Physalaemus spiniger(Anura: Leiuperinae): A Frog with an Extensive Vocal Repertoire

Abstract

Frog calls are often stereotyped and only a few species are known to vary the emission of a single note or call greatly. Calls of Physalaemus spiniger were recorded in the field and analyzed in the laboratory. We recognized and describe five different notes or calls: advertisement, territorial, fighting, release, and amplexus. These notes differ in duration, number of pulses per call, and fundamental frequency (Fh1). There was a great variation in the spectral structure and frequency modulation of the advertisement call, which had up to six harmonic frequencies (H). Of these, one to three were visible and two to three were estimated. The greatest sound intensity was recorded in H3 (1.27 kHz) and H4 (1.68 kHz). The note had an average duration of 237.63 ms and 371.57 pulses/note. The advertisement note (A) may occur in conjunction with the territorial note (T), in this case by changing its physical characteristics. The frequency modulations in the notes were both ascendant and descendant and were located anywhere in the note. We identified at least 22 different ways in which the advertisement call was emitted. The function of this variation and the observed patterns are unclear; however, this species is an excellent model for investigating call parameters as only two other species of frogs are known to possess such extensive vocal repertoires.