Since last century the red-legged partridge (Alectoris rufa, Galliformes), a species native to south western Europe, has been suffering from a strong demographic decline due to the increased use of pesticides and the deep change in the agricultural landscape, yet the strong hunting pressure, in particular, warranted the inclusion of the red-legged partridge into the list of Species of European Conservation Concern. More recently, the widespread genetic pollution due to the hybridisation with the congeneric chukar partridge (A. chukar) has represented a well-known additional threat, which could potentially result into the genetic extinction of the species. The aim of this study was to assess the genetic structure of wild A. r. rufa populations of Corsica in order to provide useful data for planning conservation actions. The Hunting Federation of High-Corsica (Bastia) collected 97 samples from birds hunted in the following areas of the island (2003-2007; liver fragment in 95% ethanol): Nessa-Felicetu (north western Corsica, n = 30), Desertu di l’Agriate (northern Corsica, n = 16), Vivariu-Venacu (central Corsica, n = 20), and Fium’Orbu-Taravu (central southern Corsica, n = 31). Mitochondrial DNA sequencing (Cytochrome-b) was performed for 37 Corsican partridges. Sequences were compared with those already available in the laboratory for the A. rufa specimens from Iberian Peninsula, France (mainland) and Italy, to get insight into the intra-specific genetic kinship. Phylogenetic reconstructions revealed a strong affiliation among Corsican individuals as well as their origin from French mainland. Furthermore, a total of all Corsican specimens (n = 97) were genotyped at eight loci of the microsatellite DNA originally isolated from either chicken (Wageningen University, The Netherlands: MCW 104, MCW 118, MCW 121, MCW 146, MCW 276, MCW 280) or red-legged partridge (Aru 1.23, Aru 1.27) genome. The partition of the genetic diversity was investigated by AMOVA (Analysis of Molecular Variance) using FST pairwise
distances. Estimations of possible departure from Hardy-Weinberg Equilibrium were carried out. Genetic diversity was significantly partitioned between (4.39%) and among (95.61%) Corsican populations, which, one exception apart, were all at HWE. In order to identify possible A. rufa x A. chukar hybrids, the Corsican representatives were compared with genetically homogeneus controls of both A. rufa (Portugal, Spain: n = 30) and A. chukar (Greece, Cyprus: n = 30) genotyped at the set of microsatellite loci. The Bayesian clustering procedure was used to carry out the genetic admixture analysis. Interestingly, the results produced weight for a very scarce if not null A. chukar gene introgression into the Corsican populations, thus highlighting their high conservation value for the A. rufa species.
