This guide is based on wikipedia's list of birds of Germany with accidentals removed to keep the guide under 500 entries.
The Tufted Duck (Aythya fuligula) is a medium-sized diving duck with a population of close to one million birds.
The Greater Scaup (Aythya marila), just Scaup in Europe, or colloquially "Bluebill" in North America for its bright blue bill, is a mid-sized diving duck though it is larger than the closely related Lesser Scaup. It is a circumpolar species, which means that its range circles one of Earth's poles. It spends the summer months breeding in Alaska, northern Canada, Siberia, ...more ↓
The Ferruginous Duck, also Ferruginous Pochard (Aythya nyroca) is a medium-sized diving duck from Eurasia. The species is known colloquially by birders as "Fudge Duck".