Fine-scale habitat utilization by birds in an ancient oak (Quercus spp.) wood-pasture in southwestern Turkey

Abstract

Wood-pastures are disappearing rapidly in the eastern Mediterranean basin due to changes in land use. Traditional farming by means of goat husbandry and pollarding has allowed many trees to become old, creating valuable habitats for biodiversity. Developing viable management schemes for habitats of conservation concern require studies aiming at identifying relationships between habitat structure and associated species. In this study, the associations between habitat structure and bird species diversity were studied on a fine scale, using data obtained from transect inventories in an oak wood-pasture in southwestern Turkey. Almost all species were most abundant where trunk size, basal area or tree density peaked. Diversity of ground-nesters was slightly and positively associated with an increase in basal area. Low canopy-nesters were positively associated with an increase in shrub density, whereas there was a negative association for high canopy-nesters. Secondary cavity-nesters were unrelated to the density of small trunk cavities but exhibited a positive association with basal area of trees. Contrarily, primary cavity-nesters preferred trees with larger cavities, although this was most likely due to the presence of other desirable attributes of the very same trees. The results of this study give important insights to the structural and spatial organization of bird assemblages in a little studied but rich, culturally managed ecosystem in the Mediterranean.