Contrasting effect of isolation of hedges from forests on farmland vs. woodland birds

Abstract

Hedges and forest edges play a major role in providing nesting sites, food resources and shelter for birds in agricultural landscapes of western and central Europe. We investigated the response of farmland vs. woodland birds at two degrees of isolation of hedges from forest and to vegetation structure. We surveyed 200 m long sections of six forest edges, six hedges connected to forests and six isolated hedges. Species richness and abundance of farmland birds were higher in hedges than in forest edges, species richness and abundance of woodland birds were lower in hedges than in the forest edges. Species richness and abundance of both groups did not differ between connected and isolated hedges. Width and height of hedges and edges did not affect the species richness and abundance of either farmland or woodland birds. Furthermore, bird community composition differed between habitat types (hedge vs. forest edge) and also between hedge isolation levels (hedges connected to forest vs. isolated hedges). Based on our results, we emphasize the importance of hedges in conserving farmland birds and encourage policy makers to support hedge creation and maintenance with landscape-wide management strategies supporting a diverse hedge structure. Both connected and isolated hedges play an important role as they harbour different bird communities. © Akadémiai Kiadó, Budapest.