I was looking at your fencing in the video. I think
the answer might be there, and in your order of operations.
Would it make sense to put the ducks in the
tractor in the enclosed space of the grazed paddock, but near as possible to the end nearest the next paddock, then shift the surrounding
fence to enclose the new paddock and the tractor, still on a small piece of the grazed paddock?
Even if you were to herd the ducks from the tractor to the newly fenced fresh paddock in the manner you did in the video (assuming non-contiguous paddocks), it would mean moving the ducks directly into containment (or never having them leave containment), whereas in the video, any escapees of the move into the tractor were free to run around the tractor, or anywhere else.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein