Get a duck with good eyes. Near sighted ducks sometimes fail to recognize that they are on the old gauges and will go flogging into the nearest hill. Very near sighted ducks will not realize that they have been thrown out and will descend to the ground in a sitting position. This is a most difficult maneuver to follow in an airplane. Choose your duck carefully, it is easy to confuse ducks with geese.
Many large birds look alike.
While they are very competent instrument flyers, geese seldom want to go in the same direction that you do.