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The long-term success of species reintroductions is strongly dependent on the availability of large areas of suitable habitat and the genetic make-up of the population. If available habitat is poorly connected this can hinder gene flow and lead to genetic fragmentation of the population, potentially increasing its extinction risk. We employed a conservation genomics approach in which we combined analyses of genetic structure with testing for potential landscape effects on habitat selection and gene flow in reintroduced Asiatic wild ass Equus hemionus ssp. in the Israeli Negev desert. Genetic structure and pairwise relatedness were first investigated followed by examination of landscape effects on individual habitat selection using records of GPS collared individuals. We then built habitat resistance surfaces and used electrical circuit theory to test for landscape effects on genetic relatedness. We detected weak genetic structuring, yet low spatial coherence among individuals from the same genetic cluster. Landscape variables had a significant impact on individual habitat selection, with wild ass avoiding steep slopes and habitats of low suitability as predicted by a species distribution model. However, the landscape genetic analysis revealed no effect of habitat resistance on genetic relatedness. These results suggest that gene flow in the reintroduced population is not impacted by landscape resistance. Indeed, the high mobility of the species may increase its resistance to the genetic effects of habitat fragmentation, at least over a small number of generations. We discuss other potential causes for the observed genetic structure including a behavioural effect. Our study highlights the importance of understanding species-habitat interactions for the long-term success of reintroductions.

In a reintroduced population, the social behavior of the species can strongly affect the long-term viability of the population through its effects on movement, information flow, disease spread and the population's genetic variability. Therefore, information on the social behavior of a reintroduced population can contribute to conservation practices; however, its importance is often underestimated. The initial phase of the Asiatic wild ass's (Equus hemionus) reintroduction in Israel has been considered a success, and the population is currently estimated at more than 250 individuals. However, the current social structure of the population remained unknown. We aimed to study this important population trait and to provide helpful information for efficient conservation and management protocols. The study was based on direct observations that were conducted over four consecutive years, and on the analyses of groups' composition and female groups' stability. Female groups accompanied by males constituted only 5% of the total 659 observations, males were observed to be mainly solitary or in groups of various sizes, and females were organized in non-stable groups, indicating that the reintroduced population exhibits a fission-fusion social structure. Identifying the social structure for the species in the expanding Negev population of the Asiatic wild ass can assist in implementing future reintroductions and can contribute to effective management decisions aimed at protecting the species.

Summary Successfully reintroduced species offer an exceptional opportunity to study the rules that govern population range expansion. We suggest that models that are based on knowledge of space-use patterns of reintroduced species can be used as projection models in the context of landscape planning. We illustrate this idea through a case study in which we used the population range-expansion patterns of Persian fallow deer ( Dama mesopotamica ) reintroduced in northern Israel, to explore potential impact of landscape development on species space-use patterns. In this approach we used an individual-based spatially explicit model that simulates species range expansion on a realistic landscape. We previously validated the model over the short-term (5 years) and apply it here for long-term, 50-year, projections using two scenarios: (1) current landscape conditions; and (2) the government's development plans for the region. Based on the long-term projections using the current landscape, we identified and mapped preferred deer habitat in which population activity centres were established. By applying the model to the government's development scenario for the region we examined the potential effect of landscape development on habitat availability and the future spatial distribution of the deer. By comparing the outputs from both scenarios threats to landscape connectivity could be identified. A map presenting key areas for landscape connectivity, important for the reintroduced species, can be used for long-term planning of local and regional development. Under the umbrella paradigm, protecting these areas may help to also conserve other species in the same ecosystem.