NDFF Butterfly and dragonfly monitoring program

The aim of the NEM butterfly and dragonfly monitoring program is to collect up-to-date information about changes to the butterfly and dragonfly population in the Netherlands. Standardized survey methods and locations are used. Routes are marked across the country so that observers can all use the same counting method. Records are kept every week during the season on what butterfly and dragonfly species occur in a location and how many. The people in the field provide basic information about their routes. The results are used to find changes and causes of these changes in the populations of butterflies and dragonflies. Dataset available via https://www.ndff.nl/english / [e-mail] Positive observations without zeros. NDFF protocol 3.202 https://www.ndff.nl/overdendff/validatie/protocollen/3-202-landelijk-meetnet-vlinders-en-libellen-2011/