So far, three versions of the PECBMS European species classification have been produced and used. The first set of European indicators was based on European trends of 47 common bird species, classified according to the national coordinators’ expertise of monitoring schemes and other experts who met at the PECBMS workshop in Prague in 2002. For the second set of European indicators based on an enlarged species sample, we improved the classification. It was based on a publication by Tucker & Evans (1997), describing habitats and their importance for birds in Europe. Since 2007, when we produced the third set of European indices and indicators, data on more than 100 species are used, and the species classification is based on assessments within bio-geographical regions in Europe.
See more in Methods, chapter 3, Box Species selection, and classification.