Land use changes and raptor population trends: a twelve-year monitoring of two common species in agricultural landscapes of Western France.

There are serious concerns about the ecological degradation caused by modern agriculture and its impact on top-chains predators. But, scientists still disagree how to assess which winners losers of Anthropocene biodiversity changes. In this field research, many studies have been carried out passerine birds but long-term ones, especially raptors, missing. Our study reports a twelve-year survey two diurnal common raptors (the Buzzard, Buteo buteo Eurasian kestrel, Falco tinnunculus) facing recent land use changes in Western France farmland landscapes. Precise remote sensing data were analyzed each year, allowing us precisely describe stability along time series. Buzzards showed reduced abundances intensified landscapes responded negatively wood habitat instability while kestrels more abundant stable when areas meadows increased. According life history traits these two-raptor species, we may suppose that buzzards, as generalist predators, mainly suffer nesting site decrease food depletion namely voles living meadows. No decreasing or increasing regional local trends was observed for buzzards during 12-years confirming populations seem adjust their numbers fit resources. Inversely, exhibit significant population collapses at both scales. If limiting habitats fragmentation disturbance would optimize buzzard densities, drastic management measures improving surfaces quality grassland will be necessary reverse decline highlighted study.