Genetic structure in Iberian and Moroccan populations of the globally threatened great bustard Otis tarda: a microsatellite perspective
Jose Luis Horreo, Juan Carlos Alonso, Carlos Palacín, Borja Milá
Patterns of genetic structure and gene flow among populations help us understand population dynamics and properly manage species of concern. Matrilineal mtDNA sequence data have been instrumental in revealing genetic structure at the intraspecific level, but bi-parentally inherited markers are needed to confirm patterns at the genome level and to assess the potential role of sex-biased dispersal on gene flow, particularly in species where males are known to be the main dispersing sex. Here we use microsatellite loci to examine patterns of genetic structure across the range of the great bustard in Iberia and Morocco, an area representing 70% of the world population of this globally threatened species. We used population differentiation statistics and Bayesian analysis of population structure to analyse data from 14 microsatellite loci. These data provide greater resolution than mtDNA sequences, and results reveal the existence of three main genetic units corresponding to Morocco, the northeastern part of Spain, and the rest of the Iberian Peninsula. Our results, together with previous mtDNA data, confirm the genetic differentiation of the northern Africa population and the importance of the Strait of Gibraltar as a barrier to gene flow for both males and females, rendering the Moroccan population a separate management unit of high conservation concern.