Predicted decline in common bird and butterfly species even under conservation policy scenarios in Europe.

In response to increasing human pressures on biodiversity, conservation targets have been set to reduce these pressures and halt biodiversity decline. However, consequences of these objectives on common species are rarely studied. We analyse the effect of a range of drivers related to climate, land use and land-use intensity on 265 common bird and 144 common butterfly species from more than 20,000 sites between 2000 and 2021 across 27 European countries. We use land use and land-use intensity scenarios produced previously using the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Nature Futures Framework and climate change scenarios to project biodiversity drivers in Europe up to 2050. We translate these driver changes into abundance variations for common bird and butterfly species and for multi-species indicators used to monitor common biodiversity status in Europe. The projected trends relatively improve, while still declining for birds, notably farmland species, under the scenarios meeting conservation objectives, with few effects on butterflies. No scenario shows a stop or a reversal in the average decline in abundance of bird and butterfly species. Our results therefore question the common biodiversity future under current conservation policies and highlight the need for other anticipatory frameworks not implicitly based on a growing need for natural resources.