Hybrid Aythya duck, Green Valley STP, Pima County

This atypical appearing male Aythya duck was found by Molly Pollock and photograped by Mark Stevenson at the Green Valley STP on 23 April 2010.

In good light the head had a green gloss, visible in one of the photos attached, suggestive of scaup. The top side of the body is gray due to fine white vermiculations, finer than seen in scaup. It has a bit of a pointed crest, suggestive of Tufted Duck. The white band at the base of the bill and the white "spur" on the front of the flank seen in Ring-necked Duck are absent but the bill has a black tip and subterminal white band, as in Ring-necked Duck.  It associated closely with a female Lesser Scaup. 

The dark back of this bird suggests it has one black-backed parent (either Tufted or Ring-necked) and one gray-backed parent (either scaup).   Looking at hybrid combinations in Mullarney et al, it doesn't match any of the depictions of Tufted Duck hybrids, especially the bill.  The bill is more suggestive of a Ring-necked Duck parent.  Despite appearing somewhat tufted, it seems most likely this is a Ring-necked Duck X Lesser Scaup hybrid.  Both these species have peaked crowns that could appear as a small tuft and despite illustrations to the contrary in field guides, Lesser Scaup can have a green gloss on the head.  There is one Arizona record of Tufted Duck (a bird that returned to Mesa for more than one winter).

23 April 2010, photos by Mark Stevenson

All photos are copyrighted© by photographer