Why do cockatiel birds throw up mine does everyday then eats it?

Regurgitation is a normal behavior in cockatiels and other birds. It serves several purposes:

Feeding Chicks: When a cockatiel pair has chicks, the parents regurgitate food to feed their young. This is how they provide nourishment to their offspring.

Bonding: Cockatiels may regurgitate food as a way of bonding with their mate or other flock members. It's a sign of affection and trust.

Courtship: During the breeding season, male cockatiels may regurgitate food as part of their courtship display to attract females.

Territory Marking: Some cockatiels regurgitate food as a way of marking their territory. They spread the food around their cage or living area, which sends a message to other birds that the space is occupied.

Nutritional Needs: Occasionally, cockatiels may regurgitate food if they have a nutritional deficiency or if they are not getting the proper diet.

If your cockatiel is throwing up every day and then eating it, it's likely a normal behavior related to one of these reasons. However, if you are concerned about your bird's health, it's always a good idea to consult with an experienced avian veterinarian. They can assess your bird's overall condition and determine if any medical problems need to be addressed.