Agricultural intensification and the extinction of semi-natural habitats at the fringes of fields have led to a general decline of bird communities in European farming landscapes. Their conservation has become a major issue for agricultural regions, especially where viticulture prevails, because of both the essential services they bring to farmers, such as the regulation of pests, and their patrimonial and cultural value. An international team coordinated by INRAE, also involving the Bordeaux Sciences Agro and l’École Supérieure d’Angers (ESA), studied avian communities in 334 vineyards spread over 12 French, Spanish, and Italian viticultural regions. Their results, published May 11, 2021, in the Journal of Applied Ecology, show that the diversity of avian communities is enabled by a combination of organic vineyards, grassy shelters between rows of vines, and diversity of surrounding habitats (forests, hedges, grasslands, etc.).
Like all farming, vine-growing depends on the fulfillment of many needs accomplished by the vineyard’s biodiversity. Birds are an essential component of this biodiversity since, by consuming them, they regulate pests and invasive species. Furthermore, they represent a great cultural and patrimonial value, mostly through their song and the diversity of soundscapes they bring to viticultural landscapes. Winemaking intensification and a growing uniformity of viticultural landscapes has led to a decline of avian communities, and their preservation has become a major issue in Europe. Along with the necessity of moving toward sustainable agriculture, more and more wineries are committing to environmentally friendly farming practices such as the ones listed in the books of requirements for organic agricultural certification (e.g., refraining from using artificial fertilizer or pesticide), preservation of semi-natural habitats (hedges, bushes, etc.), and non-intervention in these habitats during nesting and/or breeding periods. However, it should be noted that the effect of combining these practices on the diversity of avian communities was never studied on a large geographical scale.
Researchers thus studied communities of birds in 334 vineyards, of which 30% are organic, in 12 European viticultural regions with contrasting landscapes and climates. For example, these regions include the South of Catalonia in Spain, Nouvelle Aquitaine, Bourgogne-Franche Comté, and the Loire region in France, as well as the North of Italy. In each of these vineyards, they identified the species of birds present and counted singing individuals of all species to analyze the diversity of each community and the ecological functions and services they could bring. For instance, the presence of insect-eating species such as chickadees, or of grain-eating species, such as sparrows, are a precious help for wineries because they can contribute to regulating pests and weeds. On the contrary, fruit-eating birds can be problematic.
The international team surveyed more than 11,500 individuals belonging to 131 species, including threatened ones like the Ortolan bunting or the little bustard. The results of this study show that abundance of bird species relies on practical combinations that vary according to the species’ characteristics. Therefore, environmentally friendly wine-growing practices allow for an abundance of insect-eating birds and diversity of avian communities, but this effect is reinforced by grassy rows between vines and variety of the landscape. Additionally, an elevated percentage of forests streaking the landscape attracts a myriad of insectivores and avian species with enjoyable song. This environment, however, is less attractive to grain-eating birds and those accustomed to large spaces, who prefer a sizeable proportion of vines.
The results of this study clearly indicate that a transition of viticulture towards more sustainable systems that respect biodiversity must rely on several methods simultaneously: promote organic winemaking as well as other agroecological practices such as vines’ integration of grassy patches, and preservation of the diversity of landscapes, notably the presence of forests, hedges, grasslands, and other crops.