According to the recent report of the European Environment Agency (EEA), European grassland butterflies have declined dramatically by almost 50% over two decades. This study highlights an alarming trend for butterflies and complements the assessment by the European Red List of Butterflies conducted by IUCN.
17 grassland butterflies have dramatically declined between 1990 and 2011, according to the EEA report. The status of many other European butterflies is also of concern, as confirmed by the European Red List.
The European Red List of Butterflies, funded by the European Commission, has revealed that 9% of all European butterflies are threatened with extinction at the pan-European level (7% at the EU 27 level). Overall, more than 30% of the 435 species assessed have a declining population. The Lulworth Skipper (Thymelicus acteon) – one of the grassland species declining most rapidly according to the EEA report – is listed by IUCN as Near Threatened in Europe, which means that the species may be considered threatened with regional extinction in the near future, although it does not currently qualify for the threatened status.
Butterflies are a hugely important group of insects as they provide important ecological services such as pollination of wild flowers and act as a food source for birds, reptiles and other species. They are also excellent bio-indicators of habitat quality for sites, including within the Natura 2000 network.
Butterflies in general, and grassland butterflies in particular, are threatened by a number of different factors, including the intensification of agriculture. The conversion of grasslands to crop fields, the drainage of wetlands and various grazing pressures are examples of such threat. The abandonment of land and lack of grassland management on marginal areas also have an impact on butterflies’ habitats, as they reduce the availability of suitable spaces for the species to inhabit. Other threats include climate change, poor woodland management (i.e. lack of open areas and clearings), habitat fragmentation, pesticides and herbicide use and invasive alien species.
The alarming results show that Europe is not on course to halt the decline of biodiversity. As we are approaching the half way point of 2020 – when the biodiversity targets set by the EU expire, efforts need to be intensified. Ensuring adequate protection, management and restoration of key habitats and their surrounding areas is crucial for improving butterfly populations. The recent reform of the EU Common Agricultural Policy offers an opportunity to allocate funding for more sustainable farming practices in High Nature Value Farmland, which would contribute to reversing the current trends and meeting the EU 2020 Biodiversity Targets.