The number of 17 butterfly species distributed in Europe has decreased by 39 percent since 1990, TASS reported. The data are from the European Organization for the Conservation of Butterflies, based in the Netherlands.
Scientists have studied butterfly populations in the Netherlands and Britain. In the Netherlands, they have decreased by 50 percent since 1990. The number of 25 species has decreased, but increased to 16, and the average number of nine more species has not decreased. In Britain, the butterfly population has shrunk by 50 percent since 1976. And there are positive trends. About 30% of the species expand their range. The number of many of them is also growing.
Reasons for declining butterfly populations in many European countries are shrinking habitats due to agricultural development, air and soil pollution with chemicals, and climate change. However, the latter factor also has a positive effect because it allows thermophilic species to expand their range to the north. However, those accustomed to colder climates are either dying out or being forced to settle at higher altitudes.
To protect endangered butterfly species, scientists propose to monitor the condition of their habitats, to use more environmentally friendly farming methods and financial assistance to farmers who engage with them.
The results of the study are published in the Journal of the American National Academy of Sciences.