Hugging the hedges: Might agri-environment manipulations affect landscape permeability for hedgehogs?

Semi-natural agricultural habitats have declined in northern Europe since the 1950s, to the detriment of habitat connectivity and biodiversity. European agri-environmental schemes to restore them should target the habitats most likely to remedy these impacts. We employed a stochastic individual-based simulation model to predict movements of a model species, the European hedgehog (Erinaceus europaeus), across a series of virtual landscapes - digitised from a typical UK lowland agricultural area - in which the abundance of hedgerow, pasture fields and field margin had been manipulated according to a factorial design. The primary landscape determinant of distances that model hedgehogs travelled was the percentage of field boundaries that were hedgerow: doubling this from the status quo resulted in an additional 13% of individuals moving 500 m, 25% 1000 m, 35% 1500 m and 51% 2000 m. Trebling the percentage of hedge yielded no additional benefit over doubling it (mean additional percentage 0.6%). Doubling the landscape percentage of pastures resulted in a 1% increase in model individuals moving 500 m and 1000 m, but decreases for 1500 m and 2000 m (-2% and -4%, respectively). Increasing the percentage of hedged fields that also had field margins led to decreases of -1% to -8% in individuals moving any distance. Agri-environmental scheme options to reinstate or repair hedges that double their percentage in lowland farmland would enhance population connectivity for European hedgehogs. Further work should extend these individual-based models to representative sets of species to explore the extent to which management for one species may benefit others.