Do you mean the manual from 2001 or is there a more recent one? I'm still skeptical about it. It seems to me that they use hand-rearing as a way to neglect the problem of badly-designed cages, at the cost of natural behaviors essential if you'd ever want to reintroduce such birds.The AZA care guide says that no detrimental effects have been observed from hand-rearing, and in fact, it decreases the risk of harmful, nervous, or clumsy behaviors such as running into mesh or chipping parts of the beak off. It also allows the toucans to be trained at a young age.