I like the pose, the rim lighting, the way the light seems to be shining through the beak - and the reflection of the other heron's neck in the water. The image appears to have an overall yellow-green color cast which I'm not that fond of.
I have to agree with Steve on the color cast which I find annoying as well as the shadow of the other Heron, my eye seems to be attracted to that part of the image, thank you for sharing.