Clouded apollo is a butterfly species which prefers grazed bright forests. If the edge of a forest is grazed by animals, it is kept open without thorny bushes and branches of the trees start in the height where animals could not reach them anymore.
When there is no pasture in a countryside anymore, forest edges will change too. The forest edge becomes overgrown – if someone wants to enter such forest, he/she must fight his/her way through dense and thorny bushes.
Excluding pasture means that the countryside is deprived of the organic connection between the pastureland and forest. And also, of clouded apollo since it needs such places. It used to live in Devín a few decades ago. But it doesn’t anymore – just due to the fact that there are no more grazed edges of the forests and bright, grazed forests.