I brought home my new cockatoo on Friday. He's been weaned for the last 4 months and the breeder is reputable and knew that he was off hand-feeding and ready to go home. The bird is eating his pellets and seeds (no fruits/veggies yet, but we're working on that) and is otherwise perfectly fine, has a clean bill of health from the vet, etc. I started trying to clicker-train him with a treat incentive, but as soon as he realizes the treats are nearby, he starts making the baby food-begging noises, for lack of a better term. I don't want him to regress and think I'm encouraging this behavior, so I stop training immediately and put him back in his cage. Nothing but putting him back in his house will get the begging noises to stop once they start. This has happened more than once.

How should I be handling this?