Presumed Tufted Duck x Pochard
In most instances Aythya hybrids are evidently of mixed parentage but can sometimes resemble a third species. Some hybrids between Tufted Duck and Pochard can have a superficial resemblance to Lesser Scaup, others to Redhead (while Pochard x Ferruginous Duck is deemed to produce even more Redhead-like offspring). The head colour of the presumed hybrid Tufted Duck x Pochard in the images below contained both purplish-black and chestnut components. The prominence of each was very much dependent upon the strength and angle of the incident light. This would be partly a result of colour 'sheens', which are produced by optical interference rather than pigment and are very dependent upon the angle of the incident light. The head shape and indications of a rudimentary 'tuft' also varied, depending upon posture, wind conditions and whether or not the head was 'sleeked' by recent diving. Consequent upon these conditions, its overall appearance could shift markedly from a more Tufted-like appearance to a more Pochard-like appearance and it could briefly and superficially suggest a drake Redhead.
Here the head appears blackish with slight purple sheen; crown feathers tousled. Quite Tufted-like but with dark grey upperparts.
Head appearing blackish with dull purple gloss; crown contour looking smooth but overall head-shape again suggests Tufted Duck.
Head with strong purplish gloss; crown feathers looking smooth. Evidently of 'mixed' parentage but with less of a Tufted-like appearance overall..
Head feathers appearing admixed chestnut and purple-black. In these light
conditions overall resemblance closer
to Pochard than Tufted Duck but head too flat-topped and bill pattern closer to Tufted.
Head with strong chestnut hue; crown feathers appearing smooth. In this image
there is a resemblance to a drake Redhead
but flanks too pale and extended observation soon confirms the highly varying appearance, especially of the head colour.
Head feathers with chestnut 'highlights' to a purplish-black ground colour; rudiments of tuft at rear of crown.
© A. R. Dean
Aythya hybrid, Warks, November 2015