One of the most common questions that we received from new cockatiel owners is about a cockatiel not eating very much or not eating at all. For cockatiel owners who have just brought a brand new cockatiel home from the pet store or a breeder, this is very normal.
A cockatiel that is new to its surroundings might be stressed because it's out of its "comfort zone" and familiar surroundings. Give your bird a chance to get accustomed to it's new environment, including its new cage and views. It's extremely important that you use the same food that the bird was eating at the store for the time being, cockatiels are notorious for getting accustom to particular type of feed.
"Other reasons why a cockatiel might loose its appetite are for example, if it's introduce to a new feed that the bird does not like, the temperature in a room, or a cockatiel that have lost his appetite due to grieving over the loss of a companion."
If you have had your cockatiel for a while, and see a decreased in the consumption of food intake you might want to investigated a bit further why. Just like humans, cockatiels do get upset stomachs and their appetite might be off for a day or too. If your cockatiel is not showing any signs of illness like being lethargic, not perching, being at the bottom of the cage or being fluff, you should not worry about it. If any of the symptoms mentioned before occurs, do take your cockatiel to an Avian vet as soon as possible.
A healthy cockatiel would not starve itself to death. Once they are hungry enough, their survival instincts will kick in for feeding.
As always the information offered here is to provide guidance and is not intended to be a substitute for the good advice provided by your own avian vet. When in doubt always consult your own veterinarian.