Key stone

The black woodpecker eventually abandons its nest, but other birds move in instead. These are, for example, the Tengmalm's owl, jack daw and stock dove, as well as some smaller mammals: squirrel, marten and bats. None of these species make their own holes. Trees with old black woodpecker's holes, are therefore essential for these species. The black woodpecker is a so-called "key stone species", important for the existance of other species.