I took this photo today down at the New Jersey shore. Usually most ducks take off when I approach. These ducks came looking for me. Probably used to being fed. I went with a square crop. C&C appreciated.
The colors are good and the front one is nice and sharp Steve. To get both birds sharp (and assuming your focus point is on the first duck) you may need to close the aperture down to increase the Depth of Field.
I like this image for the creative composition, beautiful colour and exposure and the lovely background. Indeed the first duck is nice and sharp. I think it would also work well to use a larger aperture and/or get closer to blur the duck behind more (Kind of like Mike's glass shots), or a smaller aperture as Frank suggested to capture both ducks with greater DOF.
This is the kind of scene that presents a whole lot of difficulties particularly because there is but a split second before the scene changes. In the circumstances this is an excellent shot. You might be able to get away with a slight sharpening/contrast adjustment to the further bird to bring both more into line.
I like the composition and the picture has great color. I agree with the others about trying to sharpen or blur the second duck. I sometimes have the same problem when taking pictures.