The Dutch butterfly population shrunk by at least 84% between 1890 and 2017, national statistics agency CBS and the Vlinderstichting report.

The new figures are based on an analysis of long-term data resulting from a national measuring programme developed by the two organisations.

Three years ago scientists recorded a growth in some types of butterfly for the first time since monitoring began in the early 1990s, especially among rare species such as the dark green fritillary. However, the latest figures show that their number is declining again.

One of the main causes for the decimation of butterfly populations is intensive agriculture which has done away with the vegetation on which butterflies thrive. The figures show that where natural environments have been restored rare butterflies have returned.

According to this year’s red list for butterflies in the Netherlands, 15 species have disappeared completely while 12 are critically endangered, 10 are endangered, seven vulnerable and three are near threatened. Only 29 species are not under threat at the moment.

However, a number of rare woodland butterfly species (wood white, white admiral, purple emperor, silver-washed fritillary) have profited from global warming and a greater variety in trees over the years, the organisations say.

Read the report (in English)