Responses of aerial insectivorous bats to landscape composition and heterogeneity in organic vineyards

Landscape composition and heterogeneity are considered important factors for enhancing biodiversity and their associated ecosystem services in human-modified landscapes. Despite their roles in pest suppression in agricultural areas, insectivorous bats have been poorly represented in studies assessing the effects of landscape structural changes, particularly in the Neotropics. We evaluated how the composition and heterogeneity of the landscape, at several spatial scales, influenced the diversity and activity of aerial insectivorous bats in organic vineyards. Bat activity was quantified using acoustic surveys at 16 vineyards distributed across the central zone of Chile, where landscape composition and heterogeneity were determined by spatial analysis (GIS). Data were analyzed using partial least square regressions (PLS). The diversity and activity of aerial insectivorous bats in vineyards increased with the compositional and configurational heterogeneity of the landscape. Bat diversity and species richness in vineyards increased as the area covered by native vegetation increased, and urban areas decreased. Total bat activity, feeding activity and the activity of the dominant species T. brasiliensis increased with the diversity of cover types in the landscape, and also as the area covered by annual crops and rural areas increased. This study highlights the importance of agricultural landscape composition and heterogeneity for aerial insectivorous bats in organic vineyards. Effective conservation efforts and management strategies in this crop should aim to increase cover diversification at the landscape scale. In addition, retaining native forest remnants around or within vineyards may promote bat conservation and their role as suppressors of crop pests in these production landscapes.