Towards a new generation of breeding bird Atlases: annual Atlases based on site-occupancy models

Site-occupancy models which take into account detection probability of species have promising applications for Atlas work. These models enable to estimate the ‘true’ state of occupancy in sites even if sites differ in observation effort. Data collected with different field methods and opportunistic data collected without standardized field methods may be used together to derive reliable inferences on species distribution, colonisation and extinction. This may lead to a new generation of atlases with annual distribution maps on the internet. We emphasize the remarkable perspectives of these models and discuss some problems that need to be solved.