Recent climate changes are most likely the major determining factor for the increasing importance of Central Europe for wintering waterbirds, given that most of the region is located on the edge of these species' wintering ranges. A few recent large-scale studies have demonstrated changes in species distribution at the flyway level, but detailed studies at the site level are still scarce.
Using mid-January wintering waterbird counts from 532 sites taken over a 48-year period (1966-2013), we have assessed the role of 'cold-weather refuges', i.e. sites where the selective pressures of winter harshness are reduced (e.g. sites with ample sources of running water, urban areas, warmer sites, sites with a relatively higher proportion of wetlands), and a site's protection status on species richness, total numbers and trends at the site level.