Molecular phylogeny and diversity of the Corsican red‐legged partridge: hybridization and management issues

Abstract

The red-legged partridge, Alectoris rufa (Phasianidae), is a game bird hunted throughout its range (Italy, France with Corsica Island, Iberian Peninsula). The release into the wild of farmed birds of unknown origin coupled to the hybridization with the exotic chukar Alectoris chukar (East Mediterranean to East Asia) has led to the reduction of the spatial component of genetic variability and to the pollution of the genome of A. rufa, respectively. On the mainland, A. chukar genes occur according a decreasing gradient from Italy to the Iberian Peninsula. Corsica hosts a number of A. rufa×A. chukar hybrids, but at a much lower incidence than nearby Italy. We sampled 97 red-legged partridges in different habitats of Corsica [lower-Mediterranean: Desertu di l'Agriate; rural: Nessa-Felicetu; mountainous: Vivariu-Venacu and Fium'Orbu-Taravu (FT)]. We investigated kinship between Corsican and continental A. rufa populations by sequencing the mitochondrial DNA (mtDNA) Cytochrome-b gene in a subset (n=60) of island specimens as well as in 105 partridges sampled on mainland Europe. All 97 Corsican partridges were genotyped at eight microsatellite DNA loci in order to estimate intraspecific relationships at a finer scale. We also used microsatellite data from previous studies to compare the genotypes of A. rufa reared in the only island farm with those of wild conspecifics. Corsican partridges grouped in the only statistically reliable and diverging mtDNA clade. Microsatellites provided evidence for the genetic isolation of the FT mountain population, whose low level of hybridization with A. chukar had been unveiled in a former paper. Both mtDNA and microsatellite markers revealed that released captive partridges did not enter the wild breeding populations to any great extent. We suggested banning A. rufa translocation from Corsica to the continent to comply with the disclosed genetic kinship, and vice versa to contain the spreading of A. chukar genes in to the A. rufa population.