Lutra Special 65 (1)- Preface

The winter of 2021 was a special anniversary for bat counts in hibernacula in the Netherlands. It was 40 years after a first overview (in 1980) of the counts in the Netherlands and (almost) 25 years after the start of the National Ecological Monitoring Scheme (NEM) of bat hibernacula, but it was also the winter in which the counts were cancelled across the whole of the Netherlands and Flanders, due to the COVID-19 pandemic This special issue starts off with a historical review of bat counts: Eighty years of hibernation surveys: from banding to monitoring and protection (Glas), which offers a clear view of the past. An introduction to the recent counting period is given by La Haye & van der Meij, who provide an overview of censuses in the Netherlands between 1986 and 2020, outlining how the counts of the various hibernating bat species have developed over the past 35 years. This Lutra special on hibernating bats in the Netherlands and Flanders continues with four regionally-focused articles about the marl quarries in Limburg and Flanders (Weinreich & Verheggen and Palmans, respectively ), the New Dutch Waterline (Buys et al.) and the Dutch coast (Mostert et al.), all regions with their own specific characteristics, where counts have been carried out for decades......