EN
The S-type vocalizations of three populations of Ctenomys from Uruguay were compared: two of Ctenomys pearsoni Lessa and Langguth, 1983 from Penino and Relincho and the third from a different karyomorph of the genus (Solis karyomorph). Ten rhythm and 3 frequency variables were used for discriminant analysis. The results showed that a set of nine variables allowed a complete separation of the populations. The two C. pearsoni populations were correctly discriminated from one another using four variables, the differences lying especially in the rhythm domain. Information about the general biology and distribution of the animals suggest that these differences could be explained as a product of chance variations and later fixation of the variants in local populations. The Solis karyomorph was also correctly discriminated from the other populations using four variables, but main frequency seems to play an important role in this case.