Table S2: Results of general linear mixed models showing (GLMM) the influence of different count methods (Ground vs Aircraft) performed in different ice cover presence (1—ice cover present, 0—no ice cover) in relation to different groups of species (Group 1: Cygnus olor, C. Cygnus, Aythya marila, A. fuligula, Mergellus albellus, Mergus merganser, Bucephala clangula; Group 2: Anas platyrhynchos, Mareca penelope, Aythya ferina, Fulica atra, Podiceps cristatus; Group 3: Mareca strepera, Anas crecca, Spatula clypeata, Anas acuta, Spatula querquedula). Count dates and species were treated as random effects (r) and these are given as a variance with standard error