is he pooping? What are his dropping like? If he isn’t pooping his crop is impacted. The food in his crop has gotten stuck together into chunks and is blocking the hole where the digested food would go down. He needs to have his crop drained. You can take him to the vet and they will take a...
She is probably moulting, right before the tail is a common spot for a molt to start because it is near the preen gland.
You may also want to see if she is getting picked on by other birds
Have him drink so,e hot water and slowly massage his crop. This will help break up whatever is stuck. If it doesn’t improve you might have to do some more serious things. Surgery is an option but is still very risky.