Hello. New member here, with a question that is quite generic but of course seems special and important to me.

The long(ish) story is this: I had a pair of budgies. One died (of Going Light Syndrome, apparently) and, since I was about to go on holiday right then, I put the other one (Mustard) in a bird hotel so it wouldn't be lonely. While I was gone, the bird hotel had a psittacosis scare. (Someone brought in a sick chicken by accident.) Anyway, Mustard was tested and found negative, and I was allowed to take him home three weeks ago.

So, because of all this woe, I am now extra paranoid about his health. At the start, I was very worried: he was quiet, sitting just in one spot, eating very little... and his tail was bobbing. Not all the time, and not a lot--just a couple of millimeters. So I took him to a vet. His tail was annoyingly stationary during the checkup, and the vet gave him a hand-exam only (no lab tests.) He concluded that the budgie seems very healthy, and some behavioural weirdness is normal given all his recent stress, but I should keep an eye on him.

Well, I have. I have also tried to relieve his depression by getting him a friend. The new bird is currently in a second cage for quarantine reasons, but in the same room, and seems healthy... and the difference in Mustard has been enormous. He now eats normally, runs around all over the cage, preens like crazy and makes up his usual complicated budgie-songs. He looks, acts (and poops) like a healthy budgie...

...but the tail-bobbing keeps recurring! I don't see it every time I observe him, and of course observations made when he is chirping (which is much of the time) or recovering from an exercise session have to be discounted, but a couple of times a day I will see that little up-and-down motion while the rest of the budgie seems to be at rest. And I have no idea whether this is a new problem (well, a problem of the last three weeks) or an old one, because I never looked this closely before, and it's not that obvious a motion, nothing like the tail-metronome I saw on my dying bird.

Should I take him back to the vet? I am pretty sure the vet himself would say no, because he thinks vet visits stress a bird's system and should not be undertaken lightly. If I saw any other symptom, I would press the point, but there's nothing.