Ok you asked for it..
The first shot has the focus off somewhere between the duck and the deer (in fact a little closer to the duck) but as the duck has its head hidden and the focus is off on the deer the picture is really compromised.
Picture two is better focus wise but is still a little soft, also the framing is such that you have all the deer in the centre of the frame and shot from side on, it is usually much better to have some free space in front of any animal. Also there is a much better picture hiding in this shot, if you had done just a head shot of the deer drinking, again leaving some free space in front it would be a very strong shot. Obviously it would require a longer lens or moving closer to the subject, both of which may have been impossible for you.
Picture three is much better composition wise for the deer and shows it not to be flat by the angle it has been shot at, again I would have lost the duck completely and reframed just on the deer leaving that essential small amount of free space in front.
Picture four has the duck with its feet completely cropped out of frame and the focus definitely has to be spot on the eye. I tighter crop just on the head would have been a much better composition or a lower down shot including all of the subject.
Overall you have the basics but are missing some essentials, the framing and focus must be spot on, especially with animals, the latter I feel could be improved with a little more time spent during post processing. Take a look at the recent threads posted by Marcel where his squirrel shot has been transformed from an average photo to a superb shot by a good crop and some skilful processing and sharpening. The goods are there, they just need to be brought out to show them at their best.
Don't take any of the above personally, I have been quite brutal but I can assure you we have all started out with shots with all the same faults as you have shown here. Practice, practice, practice and don't become downhearted. Its a skill that needs to be learned by the majority of us, there are not many of us that have it naturally unfortunately