Utility of island populations in reintroduction programs—relationships between Arabian gazelles (Gazella arabica) from the Farasan Archipelago and endangered mainland populations

Understanding local adaptation and population differentiation is vital to the success of reintroduction initiatives. Like other mammals living on islands, Arabian gazelles (G. arabica) show reduced body size on the Farasan archipelago, which we corroborated in this study through morphometric analyses of skulls. In light of the steep population decline on the Arabian Peninsula—but stable population development on the archipelago—we tested the potential suitability of Farasan gazelles as a source for reintroductions on the mainland. We, therefore, investigated genetic differentiation between Farasan and mainland populations using eleven nuclear microsatellite loci and detected a distinct genetic cluster exclusively present on the archipelago, which we inferred to be separated from the mainland cluster for less than 2,000 years. About 30% of sampled individuals from Farasan Islands showed assignment to a mainland cluster with signs of ongoing introgression. Analyses using the Isolation-wit...