Effect of agro-forestry and landscape changes on common buzzards (Buteo buteo) in the Alps: implications for conservation

In Italy, pre-Alpine forests, once managed through coppice silviculture, are being converted to mature woodland, while land abandonment is causing woodland expansion and erosion of open habitats. Based on habitat-selection analyses, we predicted the impact of such changes on common buzzards (Buteo buteo), which depend on forested and open areas for nesting and foraging. Compared to availability, at a micro-scale buzzards selected nests higher above ground and on trees frequently covered by ivy. At the landscape-scale, buzzards avoided roads and conspecifics, while selecting rugged areas with high habitat heterogeneity, probably related to a varied food supply. Productivity was related to the availability of arid habitats, probably because of their richness in main prey species. Finally, population density was negatively related to the abundance of eagle owls (Bubo bubo), a potential predator of adults and nestlings, and positively related to the availability of woodland, a low predation-risk habitat rich in food and nest-sites. Therefore, buzzard settlement, density and productivity depended on the complex interplay of food availability, human persecution and predation risk. Thus, the current landscape changes would benefit buzzards by providing more nest-sites, but would be detrimental because of the lower productivity associated with the disappearance of dry open areas. Proposed conservation guidelines focus on conversion of coppice woodland to mature forests and active management of dry heath, a conservation sensitive habitat, through controlled burning.