Personally, I would have done it differently. I trust I'm right in saying these are youngsters which you've obtained. You have to realise and understand these have suddenly been moved from their birth - place, their parents whom they had total dependence on and their home. Everything is now new to them. They are scared and hungry. Food , at this time, should not be rationed.....but should be constantly in front of them....... always available. Rationing food can come later. As someone has already said, keep monitoring their eyes which will tell you they need water, but there's no problem in 'dipping' their beaks in the drinker. They will probably only need that bit of help once, possibly twice, and they'll soon have the hang of it. Best of luck.