concentration of amphipod injury cues paired withconspecific injury cues. Two days later, we evaluatedchanges in the activity of tadpoles when they were exposedto amphipod cues. As a control of learning, we used anunpaired group. Additionally, we used more control groupsto fully investigate the learning mechanism. Our resultsshowed that tadpoles can learn to recognize predation riskfrom injured amphipods and that the mechanism underlyingthe observed learned response could be associative.Experiment 3 replicated Experiment 2 and also showed thata low concentration of amphipod cues did not sustain thatlearning.