Hibernating bats in fortifications of the New Dutch Waterline 1980-2020: The ups and downs of a dynamic co-existence of natural and cultural heritage

Abstract: Man-made structures are quite important for bats in a country like the Netherlands with hardly any natural rocks or caves. This paper describes the use that hibernating bats make of buildings that were originally put up for military purposes: the fortifications of the New Dutch Waterline (NDW). Over the past seventy years, when their military usage ceased, many of these buildings grew into important sites for bats, especially for hibernation. However, since the 1990s these buildings have come to be considered as an important cultural heritage and managed as such. Can these two important values co-exist? Part I of this paper describes the use of fortifications by hibernating bats and part II describes the developments in the numbers of hibernating bats as a result of changing use and management.