Response of the small mammal community to changes in western French agricultural landscapes

We studied the response of the small mammal community (rodents and shrews) to recent changes in agricultural systems of western French landscapes. Work was conducted on twelve sites representative of the diversity of farming systems in this region. The characteristics of small mammal assemblages in each site were assessed using Barn Owl (Tyto alba) pellet analysis. Relationships between small mammal data and landscape descriptors were performed through co-inertia analysis. Richness and specific composition of the small mammal community were not affected by the degree of cultivation but variations in species frequency could be observed. The prevalence of some species allowed us to distinguish three main assemblages which were characteristic of low, medium, and high intensified landscapes. Status and life traits of these species showed that intensification of agriculture has negative effects on density of rare and habitat-specialist species while it favours habitat-generalist species, some of them being known to exhibit fluctuating density. The two main ways of agricultural intensification (maize vs. other crops) did not show any significant relationships with species assemblages. Our results gave us the opportunity to suggest recommendations on agronomical and conservation problems that may arise from these changes of agriculture in western France.