The consequences of land sparing for birds in the United Kingdom

1. Land sparing has been proposed as a strategy to reconcile biodiversity conservation with agricultural production, with empirical studies on five continents indicating that most species would benefit if food demand was met through high-yield farming combined with the protection or restoration of natural habitat. 2. Most such studies come from landscapes covered by large areas of natural habitat and without a long history of intense human modification. However, much of Europe, consists of human-dominated landscapes, where biodiversity responses to land sparing may differ. To test this, we use estimates of bird population density in different (semi-)natural habitats, and forecasts of population density in farmland habitat, to assess the future consequences for birds of land-sparing scenarios in the United Kingdom. 3. Our scenarios predict that whilst up to 18 of the 156 species assessed (predominantly farmland associated species) might decline in UK conservation status under land sparing, up to 35 UK bird species (mainly woodland and wetland species) might improve in status. This contrasts with a maximum of 8 species likely to improve in conservation status without land sparing, with up to 7 species deteriorating. 4. Combining land sparing with demand management measures (reducing food waste and the consumption of animal products) led to more positive population changes under all scenarios. 5. Synthesis and applications. Land sparing has the potential to benefit UK bird populations in aggregate but would likely have negative impacts on farmland bird species. These findings are likely to be applicable across human-dominated landscapes beyond the UK, though effects on other taxa, implementation mechanisms, and the sustainability of higher yields all require careful consideration.