Excuse me, how many months has this budgerigar been? Is this wearing a hat?

Cut to the chase and see the answer. Simply put out the questioner's doubts, it is no wonder that birdies make mistakes in the discussion. The questioner raised the question of judging the age of budgerigar. The questioner provided photos of budgerigar and pointed out the problem of wearing a hat. Let's briefly discuss the age judgment of budgerigar. Usually we observe whether the feathers on the budgerigar's head form a uniform color, which is often called "wearing a hat". Wearing a hat means that the feathers on the budgerigar's head turn green, yellow, blue and white. Based on this, it is speculated that this original budgerigar has been wearing a hat and is about six or seven months old.

Having said that, it is no wonder that the bird friend is wrong. The above is only personal breeding experience, for reference only, I hope it will help you.