Jack Douglas said:
Mallards are everywhere but for some reason they don't frequent my little pond much and then they are never tame enough to get near. However, lately a pair of Mamas have been very friendly so as I watched for other subjects I finally gave in, back up and snapped this @ ISO 10 000. I can honestly say I'm very pleased with the high ISO capability of the 1DX2.
Jack
great photo.
Compare the bill with your previous post of a possible mallard which is yellow.
Possibilities:
a) male mallard moulting (eclipse) plumage
b) Mexican mallard. Do they reach Canada?
c) Mottled duck
d) American Black duck
e) interbreeding with other species
The Cornell app opts for mallard and does not offer other species as options. Strange as an experienced birder friend of mine is adamant that your original photo is not of a mallard, either male or female.
Just shows how carefully you have to look at even common species. Do have any other shots of original duck perhaps showing wing flash?
Attached is a poor quality photo of a drake mallard enduring contortions to preen a hard to reach feather.
Also compare your original photo to sitting on a fence posted by dpc on page 530 of this thread. It has a yellow bill and taken in Canada.