Highball calling tutorials:
Highball calling tutorial: part 1
(mp3) | Highball calling tutorial: part 2
Waterfowl hunters should use the highball selectively—at certain times and in certain places. When a front has passed and new birds are moving into the area, a series of highballs can mesmerize migratory flocks looking for a safe place to rest. When ducks are returning from feeding to a resting area, a well-timed highball might convince them to short-stop at your spread. If ducks are trading over a marsh or lake at long distance, you may need to call a lot to be heard a little.
In all these cases, when one or more ducks show signs of listening—slowing their wingbeats and perhaps sliding out to the side of the flock—pour the calling on. If a single breaks off and cups its wings, others will probably do likewise.
Conversely, blowing a highball is not the best approach on warm, still, overcast days; in the close confines of flooded timber or small marshes; or for “local ducks” that have been educated by heavy hunting pressure.