NDFF Amphibian monitoring program 2011

The amphibian monitoring program primarily focuses on areas where key species occur. However, the development of common species in these areas can also provide important additional information. We therefore follow all amphibians in areas where key species live, including common varieties. Data about all species is collected during field visits. The monitoring program supplies information about the current state of and changes to amphibian populations in the Netherlands in collaboration with Statistics Netherlands (CBS). Positive observations without zeros. NDFF protocol 1.202 https://www.ndff.nl/overdendff/validatie/protocollen/1-202-monitoring-van-amfibieen-in-nederland-2011/