Which kind of foodstuff does the bird consume; will it have most loved treats? Has the bird been to some veterinarian? When you are buying a youthful bird, ensure it can be fully feathered and totally weaned (isn't going to should be syringe fed or father or mother fed). Indications https://birdparadiseaviary.com/product-category/birds-for-sale/cockatiels-for-sale/