European grassland butterfly abundance has declined by 30% since 1990

Due to their high numbers of species and their wide range of ecological requirements, butterflies, like birds and vascular plants, are good expressions of the level of biodiversity (that is, the variety of life forms) in our landscapes. Their generally low dispersal capacity, their short life cycle and a high sensitivity and responsiveness to climate conditions also make butterflies good bioindicators of environmental change. In addition, butterflies are emblematic, well known and easy to identify in the field. The European Grassland Butterfly Indicator represents one of the EU biodiversity indicators of the European Environment Agency (EEA). Data for seventeen grassland butterfly species have been used to assess abundance trends between 1990 and 2013. Of those seventeen species, "ten have declined in the EU, three have remained stable and three increased. For one species the trend is uncertain". At the European scale, grassland butterfly abundance has declined by 30% since 1990.

Source: LIST, 28 August 2015
http://www.list.lu/en/news/biodiversity-european-grassland-butterfly-in…