Gosh I hate to say it...but I wonder if something medical could be going on? Caique's are known as the clowns of the parrot world...Mine loved leather strips with knots that he could untie..and beads that he could make crash to the ground all the better...bells...ect...This is the breed of bird that I try to talk would be Macaw owners into getting because my experience with them is that they are as much fun to watch and play with, smart, ect. These guys are usually constant motion...extremely playful. Not an expert since I only owned one...but with him as an example, and other people that I have talked to that had Caiques...I have never heard of one that didn't play or wasn't active? I think you should get a full blood work up done on this bird, make sure doesn't have something like zinc poisoning...unless maybe this bird has had a lot of trama. I do know they have very long memories. Had to give mine meds for 10 days one time....after day one he gave me the evil eye everytime I went to step him up...and it took 6 months afterwards to win his trust back...he never stopped stepping up for me, and to his credit he never did bite me, but I could tell by his body language that the full trust was gone for awhile, and I wasn't sure if I was going to get it back. I still think I would go for a full blood work up though...if it was my bird, just to be sure you are dealing with a healthy bird...