The rich birdlife of vineyards

Sunny slopes with southern exposure at low altitudes, influenced by a continental climate, offer the best conditions for winegrowing in Switzerland. Although grapes were already grown in Valais some 2000 years ago, the 20th century in particular saw a significant expansion of viticulture. Natural habitats such as rocky steppes and dry, open woodland, but also traditionally managed land (traditional orchards, low-intensity meadows and pastures) disappeared to make way for vineyards. Today, row upon row of vines dominate the landscape in many areas, especially in the dry, inner-Alpine valleys (Valais, Rhine Valley), around Lake Geneva and on the southern slopes of the Jura. About 157 km² of land is classified as vineyards, or about 1.5 % of agricultural land. But despite the small surface area and often intensive cultivation methods, vineyards can be important local habitats for rare birds.

Valuable landscape elements in vineyards

Dry-stone walls, free-standing bushes, low hedges and patches of dry, species-rich grassland are important habitat structures for birds whose declining population trend makes them candidates for special conservation projects. Examples of these priority species are Common Redstart and Red-backed Shrike. However, the landscape elements alone are often insufficient to promote populations in an effective way. Only when combined with sustainable and biodiversity-friendly cultivation practices can their positive effects take hold. On the plots themselves, species-rich ground vegetation with an abundant supply of insects for food is the most important measure to promote biodiversity, which in turn requires reducing the use of herbicides. Woodlark and Common Linnet are typical breeding birds that have benefited from the increased ground vegetation in vineyards in recent decades.

For the Swiss populations of Woodlark, Eurasian Wryneck and Common Hoopoe, vineyards are an important habitat type. During the breeding season, these birds preferably forage in vineyards with partial ground cover, where insects are easily detected and caught on the ground and in sparse vegetation. Ideally, about 50 % of the ground should be covered, meaning there is ground vegetation in every other row. In the case of the Woodlark, this preference applies to foraging sites; its preferred nest sites, on the other hand, are in dense and tall ground vegetation. Therefore, the changing requirements of the Woodlark during its life cycle are best met by a mosaic of vegetation structures, arising from natural succession. Eurasian Wryneck and Common Hoopoe need plenty of short vegetation so that insect prey remains accessible. Alternating mowing or tilling in every other row keeps ground vegetation short and promotes a variety of vegetation structures.

The Cirl Bunting is another priority species whose population is concentrated in richly structured vineyards, especially on the southern Jura slopes, around Lake Geneva and in central Valais. In these areas, free-standing trees and bushes offer cover and nest sites, while vineyards with ground vegetation provide a year-round supply of food.

Diverse birdlife during the winter months

In winter, vineyards – often remaining snow-free due to their southern exposure – are occupied by finches (e.g. Common Chaffinch, European Greenfinch, European Goldfinch, European Serin) and thrushes (e.g. Mistle Thrush, Fieldfare). The preference for small habitat structures, especially hedges and copses, is even more pronounced in winter than in summer. Species-rich ground vegetation plays a central role in winter as well; during the winter months, continuous vegetation cover is preferred. Thus, partial ground vegetation, covering the ground beneath every other row, is a good compromise in view of meeting the ecological requirements of different species all year round.

A diverse future?

The future of biodiversity in vineyards is uncertain. The spread of settlements continues to fragment our landscapes, and winegrowing regions are no exception. South-facing slopes, rich in plant and animal species, are built up by housing developments. The fragmentation and loss of vineyards has dire consequences for biodiversity. But there are glimmers of hope; thanks to financial incentives, vineyards with ground vegetation and small habitat structures have steadily increased in area in Switzerland over the past few years. It is encouraging that even in Valais, where ground vegetation is not required because there is little rainfall, about 20 % of vineyard area (approximately 10 km²) has a herb cover. Hopefully, sustainable production practices, resulting in ground vegetation in vineyards and a reduction in the use of pesticides, will lead to the long-term conservation of ecologically valuable cultivated landscapes – to the benefit of the human population and threatened bird communities alike.