Populations of deer (Cervus elaphus) have always existed around Paris, in the many forests near the capital. The development of urban areas and the realization of large linear transport infrastructures have completely changed the spatial organization of the deer populations.
To assess the impact of this fragmentation of the landscape on the spatial structure of the deer populations, and also the permeability of the transport infrastructures, two complementary approaches were used. The first, through field observations, was to conduct a study of the use of the habitats by the deer over more than 50 years, covering c. 60 000 ha. The second approach being a landscape genetic study, between 2013 - 2015 on a sample of 345 individuals.
The study of habitat use shows that new population nuclei appeared in previously unused areas. In parallel, the deer have left the state forests, open to the public, to concentrate in private forests, apparently because of disturbance in their previous forest refuges. In the Paris region, large numbers of people with more free time and more cars have occupied the peri-urban forests since the 1980s. Genetic analyses show that the fragmentation of the landscape was accompanied by differentiation of the deer populations. Further, the results show the beneficial role of wildlife passages over the infrastructures, and reveal the remarkable reactivity of deer in an environment that has completely changed in fifty years. The Paris region provides an exceptional field laboratory for studying the interactions between landscape fragmentation and red deer, and very likely for other species too.
red deer, impact, wildlife passage, landscape genetics