RESUMO
Mating calls of three frog species abundant in northeast India Rana tigerina, Rana cyanophlyctis and Rana limnocharis were recorded in the fields of Assam and Meghalaya during their breeding season (July-August, 1991). The calls were analysed for their temporal and spectral characters. They were species specific, with distinct call duration and call period, number of pulses per call and interpulse interval, and dominant frequency and frequency domain. A comparison of the mating calls of Rana cyanophlyctis with those of the sibling Rana ehrenbergi from Yemen showed differences in their temporal and spectral characters, supporting the suggestion that these two species are distinct species, rather than subspecies of the same species. Differences in the temporal and spectral pattern were found in the mating calls of morphologically alike specimens of Rana limnocharis, indicating that the present morphotype Rana limnocharis in northeast India is composed of several species.