Vocal signatures of the rally call of red-legged and rock partridges and of their hybrids

Red-legged (Alectoris rufa) and rock (A. graeca) partridges are two species belonging to the same genus, which hybridise at a contact zone located in the southern Alps. Hybrids are viable and fertile. Male rally calls (implic ated in species isolation mechanisms) of the two species and their F1 hybri ds were analysed and compared. Three temporal and frequency parameters were studied. Of all parameters studied, principal components analysis revealed that male rock partridge signals present a reduced stereotypy compared to those of the male red-legged partridge. It also indicated that the frequenc y of the maximum amplitude and the frequency band containing 80 % of the en ergy are the factors that differ the most between the two species. F1 hybri d males present an intermediate profile. These results are discussed in ter ms of species barrier problems within the Alectoris lineage. (C) 1999 Acade mie des sciences / Editions scientifiques et medicales Elsevier SAS.