I don’t know what the level of incidence of hybridisation is between different Aythya species, but having found two hybrids in a small mixed flock of about 75 Tufted Ducks and 35 Common Pochards today, it is a question worth considering. While we were driving south on E45 the flock was noted in Tåning Sø which is the small part of Skanderborg Lake situated west of the highway and on our return later in the afternoon I made a brief stop to scan the flock.
The first hybrid found was male Ferruginous Duck x Common Porchard (Aythya nyroca x Aythya ferina) and the other was a male Tufted Duck x Common Pochard (Aythya fuligula x Aythya ferina). The latter is a rather common hybrid in Denmark, but if accepted by the Danish Rarities Committee the former hybrid will constitute only the third record of this species combination from Jutland.
Ferruginous Duck x Common Porchard (Aythya nyroca x Aythya ferina)
Tufted Duck x Common Pochard (Aythya fuligula x Aythya ferina)