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

Abstract

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