New Red List 2025: Threat to European butterflies has worsened enormously since 2010

The new European Red List of Butterflies 2025 makes it clear: Europe’s butterflies are under increasing pressure—and many species are close to disappearing. The current assessment shows not only a serious deterioration since 2010, but also how strongly habitat loss, intensive agriculture and climate change are affecting populations.

A continent is losing its butterflies

Europe is home to a total of 501 butterfly species. For the new Red List, 442 species were assessed—those that are native to Europe or have long been established there. The Madeiran large white (Pieris wollastoni) was classified as extinct, leaving 441 extant species for the calculation of threat categories.

How many species are threatened?

Of these 441 species:

• 65 species (14.7%) are threatened, including
  • 6 species (1.4%) Critically Endangered (CR), e.g. Pseudochazara cingovskii (North Macedonia), Coenonympha phryne (Eastern Europe/Southern Siberia) and Polyommatus humedasae (Italy)
  • 35 species (7.9%) Endangered (EN), such as the Sierra Nevada blue (Polyommatus golgus), Canary Islands large white (Pieris cheiranthi), Arctic ringlet (Erebia disa)
  • 24 species (5.4%) Vulnerable (VU), e.g. Essex skipper (Thymelicus lineola), false Apollo (Archon apollinus), Erebia epistygne

In addition, 60 species (13.6%) are considered Near Threatened (NT)—including the small blue (Cupido minimus), the violet copper (Lycaena helle) and the grizzled skipper (Pyrgus malvae).

This means that 28.3% of all European butterflies are now on the brink. Almost one in three species is already threatened or shows clear population declines.

The largest share—around 70% of all species—is considered Least Concern (LC). A further 59 species were not assessed because they were introduced after 1500 or occur only marginally in Europe.

Clear deterioration since 2010

Since the last Red List, the situation for Europe’s butterflies has deteriorated massively:

• The share of threatened species rose from 8.5% to 14.7% (+73%).
• The number of threatened species grew from 37 to 65 (+76%).
• Including the Near Threatened species, the total number of affected species rose from 81 to 125 (+65%).
• Particularly worrying: the number of Endangered and Critically Endangered species has more than doubled from 15 to 41 (+173%).

One improvement in the current assessment: not a single species is still considered Data Deficient (DD). All species could be assessed, reassigned or taxonomically clarified—further strengthening the reliability of the results.

Population trends: More than half of species are declining

Trend data are available for many European butterfly species, and they paint a clear picture:

• More than 50% of species are declining,
• 35% have stable populations,
• only 14% are increasing.

Trend data are missing for around 43%, often because the species are rare, difficult to detect or live in regions where little monitoring takes place. The situation is particularly critical for endemic species, meaning species that occur exclusively in Europe. Of the 148 endemic species still present today:

• 19.6% are threatened
• 21.6% are Near Threatened

This means that more than 40% of all European endemics are considered threatened or close to it—almost twice as many as in 2010 (23.2%).

Regional hotspots of species loss

Threatened butterfly species are not distributed evenly across Europe. Particularly affected areas include:

• Northern Europe: species are losing their cool habitats because of rapid warming.
• The Alps, Carpathians, Ukrainian and Russian steppes: sensitive mountain and wetland habitats are coming under pressure.
• The Sierra Nevada and southern Balkan region: additional pressures arise from the combination of heat, drought and more frequent fires.

These patterns reflect particularly sensitive habitats, biogeographic transition zones and the impacts of climate change—both in the north and in the southern Mediterranean region.

Why Europe’s butterflies are disappearing

The European Red List of Butterflies2025 identifies several key causes. Many act at the same time—and reinforce one another.

1. Habitat loss and degradation (the greatest threat)

The greatest threat comes from the ongoing destruction and degradation of habitats. Agricultural intensification, the conversion of species-rich meadows into arable land or nutrient-rich improved grassland, high nitrogen inputs from fertilizer, the drainage of wetlands as well as overgrazing or the abandonment of traditional land-use practices all lead to the loss of valuable open-country habitats. In many regions, shrubs and forests are also spreading when extensively used areas are abandoned. As a result, habitats become fragmented—leaving small, isolated habitat islands where local populations can quickly die out.

