I recently got a new umbrella cockatoo baby [Around 5 months] yet he refuses to eat veggies or fruit. He only wants to eat sunflower seeds. I've been offering him a parrot mix [Seeds, Nuts and Fruits] as well as freshly cut veggies and fruits daily but he still will only eat sunflower seeds. Any ideas on how to entice him to eat veggies and fruit? Thank you!