The Walking Recall
You can train a parrot to do recall at any age. Clicker and recall training is wonderful for a number of reasons. It strengthens the bond between bird and owner, it keeps our intelligent companions intellectually stimulated, it gives much needed exercise a structure that helps to keep it safe, and it gives us a tool that helps us more easily retrieve our birds if they should ever accidentally get out of the house.
The very first step in recall training is called 'the walking recall.'
Anyone can do this by calling their bird as though they were calling for a step up with a command like 'come here', Place your hand or finger or perch a few inches away so they have to voluntarily come to it, When they step up,click, treat with a safe treat like an almond sliver, and praise lavishly.
It is best to do this right before a meal, as any of are able to exercise more freely if our stomachs are not full, and the treat is appreciated more.
This is just an easy step to start with. I have a big eclectus boy here that couldn't care less about the food treat, but he would fly to the moon and back if I would make a big fuss and tell him in an excited voice what a good, smart boy he is.
The key in any training it to 'reward' the behavior. Each individual knows what motivates his bird. Food is good, and works best if it is offered before a meal. This is not to starve or threaten or scare a bird. You are asking your bird to be an athlete, and it is easier to exert yourself physically before a big meal, rather than after. Some of the energy used normally to think or to react is diverted to digesting, so they are more sluggish and would have to work harder and have less concentration.
When your bird comes running to you consistently, try putting your hand back a little farther so he has to really stretch to reach you. Do this for a couple of days, and let him get used to the idea that coming to you is a rewarding experience! Then, make the distance such that he can't walk to you or stretch to you...he has to make a tiny hop. Don't forget to be excited when he does something correctly, but to ignore with no reward when he doesn't.
Don't train for longer than 15 minutes at a time. you don't want your bird to get bored or frustrated. Feed immediately after the training.