Mating call variation in lake frogs referred to as Rana ridibunda Pallas, 1771 - taxonomic implications

The mating call of Rana ridibunda varies considerably among populations throughout its geographical range of distribution. Multivariate analyses of nine call parameters demonstrate the existence of three distinct groups of populations which differ in the degree of temperature dependence of four parameters, and specifically in the number of pulses/pulse group and pulse groups/ call. Since discriminant functions distinguish among these groups with very low rates of false classification and since the degree of differentiation between the groups is similar to that towards R. perezi, taxonomic consequences are indicated.The lake frog populations near the Caspian Sea (CIS) inhabit the terra typica restricta and, thus, represent R. ridibunda. The lake frogs of Armenia (CIS) and of Thrace (Greece) also belong to this species. The mating call of R. ridibunda consists of 19 pulses/pulse group and of 7 pulse groups/call on the average. Finally, the southwestern form, inhabiting Greece and southern Yugoslavia, is named R. balcanica sp. n. Its mating call is characterized by 29 pulses/pulse group and 4 pulse groups/call on the average. Finally, the southeastern form ranging from Turkey to Egypt is named R. levantina sp. n. In this species the number of pulses/pulse group averages 11 and that of pulse groups/call 10. According to the phylogenetic analysis of the character states using parsimony, we conclude that R. perezi and R. levantina are sibling species forming an outgroup to the European sibling species R. ridibunda and R. balcanica.