The influence of internote-interval variation of the advertisement call on the phonotactic behaviour in male Allobates femoralis (Dendrobatidae)

Abstract

Acoustic conspecific recognition depends on spectral and temporal call properties, but not all of these are necessary for species identification. To test the importance of the advertisement call's internote interval of the dendrobatid frog Allobates (=Epipedobates) femoralis, we conducted field playback experiments with modified conspecific calls and investigated phonotactic responses. Allobates femoralis males showed positive phonotaxis when calls with internote intervals varying up to ±60% of the population's mean were presented. No phonotactic approach was observed in response to modified advertisement calls containing internote intervals of the syntopic heterospecific leptodactylid frog Adenomera hylaedactyla. However, 26.7% of the A. femoralis males tested showed positive phototoxic when altered advertisement calls with internote intervals of the syntopic heterospecific dendrobatid frog Epipedobates cf. hahneli were presented. Our results show that only a combination of different acoustic call parameters provides correct species-specific recognition. © 2007 Brill Academic Publishers.