Cockatiels have a little storage pouch called the crop. In this little pouch your cockatiel will have semi digested food and other fluids. Your tiel might regurgitate these contents to feed the young, sometimes for courting another cockatiel. In other instances when regurgitation is very frequent it might be a sign of illness, like a possible infection or problems with your cockatiel's digestive system.
For some cockatiels regurgitation is a sign of affection and caring. We have seen cases where a lonely cockatiel might try to regurgitate towards a favorite toy or even a person who the cockatiel loves. If your tiel regurgitate towards you, your cockatiel is just showing a sign of affection and is trying to feed you.
If there's a digestive issue or and obstruction in the digestive track, a cockatiel might try to regurgitate, if this is the case do seek veterinarian advice.
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.
Vomiting vs Regurgitating?4> Sometimes it can be difficult to tell the difference between regurgitation and vomiting. As explained above, if the incidents are very frequent and your cockatiel does not have young chicks to feed or another cockatiel that is trying to courtship, this might be a sign of illness, like a possible infection or problems with your cockatiel's digestive system.
A cockatiel that is regurgitating will often bob its head and stretch out its neck, and the food does not look digested, whole seeds are regurgitated. Other reasons for regurgitating are courting behavior to other birds, mirrors, toys, or even owners, as a sign of affection (your cockatiel is giving you a gift). In addition, motion sickness, excitement or stress can also induce regurgitation.
Vomiting is more of a spitting action, and the bird shakes its head from side to side. Vomiting is a sign of illness and should be evaluated promptly.
Source: Cockatiel.com