Results of the winter waterbird census in Slovakia in 2019–2022

A total of 75 (59–69 annually) waterbird species with 129 541–166 543 ( =146 567) individuals were recorded during the January censuses in 2019–2022 in Slovakia. There were found no significant differences in species richness between the years. The most abundant species were Anas platyrhynchos (44.5–53.9% of all registered birds), Anser albifrons (6.8–17.7%) and Aythya fuligula (8.8–10.8%). A. platyrhynchos and A. fuligula were also the species with the lowest interannual variability in the number of individuals recorded. On the other hand, Calidris alpina, C. minuta, Cygnus columbianus, Hydrocoloeus minutus and Numenius arquata were registered only in one year, and C. minuta and C. columbianus were recorded for the first time in Slovakia in January. The overall wintering waterbird assemblage can be considered stable in terms of bird numbers in 2019–2022. However, several species (Aix galericulata, A. sponsa, Alopochen aegyptiaca, Mareca penelope and M. strepera) showed an increase in wintering individuals.