European butterflies under increasing threat from habitat loss and climate change

One species, the Madeiran Large White, Pieris wollastoni, a species that was restricted to the island of Madeira (Portugal), is now officially classified as extinct. It has not been reported since 1986, despite detailed searches. The study also found that over one quarter (28.3 percent, 125 species) are now threatened or close to being so (Near Threatened) in Europe as a whole, and almost one-third (30.9 precent) in the EU27. The situation is even worse when it comes to endemic species for which Europe has a unique responsibility, with over 40 percent of Europe’s endemic butterflies as now threatened or close to being so.

The biggest threats to butterflies in Europe now and in the past are habitat loss and degradation. These have been caused by agricultural intensification, wetland drainage, land abandonment, and overgrazing from livestock. As a result of these changes, many species are now suffering from the consequences of habitat fragmentation, which greatly increase the chances of local extinction.

However, a major new threat has severely affected European butterflies in the last decade: the warming climate. The new assessment found that 52 percent (34) of all threatened species in Europe are threatened by climate change, and this number is expected to grow in coming years. Although the warming climate has allowed some widespread species to spread north, it is having a devastating effect on certain species in both the far north and far south of Europe, as well as in the high mountains. Species that live solely on mountain tops are especially threatened as they need to move uphill as their habitats get warmer, but in doing so run out of space to breed. In the mountain ranges of southern Spain, for example, the Critically Endangered Nevada Grayling, Pseudochazara williamsi, and the Endangered Zullich’s Blue, Agriades zullichi, Sierra Nevada Blue, Polyommatus golgus, and Andalusian Anomalous Blue, Polyommatus violetae, are all European endemics severely threatened by the changing climate.

In the northern alpine and boreal zones of Scandinavia, warmer and drier conditions are allowing scrubs to spread and encroach on sensitive bog and tundra habitats. Eight species are now classed as Endangered as a result, many appearing on the Red List for the first time. For example, the Arctic Blue, Agriades aquilo, Freyja’s Fritillary, Boloria freija, Arctic Grayling, Oeneis bore, and Arctic Ringlet, Erebia disa. In the Mediterranean region, species are increasingly threatened by extreme drought and wildfires. This is threatening several endemic species that are confined to islands, such as the Critically Endangered Karpathos Grayling, Hipparchia christenseni (on Karpathos), as well as the Endangered Canary Brimstone, Gonepteryx cleobule (Tenerife, La Gomera, La Palma), and La Palma Grayling, Hipparchia tilosi (La Palma).

Other growing threats that require further research include nitrogen deposition and new pesticides, such as neonicotinoids, which persist in the environment. Martin Warren, one of the lead authors of the report: “European butterflies are threatened like never before, echoing the mounting crisis facing wildlife. Urgent action is now needed to save a large number of species from extinction. Many of them are threatened from habitat changes due to the warming climate, which will be hard to stop, but by ensuring their habitats are managed as well as possible and populations are large and robust, they stand a chance. Others can be saved from extinction by preventing wildfires which can obliterate habitats for years.”

Sam Ellis, another lead author: “The new study paints a bleak picture for European butterflies. I and others in Butterfly Conservation Europe will be working to take all necessary measures to save as many threatened species as we can. We are already starting targeted surveys to map exactly where some of the most threatened species occur, so that conservation measures can be planned and implemented. For example, the Nevada Grayling and Sardinian Blue, Pseudophilotes barbagiae. We desperately need more resources to carry out surveys, conduct research on how to mitigate changes, and to take conservation action to improve the condition of the habitats on which butterflies depend.”

Chris van Swaay, who led most of the analysis: “We now have much higher quality data than in previous assessments thanks to the many butterfly observations recorded by Europe’s butterfly enthusiasts and to the European Butterfly Monitoring Scheme, which gathers and analyses monitoring data from across most European countries. The new Red List is thus based on robust data on the status and trends of European butterflies.”

More information

• The report: European Red List of Butterflies (PDF: 3,6 MB).

Text: Martin Warren, Sam Ellis and Chris van Swaay, Butterfly Conservation Europe
Images: Kars Veling (leadphoto: Canary Brimstone); Chris van Swaay; Albert Vliegenthart; Michiel Wallis de Vries