Scientists do not believe their own eyes. A total of 42 percent of Czech butterfly species were counted on a small grazing area. Thanks to wild horses
The results of a census of butterflies from a wild horse pasture in the former Milovice military training area outside Prague have taken scientists’ breath away. In two years, the hoofed mammals managed to create a site with a high degree of species diversity, referred to as a “hotspot”. An analysis of the butterfly monitoring results was completed by experts in recent days.
“In 2016, we recorded 59 species of diurnal butterflies in the pasture (minus the Zygaeninae subfamily), representing an incredible 42 percent of the species found throughout the Czech Republic. Biological data thus clearly show that the area is far from being just a piece of conventional grazing land; rather, it is an extraordinary site that is fully comparable, with its number of diurnal butterfly species, to major steppe reserves,” said Miloslav Jirku from the Biological Centre of the Academy of Sciences of the Czech Republic.
“Diurnal butterflies are one of the most vulnerable groups of animals. This fact is supported by the sufficient degree of exploration – they are a popular subject among experts and their distribution in the Czech Republic has been thoroughly analysed. The main causes of their decline are changes in landscape management; where areas used extensively disappear, European landscapes are either abandoned or exploited intensely,” said Frantisek Pelc, director of the Agency for Nature Conservation and Landscape Protection of the Czech Republic.
It should be noted that the Milovice pasture land covers a mere 40 hectares. In total, the butterflies found in the grazing area include eight species protected by law and five species kept on the country’s red list of endangered species of which one is severely endangered and one is critically endangered.
“Denoting the Milovice pasture as a hotspot would be no exaggeration. One should note in this regard that this is an area that had been degraded for a quarter of a century, causing the loss of its biodiversity. Just two years ago, it was a single large stand of aggressive bushgrass,” commented Jirku.
It is encouraging to see how quickly the species of butterflies settled in a pasture land that until recently was unattractive to most of them. This is due to the extensive volume of nectar available and the wide range of habitats created through the activity of large hoofed mammals.
In the Czech Republic, 161 species of diurnal butterflies are considered as native when not including the Zygaena genus. Of these, 19 species, i.e., 12 per cent, have become extinct in less than the past one-hundred years. As such, 142 species now survive in the country, of which more than one half are endangered species. For some of them, such as the mountain alcon blue, the process of local extinction continues.
“Another butterfly-rich site where wild horses will help manage the landscape is going to be Podyji National Park on the Czech-Austrian border. Two smaller herds are expected to arrive there this spring,” added Dalibor Dostal, director of the conservation organization European Wildlife.
