Habitat selection in a changing environment: the relationship between habitat alteration and Scops Owl (Aves: Strigidae) territory occupancy

Abstract

The Scops Owl Otus scops (L., 1758) is a species of European concern, which suffered a noticeable decrease in distribution in the last decades, and changes in agricultural practices have been proposed as a major threat for this owl. We studied the habitat preference of the Scops Owl by assessing the habitat occupancy of 401 territories distributed in a large area in northwest Italy, with a special focus on 98 territories located in a high-density area (Monferrato). Habitat characteristics were analyzed with maximum entropy (MAXENT) models that included both vegetational (16 land use categories) and physical features estimated from a Digital Terrain Model (DTM) (altitude, slope, hillshade). In the Monferrato area, a comparison of 2009 landcover was also made with year 1954/55 characteristics obtained from aerial photographs. In the full northwest Italy area, the Scops Owl preferred areas located at middle altitude with intermediate slope. The preferred habitats included riparian areas and pasture-grassland, while woodlands and zones with Robinia pseudoacacia shrublands were avoided. In the Monferrato area, Scops Owl occupancy occurred in sites where the landuse (croplands/vineyard mosaic) had changed little since the mid-1950s. Our study suggests that conservation activity should focus on interventions halting riparian zone transformation and subsidies promoting agricultural practices favouring pastures and grassland.