Pulse variations of the advertisement calls of slender toads, genus Ansonia (Amphibia: Anura: Bufonidae) species complex in the Philippines

Abstract

The study was undertaken with the notion that pulse, as the smallest undividable unit of calling frogs/toads and a static variable, is a relevant parameter for species recognition, particularly pulse rates and number of pulses per call. Thus, would help shed light in the reassessment of the identity of the Ansonia species complex. The pulse characteristics of the advertisement calls of Ansonia species recorded from the eight rivers in Mindanao, Philippines were described and differentiated in relation to their call features, body sizes, and the ecological attributes of the rivers. The number of pulses per call, pulse rate, pulse duration, and interval were taken into account and analyzed for bioacoustics using Raven Pro 1.4 for Windows (2011). Five one-minute-call slices served as replicates per individual toad recording using a Tascam DR-1 Portable Solid State Recorder and a uni-directional external microphone. Results revealed variations in these pulse characteristics. These pulse features showed highly significant variations except for pulse interval. In general, Ansonia sp.1 of Maragang River stood as one cluster from the rest of the toads. These features also exhibited high correlations with other call parameters, peak call frequency, body sizes, and ecological features.