One of the most basic principles of having a multi-parrot flock is that each member of that flock becomes a different personality depending on who is in the room, what time it is and who is not in a cage. A flock of more than 1 parrot is the most fluid and organic organism you'll ever encounter. Which is why parrots and birds flock. Safety, fast response times, viable health and territory.
One of the most common "needs" I address in my work is a change of character when introducing a new parrot member in a home. Not all birds react to a new member coming in, but there is a percentage that is high enough to keep me busy online, on the phone and in the home of clients. When you bring a new member into your home, the rules change immediately. When the rules change, a bird's attitude and personality change to accommodate the unknown implications.
Another angle to organic flock change is the return home of a spouse from work or travel. Our cockatiels never change. They are bullet proof, if you will. Felix, Butters and Snickers are VERY sensitive to dad being around. Kirby is happy as long as he is out of his cage. He can't believe we even got one of those cages for him. What was the point of that!?!
Weekends can be tricky for me. Dad is home. I am no longer necessary. I may be an interesting distraction, but I have to wait my turn and read those body languages to know if I am just that. During the week, I am loved, attached to, kissed, offered toys, offered food, greeted, flock called and all together worshiped.
Saturday morning I am Friday's refuse.
And so it goes. The flock hs organically changed with the inclusion of dad. I do not attempt to change this with "training" or positive reinforcement or other gimmicks. I believe that parrots should have the opportunity to change in this way. It is healthy for their mind and spirit to be allowed to organically modify as they would in a flock. They are not my pets. They are my companions. And so, it may make some days more challenging, or leave me all alone at times, but I embrace this time. For it too, is as much a gift to my birds as a new toy, a kiss or a bowl of food.
When you are addressing a sudden change in your bird, or a consistent change during certain times of days or weeks or even months, consider the balance of your flock. Somewhere a small but important element has entered their notice.
If you are bringing in a new parrot, remember the CURRENT flock member(s) take full precedent. Do not change a thing about their world or their schedule. Require the new member to work around the CURRENT flock. Transitions, changes and the organic balance will return much faster if you approach the flock with the usual things while they understand the unusual new member.
Parrots do not mind change, as long as the change isn't in their primary communications.