Hi Kunju, yes, pigeon-proofing. Windows-wise there is no issue since I live in a Manhattan high-rise where windows are blocked from opening more than a crack because of legal reasons.
I mentioned I've been shopping for a cage or aviary. No idea really how big or small it should be. The bigger the better for Mr Pigeon, I suppose, but again there has to be a balance.
I do only keep 1-2cm of water in his dish just in case. He does have perfect balance, is able to pick up seeds with sharpshooters' aim, stands on one leg often and all around appears very comfortable. Quite often he lies down altogether on either wing and dozes off, especially in the sun. When he wakes up he's energized, looks around with curiosity, runs to his food, and eats his seeds in order of color. First up are the red and the green ones, and then it's on to light-brown. He doesn't care for the black seeds so those stay behind. Finely chopped parsley is ok, but other vegetables I've tried he systematically throws out of his dish with vengeance.
Quite a character, this Mr Pigeon!
His head inversions are still there, but at lower frequency than before. He almost always recovers within a second as if he's willing his head back up. He also practices flying several times a day, usually in the early evening, and is able to hover more easily. He always lands on his feet now, in perfect control. He has also gained weight, his feathers are filling out nicely, and he spends lots of time arranging them just so.
Cheers,
Michael