Oh sorry, I assumed duke was a new bird so he would be in quarrentine. Very tired and mixed up at the moment, it's been a horrendous day and I must have got you mixed up with someone else

If it is not normal behaviour for your bird then keep an eye on him and get him to a vet if it persists.
Is the family room one he is used to being in? if not he could be acting more alert than he really feels because it is a strange environment and he doesn't want to appear vulnerable. Ollie did that to me at the vets, we left him in for tests and I had just been telling the vet how quiet and depressed he seemed. Turns out he was as lively and inquisitive as can be at the vets but soon went quiet again after we returned home. If it is a room he is used to then he may have just been a bit extra tired earlier on. Did he go quiet again after you returned him to his cage?