Diverse types of advertisement calls in the frogs Eupsophus calcaratus and E. roseus (Leptodactylidae): a quantitative comparison

The variability of the advertisement calls of males from two Chilean populations of the leptodactylid frogs, Eupsophus calcaratus and E. roseus was studied and their calling behaviour further defined. Characteristic audio spectrograms and oscillograms for each species are presented. The spectral and temporal features of the calls were analysed, and intra-population and inter-specific differences in sound parameters were tested using correlation and discriminant function analysis. The calls of both species were tonal, had specific frequency modulation patterns (FM), and showed substantial inter-individual variation in several of their components. At least four discernible types of FM patterns were found in both species. Audio-spectrogram correlation and discriminant analysis showed that the quantitative characteristics of the calls of the species were clearly distinct; the most discriminating parameters were frequency, inter-call interval, and fundamental frequency.