Try for the head. Practice on those head shots, and start thinking about how much lead certain species need. Ex: Mallards need more lead then teal, while teal you really need to follow because they have a tendancy to dash from one point to another.

Another tip... Dont be fooled by a teals and wood ducks maneuverability... Mallards rank AMONG, not sure if they are, but rank among the fastest.

I just gotta hunt