Mallards may be common, but they are very handsome birds, and great fun to practice on.
Excellent full downstroke wing position, nice display of tucked feet.
The rear of the bird seems sharper than the front, and the head and eye are fairly soft on my monitor.
Just a bit hot on the whites by the feet. The background is complimentary. I might consider moving the bird just a smidge more to the left in the frame.
You might consider a smaller sig line, or at least more transparent.
With fast moving ducks like Mallards, I might recommend trying to stay above 1/1000 sec. or faster for flight shots. You had plenty of room to increase your ISO.
thank you for your input. In fact I was occupied shooting another bird when I saw the mallard. No time to make any adjustment! I can sharper a little bit more and have some space to move it more to the left.
The pattern on the wing reminds me a flag.
The bird seems small on the frame, may be is the border around it. It would have been great to see more details on the blacks but I know it's hard to make adjustments as they fly. Great image any ways.