|Adult male Common Pochard (Alexandra Park, Greater London, 17 February 2008).|
|Adult female Common Pochard (Alexandra Park, Greater London, 7 September 2009).|
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 35 Tufted Ducks and Common Pochards on my patch last month, it is a question worth considering. In this instance statistics don’t tell the full story, as the photos below show - these two lookalike (and potentially related?) birds are not Tufted Duck x Pochard hybrid spawn.
|Aythya hybrid 1 (Alexandra Park, Greater London, 19 December 2010).|
|Aythya hybrid 2 (Alexandra Park, Greater London, 19 December 2010).|
|Adult female Ferruginous Duck (Burgess Park, Greater London, 28 November 2010). Note the uniform plumage.|
In view of the head/bill profile, plumage details and other characters of the two hybrids, my feeling was that they were Common Pochard x Ferruginous Duck hybrids (surely not interbreeding anywhere near London?). Keith Vinicombe has far more experience with hybrid Aythyas than me, so I asked him for his opinion. He replied: “I'd say that the hybrids look like juveniles and that Pochard must have been one of the parents, given the ‘Pochard grey’ shading on the scapulars and flanks plus the extensive black at the tip of the bill. The bottom bird also has a dull red eye, which would also indicate that (a) it is a juvenile male and (b) that one of its parents was a Pochard. (The top one also seems to have a reddish eye too). The black ground colour to the upperparts would suggest Tufted or Ferruginous as the other parent, while I would have said that the reddish brown breast would be indicative of Ferruginous. The lack of any tuft would not favour Tufted as a parent. Overall, I would guess that they are Pochard x Ferruginous, but at the Pochard end of the hybrid spectrum.”
|Tufted Duck x Common Pochard hybrid recalling Lesser Scaup (Alexandra Park, Greater London, March 2010).|
|Firt-winter drake Lesser Scaup (Regent's Park, Greater London, March 2003).|
|First-winter female Lesser Scaup (Caerlaverock WWT, Dumfries and Galloway, 15 February 2006). The tell-tale|
vermiculations are beginning to emerge. Jizz-wise, it is quite distinct in both shape and posture on the water.
|Here is the same first-winter female Lesser Scaup (left), with a lookalike Tufted Duck for comparison. The bill|
pattern and more solidly dark upperpart coloration of the latter are among the clues to its true identity.
- A bird in Berkshire thought probably to be Ferruginous Duck x Pochard
- Another Ferruginous-type wannabe in the same county
- This bird is much more like a Ferruginous
- Another Ferruginous x Pochard hybrid, this time from Switzerland
- … another from Italy …
- … and then video of one in France
- Finally, Nigel Milbourne has a few grotty Aythyas depicted on his Blagdon Lake website