Many bats thrive where there are thin forests of noble broadleaf trees and sources of energy-rich water to produce large numbers of insects on which they feed. Many species also need hollow oaks for surviving the winter.
There are at least 14 species of bat in Sweden, of which nine occur in the Royal National City Park. Two of these, the whiskered bat and Natterer’s bat, are threatened species, which means that in the long term they risk extinction in Sweden. It is not easy to distinguish between the different species of bat, and if you want to learn about these nocturnal animals you might want to join one of the bat-watches often organised in the park.
The whiskered bat, Myotis Mystacinus, whose numbers have greatly declined in the whole country in recent decades, is still fairly common in the park.