Nice shading on his torso and face. I also think you did a lovely job with the grass. The wings are excellent, I like how you drew the end feathers darker, it felt more hawk like that way, and you did a good job with the texture for it too. The water is a nice color, and the whit parts are well placed.

One thing to consider when doing water and grass is that the grass never just goes into the water, which you have here. Either there is a bank, where you can see rocks and stuff going from the grassy top down to the water and dirt and earth compacted together or you see the grass fade out and a sandy beach then leads down tot he water. The beach can be just a few inches wide... so I guess it wouldn't really be a beach... but still, I think you get the idea.

As for reflections, the reflection of his shirt is well done, but there is no reflection of the rest of him. i like the idea behind the reflection of the sun in the water also, but a suggestion is that you draw blue in with it. Not mixed... but little lines of blue interacting with the reflecting lines, so you will have the reflection, but it will be distorted by the ripples of the water shown as waving blue lines intermingling. The only exception is when you are drawing a perfectly calm and undisturbed water, which can't be the case in this picture because by his being in it, he has disturbed the calm.

Love the light outline on teh branches and I really like the dark mossy stuff you added, it is a nice touch, feels more wild that way.

Overall, a nice job, you are getting better with your backgrounds, keep it up.