Predicted decline in common bird and butterfly species despite conservation policy scenarios in Europe

Protecting common biodiversity: a major challenge for Europe

European biodiversity conservation policies have been in place for decades. Although they have helped reduce some direct pressures, they have largely focused on threatened species, leaving less attention to the wider ecological conditions and processes that sustain biodiversity across landscapes.. As common species of birds and butterflies are not specifically targeted, they fall outside the scope of these conservation measures, even though they are essential to the functioning of agricultural, forest and grassland ecosystems and serve as indicators of environmental health. Their decline undermines the functioning of ecosystems and may signal a shift towards threatened species status. 

In response to these growing threats to biodiversity, conservation scenarios have been developed within the frameworks of the IPCC (Intergovernmental Panel on Climate Change) and IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) to explore pathways for reducing human-induced pressures and the drivers of biodiversity loss. Yet, it remained to be determined whether the most ambitious conservation scenarios would be sufficient to halt the decline of common biodiversity in Europe? 

This is the question addressed by a study co-funded by the BioAgora project, one that assesses how conservation scenarios and their impact on multiple drivers of environmental change (including climate change and land-use change) could affect bird and butterfly populations across Europe by 2050.

Assessing the impact of conservation scenarios on common biodiversity

The study, led by the National Research Institute on Agriculture, Food & the Environment (INRAE) (Stanislas Rigal, Sandra Luque, Maxime Lenormand and Léa Tardieu (UMR TETIS) involves 36 authors (affiliated with 38 research entities).  It analyses the effects of climate, land use and land-use intensity on 265 common bird species and 144 common butterfly species using observations from more than 20,000 sites across 26 European countries between 2000 and 2021. These species are modelled so as to understand how their abundance would be shaped by alternative land-use futures based on the IPBES Nature Futures Framework - Nature for Nature (NFN), Nature for Society (NFS) and Nature as Culture (NAC) - combined with the most sustainability-oriented climate and socio-economic pathway, SSP1 (“Green Road”), from the IPCC. These scenarios thus allow to project potential changes in common biodiversity across Europe up to 2050.

What are the study’s findings?

The paper shows that none of the conservation scenarios assessed is sufficient to halt, let alone reverse, the projected decline in the average abundance of common bird and butterfly species. This remains true even under the most biodiversity-friendly scenarios incorporating key EU policies, including the EU’s 2030 Biodiversity Strategy, 2030 Forest Strategy and Farm to Fork Strategy. The decline is particularly pronounced for farmland birds, while grassland butterflies continue to face strong pressures from agricultural intensification and land abandonment. Climate change exacerbates these circumstances, with particularly negative effects on butterflies. Forest species fare relatively better, partly because of expanding forest cover, although intensive forest management continues to increase even under conservation-oriented scenarios. Importantly, the benefits of conservation scenarios are unevenly distributed across Europe, with stronger improvements projected in Western and Northern Europe and more limited positive effects in eastern and southern regions, where agricultural pressures are increasing.

The findings point to a fundamental challenge: current conservation scenarios largely address how land is managed without fully questioning growing societal demands for agricultural and forest production. This creates persistent trade-offs between production and space for biodiversity.

Needs for a new approach to conservation 

The results therefore suggest that current conservation ambitions may not be sufficient to secure the future of Europe's common biodiversity. More ambitious, integrated and transformative pathways are needed to reverse biodiversity decline and secure the future of Europe’s common species.. In other words, a better balance between socio-economic priorities around resource use—which underpin many current restoration frameworks—and targeted biodiversity conservation commitments is needed to achieve more effective conservation outcomes. Taking a broader perspective, this evidence-based vision aligns with BioAgora’s ambition to transform policymaking by grounding decisions in scientific evidence and field-based data through an EU Science Service for Biodiversity (SSBD).

The full study is available here in the form of an open-access preprint, while a corresponding research article was published in the Nature Ecology & Evolution journal.

Based on the press release issued by BioAgora on Eurekalert 

BioAgora is a five-year European collaborative project funded by the Horizon Europe programme, involving 22 partners across 13 european countries. It aims to connect research results on biodiversity to the needs of decision-making in a targeted dialogue between scientists, other knowledge holders and policy actors.

Its main outcome is the development of a fair and functional Science Service for Biodiversity that will orchestrate processes and initiatives at the Science-Policy Interface at the European level.