Buntings (Emberizidae) as indicators of HNV of farmlands: a case of study in Central Italy

Farmlands represent one of the most important habitats for several bird species in Europe, but during the last few decades, agricultural landscapes have been subject to a rapid and large-scale change, caused by the intensification and mechanization of agricultural activities, that is one of the main drivers of worldwide biodiversity decline. The high nature value farmlands (HNV) are characterized through three criteria: low-intensity farming, presence of residual semi-natural vegetation (hedgerows, uncultivated, shrubs, scattered trees, marginal uncultivated) and diversity of land cover mosaic; values that are often correlated with highest farmland bird diversity. In this work, we used Generalized Linear Models to evaluate the presence of different bunting species, typical of farmlands in Central Italy, as potential indicators of HNV of farmland and surrogates of landscape heterogeneity. Our results showed how the presence of bunting species is associated with markedly different environmental parameters. A species which could potentially be more useful for identifying HNV farmlands (more heterogeneous landscape, supporting also greater bird species richness) is the Cirl Bunting. The Corn Bunting and Ortolan Bunting were less predictive as indicators of farmland heterogeneity. Ortolan Bunting was unrelated to the complexity of farmlands and bird richness. This information is important for the planning of large-scale conservation policies and to increase our understanding of farmland bird indicators.