The occurrence of a flagship raptor species in intensive agroecosystems is associated with more diverse farmland bird communities: Opportunities for market-based conservation

Traditional livestock systems have supported farmland biodiversity for millennia. However, modern intensivehusbandry is challenging wildlife persistence in agroecosystems. We assessed the multiscale determinants of thespecies richness of breeding bird communities, as well as the occurrence of a flagship raptor species, the lesserkestrel Falco naumanni, in an intensive agroecosystem mostly dedicated to the production of the world-renownedParmigiano Reggiano cheese. We relied on three avian community richness metrics reflecting a gradient ofincreasing association with farmed landscapes, i.e. the overall breeding bird species richness, the richness offarmland species, and the richness of ground-nesters (i.e. species that mostly breed within crops) and tested theirassociation with the landscape, agricultural, and pedological variables as well as with lesser kestrel occurrence.We showed that environmental variables determining overall richer avian assemblages did not coincide withthose shaping farmland and ground-nesting species richness, thus challenging the potential effectiveness ofconservation actions. However, such actions could be optimized by taking into account different spatial scalesaffecting different species groups. Indeed, landscape heterogeneity, semi-natural/marginal habitats, and amoderate cover of build-up areas enhanced overall species richness at a small spatial scale. At a broader scale,landscape heterogeneity enhanced farmland species richness, whereas fragmentation determined by urbanizationnegatively affected ground-nesters. Avian community richness metrics were maximized at an intermediatecover of three prevailing crops (winter, summer, and hay crops), increasing when they co-occurred, i.e., in thepresence of crop rotation. Lesser kestrel occurrence was associated with richer assemblages of ground-nestingspecies because this raptor and ground-nesters showed analogous ecological requirements. These findings suggestthat the lesser kestrel can be regarded as an ideal flagship for market-based conservation initiatives (e.g.,tailored to the production of biodiversity-friendly agri-food products) in intensive agroecosystems since actionsaimed at improving the foraging habitats of the species are likely to benefit co-occurring farmland birds ofconservation interest.