Continuity mistake: When the big dog points his gun towards the hole in the log, the length of the log changes between shots.
Continuity mistake: After the ducks have flown away when the whistle has blown, there is a shot of the hunters in their boat and you can see the big dog is pointing his gun to the left. When the camera pans in on the hunters in the next shot, the big dog is now pointing his gun in front of him.
Continuity mistake: When Lucky Ducky peels off his egg suit, there are pieces of broken egg on the side of the boat. When the two hunters put their guns in the water in the next shot, the pieces of egg have gone.