Résumé
Context: Linear Transportation Infrastructures (LTIs) are among the largest factors responsible for landscape fragmentation, in turn increasing population isolation. In this context, studies have mainly focused on a single species’ response to barrier elements and mitigation thereof. Yet, the implementation of conservation strategies to restore landscape connectivity may be challenging when multi-specific responses are not measured and fully considered.Objectives: We aimed to assess the effect of two different types of LTIs, a fenced highway and a navigation canal on gene flow in three ungulate species in Northeastern France.Methods:We genotyped 98 red deer (C. elaphus), 120 wild boars (S. scrofa) and 140 roe deer (C. capreolus) with species-specific microsatellite markers from 3 sampling sites located on either side of both LTIs considered in the study area. We assessed the continuity of gene flow using Bayesian clustering methods and a mapping approach to determine inter-individual genetic dissimilarity in relation to landscape characteristics.Results:Our study showed different impacts of LTIs on the gene flow of species belonging a priori to the same functional group. Genetic differentiation among red deer and wild boar sampling units was observed on either side of the highway, but no such differentiation was identified for roe deer. However, no genetic structuring was associated with the presence of the canal in any species.Conclusions: The impact of LTIs on gene flow in large species results from the structural characteristics of the infrastructure, and our study shows that mitigation measures should consider species-specific behaviors to facilitate the use of crossing structures and thus ensure gene flow across ILTs.