Authors: Voříšek, Petr; Keller, Verena;Herrando, Sergi;

The first European Breeding Bird Atlas (EBBA1) was published in 1997 and the second one (EBBA2) in 2020. Both atlases are based on fieldwork of skilled volunteers and professionals and document the breeding occurrence and abundance for the whole of the European continent in a standardised 50-km grid. They provide information on the status and abundance of each species in each grid square in categories of breeding codes and abundance. In addition, EBBA2 provides modelled maps of the probability of occurrence at a resolution of 10x10 km. EBBA1 and EBBA2 allow to compare the distribution of species and assess changes over the last 30 years. 35% of all native species have increased the area where they breed since the 1980s, 25% have contracted their breeding range and the rest did not show a change or the trend is unknown. While the breeding ranges of species moved on average to the north, there are range shifts in other directions too. The observed range shifts are not always consistent with results from predictive models using information on climate and land use. Thus, real data on species distribution changes is needed as a basis for research and conservation and particularly to validate models.