Example species: Large blue (Phengaris arion), violet copper, Danube clouded yellow (Colias myrmidone) and Melitaea aetherie (a fritillary)

2. Nitrogen inputs

Nitrogen from agriculture and traffic accelerates plant growth and destroys nutrient-poor, open habitats that many butterfly species depend on. It changes the microclimate and displaces the food plants of caterpillars.

Example species: Wall brown (Lasiommata megera), which has declined sharply in Western Europe

3. Pesticides

Pesticides harm both adult butterflies and their caterpillars—even when they live far outside intensively farmed areas. Many active substances spread for kilometres by wind or water and can reach protected areas. Long-lived neonicotinoids are particularly problematic, and their risks to butterflies have so far been underestimated.

Example species: Essex skipper, common blue butterfly (Polyommatus icarus), which is widespread but declining in many regions

4. Intensification and abandonment of traditional agriculture

While productive land loses habitats through intensification, less productive areas are increasingly being abandoned. As a result, shrubs and forests grow into formerly open meadows—a process that threatens many species of cultural landscapes.

Example species: Violet copper, large blue, Erebia epistygne (a ringlet)

5. Changes in forests

Forest area in Europe has been increasing for years—through afforestation, lack of management and climate change. Some forest species benefit from this, but many butterflies depend on open, sunlit woodland areas, forest edges or clearings. When these structures are absent, the species that rely on them disappear too.

Example species: Erebia ottomana (a ringlet), woodland ringlet (Erebia medusa), scarce heath (Coenonympha hero)

6. Climate change

Climate change has now become a powerful additional stress factor. Already, 52% of threatened species in Europe are directly affected.

• Warming and habitat shifts:
  Species move northward or to higher elevations, but lose habitat in the process. Alpine and near-tundra species are particularly affected.
  Examples: Arctic blue (Agriades aquilo), Boloria freija (a fritillary), Erebia disa (a ringlet), Oeneis bore (an arctic)
• Mediterranean droughts and fires:
  Increasingly frequent extreme events are hitting island species especially hard, because their habitats are very small and isolated.
  Examples: Hipparchia christenseni (Karpathos – Greek island), H. tamadabae (Gran Canaria), H. tilosi (La Palma), Canary brimstone Gonepteryx cleobule (Canary Islands)
• Decline of alpine endemics in southern Spain:
  Species that live only on a few mountain summits and have few opportunities to move elsewhere are especially sensitive. Through warming, they are losing their entire climatic range.
  Examples: Agriades zullichi (a blue), Sierra Nevada blue, Andalusian anomalous blue (Polyommatus violetae)

What needs to happen now

The results show clearly: protected areas alone are not enough. Many valuable habitats are in poor condition. Experts recommend:

• large-scale, connected landscapes instead of isolated reserves,
• adapted mowing and grazing,
• active habitat management in forests, heathlands and wetlands,
• expansion of monitoring programmes such as the eBMS (European Butterfly Monitoring Scheme),
• consistent implementation of the EU Nature Restoration Law by 2030.

Butterflies as an early warning system

Butterflies are extremely sensitive to environmental change and are therefore a reliable indicator of the state of our ecosystems. The European Red List 2025 is not just an inventory, but a warning: when even widespread species are declining, the stability of our habitats is at risk.

Who is behind the European Red List?

The European Red List of Butterflies is published by the International Union for Conservation of Nature (IUCN). The new edition is based on a large-scale project funded by the European Commission and scientifically coordinated by Butterfly Conservation Europe and an international team of leading lepidopterists. All European butterfly species are assessed according to the IUCN criteria. The list serves authorities, NGOs and researchers as a central basis for planning conservation measures, measuring progress and supporting legal frameworks such as the EU Biodiversity Strategy or the Nature Restoration Law. In this way, the Red List shows not only the status of one species group, but also the ecological health of numerous habitats in Europe.

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Source

• European Commission, Directorate-General for Environment, Van Swaay, C., Warren, M., Ellis, S., Clay, J., Bellotto, V., Allen, D. J., & Trottet, A. (2025). European red list of butterflies. Publications Office of the European Union. https://doi.org/10.2779/935927