Effects of habitats fragmentation in a humandominated landscape France and mitigation measures to limit lynx Lynx lynx vehicle collisions

In the human-dominated landscape,land transport infrastructures can impact potentially large carnivore species, and in particular the Eurasian lynx (Lynx lynx), either with direct effects (habitats loss, increased accessibility of quiet areas and facilitation of poaching, vehicle collisions) or indirect effects (noise disturbance or human activity, habitats fragmentation, reduced and more isolated populations, loss of genetic diversity, etc.).

Our study investigated, firstly, the previous results of the most recent works in the field studies and modelling approaches of lynx and road infrastructures : habitat suitability model ; model to distinguish fragmentation and forest continuity, corridors and barriers ; local metapopulation viability and the dispersal model with assessment of management scenarios ; predicting model of the risk of collisions. We also used other single analyses and maps on the data set by the French National Game And Wildlife Agency completed and re visited (n=107 collision data between 1974-2014).

Within the Lynx range in France, including the Vosges, the Jura and the Alps, the lynx sub-populations and the factors fragmenting suitable habitats are quite well identified. The land transport infrastructures also cut the home range. They are barriers to dayly and seasonal movements that increase risk collisions. With poaching, they are the main causes of lynx mortality in France.

In this analysis, we investigate the three aim questions related to collision risk (1) Where ? When ? How do the mortality events occur ? (2) Do age and sex (juvenile, subadult, adult ; male or female) make a difference ? (3) Are there factors increasing the collision risk ? If yes, which are they ?

Finally, in a last part, we discuss some mitigation measures to limit the effects of fragmentation and road mortality. We analyse the main reasons of difficulties or unsuitability of the crossings and suggest some recommendations (subject to availability of complementary data and field experiments). Such scientific and practical results will improve the effectiveness of passages and related infrastructures (fences). It will be possible only by strongly encouraging a dialogue and future projects between all the stakeholders linked to this species and partners (managers, experts, scientists) either in road ecology and engineering or lynx studies.

Eurasian lynx, lynx lynx, France, human-dominated landscape, traffic-kills (roads and railroads), vehicle collisions, ecopassages, models and road planning, mitigation measures and projects