Roads, forestry plantations and hedgerows affect badger occupancy in intensive Mediterranean farmland

Abstract

There is increasing interest in understanding how to retain wildlife in agricultural landscapes, thereby contributing to global biodiversity conservation efforts. Here we investigate the drivers of European badger (Meles meles) occurrence in Mediterranean farmland. The badger is a generalist mammalian carnivore usually associated to native woodland and shrubland, so we hypothesised that its occurrence in Mediterranean farmland should be favoured by substitute habitats such as forestry plantations, and negatively affected by areas more heavily used by humans such as paved roads. The study was conducted in SW Portugal, where we surveyed for badgers presence signs (latrines, footprints, setts) along transects located at 60 3.14-km2 circles scattered through the landscape, each of which surveyed in spring (March-May), summer (July-August) and autumn (September-October). Occupancy-detection models were used to quantify the effect of environmental variables on badger occupancy probability, while controlling for imperfect detection. Badger detection probability was positively affected by the density of dirt roads, possibly reflecting a preference of badgers to mark along those structures. According to predictions, badger occupancy significantly increased with the amount of forestry plantations and arboreal hedgerows, while decreasing with increasing paved road density. Taken together, our results indicate that badger conservation in Mediterranean farmland under agricultural intensification should require the protection of areas with low paved road density, and the retention of wood cover, even where these are highly-modified habitats such as forest plantations and arboreal hedgerows.