Anthropogenic and natural fragmentations shape the spatial distribution and genetic diversity of roe deer in the marginal area of its geographic range

Habitat destruction and fragmentation are major factors in the destruction of genetic diversity and affect the movement behavior of the Roe deer population in the remaining habitats. Here, we study the population and landscape genetics of Capreolus capreolus (roe deer) in northern and northwestern Iran using twelve polymorphism microsatellite markers. From 111 total specimens, 63 had successful extraction (6 feces, 35 tissues, 9 bones, and 13 antlers). We considered 30 microsatellite polymorphic loci, of which only 12 were amplified for our further analysis. For genetic diversity analysis, the Weir-Cockerham method was applied to measure the inbreeding coefficient (FIS) and fixation index (FST) for each locus as well as for each population. For landscape genetics, the susceptibility patterns of genetic variations were assessed using three hypotheses including isolation by distance (IBD), isolation by environment (IBE), isolation by resistance (IBR), and individual landscape genetic analysis. A habitat suitability map as an indicator of landscape resistance was constructed from several species distribution models (SDMs) algorithms including Generalized Boosting Models (GBM), Maximum Entropy (Maxent), Random Forest (RF), Generalized Linear Model (GLM), Multivariate Adaptive Regression Splines (MARS) and artificial neural networks (ANN) and an ensemble model. Our estimated FIs index showed that the Golestan, Arasbaran, and Guilan populations had the highest and lowest genetic diversity among roe deer populations. According to the Fst criterion, our results showed that Golestan and East Azarbaijan (Arasbaran) had the highest and Mazandaran had the lowest genetic distance patterns. Our results do not suggest that there is high genetic differentiation for roe deer in the region, with high levels of gene flow between study areas. We found that geographic distance has no significant relationship with genetic distance and that there is no significant relationship between the ecological niche non-similarity matrix and the genetic distance matrix. The most influential factors affecting gene flow in roe deer were aspect and elevation variables. The analysis suggests that the landscape has no significant influence on the structuring of the studied population and shows little genetic differentiation.