This demonstrates the first step in starting a goosedog. Cord, of course, already works ducks and is fully trained on herding stuff. But he is scared of "messing stuff up" and goosedog work is all about that (the dog needs to push the geese past the flight zone - literally). The idea here is to teach him that when things get messy it's not only okay, but exactly what I want, when he hears the particular tone I use to get the dog to push hard.
http://video.google.com/videoplay?docid=-705191198831351864&hl=en