The value of agri-environment schemes for macro-invertebrate feeders: Hedgehogs on arable farms in Britain

Agri-environment schemes have been introduced in countries throughout the world in an attempt to reverse the negative impacts of agricultural intensification on biodiversity and the environment. There have been some investigations into the effectiveness of such schemes, which show mixed outcomes but little is known with regard to mammals. The hedgehog is a generalist predator and preys on, among others, an array of macro-invertebrates, prey important for many other taxa. For a non-volant species, it is highly mobile in the environment and should thus be less susceptible to negative effects of habitat fragmentation caused by agricultural intensification. However, it has recently been included in the UK Biodiversity Action Plan, as a result of evidence of a significant decline. We studied the importance of agri-environment schemes for hedgehogs using radio-tracking on arable farms. Both agri-environment field margins and hedgerows appear to be very valuable for hedgehogs. Both habitat types were intensively utilized by hedgehogs; higher food availability/accessibility on agri-environment field margins and higher food or nest site availability along edges and/or lower predation risk by badgers in arable areas may explain these preferences. Badger predation of hedgehogs was high in the study site and the main cause of death. Our study emphasizes the importance of natural habitat in an agricultural landscape and shows that agri-environment schemes can be beneficial to this generalist macro-invertebrate feeder. The implementation of agri-environment schemes that include wide field margins and dense, well-established hedgerows on farmland could significantly contribute to the viability of hedgehog populations in intensive arable-farming landscapes, and by implication benefit other macro-invertebrate feeders.