Crop-land simplification impacts differently on small mammal communities: evidence from diversity/dominance plots using Barn Owl (Tyto alba) pellets

The land transformation of traditional agro-mosaics into progressively more anthropized crops can trigger changes in small mammal communities. Here, we reported data about a treatment–control comparison between small mammal communities preyed by the Barn Owl (Tyto alba) in two sites showing different levels of anthropization: simplified crop mosaic (treatment site; ANT) versus a high heterogeneous mosaic (control; CTR). Data from owl’s pellets showed as normalized richness, Shannon–Wiener diversity, evenness, and trophic level were lower in ANT when compared to CTR. Due to: (1) the strong reduction in shrews (Eulipotyphla) of higher trophic level, and to: (2) the higher frequency of the first dominant species (Microtus savii), the diversity/dominance diagrams plot lines appear steeper in ANT. Moreover, comparison of abundance and biomass patterns both in Whittaker and in k-dominance plots, showed a higher sensitivity of abundance to crop-land simplification, when compared to biomass. Although, shrews appear sensitive to the use of chemical compounds in agriculture, in our study the cropland management in ANT is based on ‘organic farm’ approach, without use of chemicals. In this regard, we propose alternative processes to explain the shrew reduction.