Landscape genetics matches with behavioral ecology and brings new insight on the functional connectivity in Mediterranean mouflon

Abstract

In natural populations, gene flow often represents a key factor in determining and maintaining genetic diversity. In a worldwide context of habitat fragmentation, assessing the relative contribution of landscape features to gene flow thus appears crucial for sustainable management of species. We addressed this issue in Mediterranean mouflon (Ovis gmelini musimon × Ovis sp.) by combining previous knowledge on behavioral ecology with landscape genetics. We also assessed how sex-specific behavioral differences translated in term of functional connectivity in both sexes. We relied on 239 individuals genotyped at 16 microsatellite markers. We applied a model optimization approach in a causal modeling framework of landscape genetics to test for the effects on gene flow of habitat types and linear landscape features previously identified as important for movements and habitat selection in both sexes. Five resistance values were alternately assigned to these landscape characteristics leading to a comprehensive set of resistance surfaces. Isolation by resistance shaped female gene flow, supporting the central role of linear landscape features as behavioral barriers for animal movements. Conversely, no isolation by resistance was detected in males. Although a lack of statistical power cannot be discarded to explain this result, it tended to confirm that males are less influenced by landscape structures during the mating period. Combining previous knowledge on behavioral ecology with results from landscape genetics was decisive in assessing functional landscape connectivity in both sexes. These results highlighted the need to perform sex-specific studies for management and conservation of dimorphic species.