Genetic variation depends more on admixture than number of founders in reintroduced Alpine ibex populations

► Reintroductions aim to preserve much of the genetic diversity. ► We examine the impact of founder group composition on genetic diversity. ► Admixture in the founder group and founder group size affect genetic diversity. ► Admixture is more powerful than founder group size in increasing genetic variation. ► Releasing animals from different sources is important to preserve genetic diversity.