The smew Mergellus albellus observed
16 at Mlýnsky pond 48.7853769N, 16.8193242E
20 Hlohovec 48.7813617N, 16.7807864E
7 Nesyt 48.7773458N, 16.7128942E
Czech republic
Cca 10 fully coloured males altogether.
It is unusual for this locality to see so many individuals.