My cockatiel Coco 5 months old has his wing dropping and is really sleepy. His wing was like this earlier today when he didn’t land correctly. So we took him to a vet and they said it was due to an abnormal blood feather so they pulled it out and then he was looking good again. About 20 minutes ago though he was walking around like normal and then he dropped his wing again. He is still eating and drinking water but he’s not as active as he usually is.