Hello everyone! A quick update. Napoleon has been improving, slow but steady. He's a still a bit wobbly, but his movement has improved dramatically. He can reach the highest swings in the cage, and can even preen and nap while balancing on the swing, when before he lost his balance preening on a regular, lower perch. He's more active, he never sleeps at the bottom of the cage anymore, he explores the rest of the cage top to bottom and can balance on most perches, and he's chirping more. He's set to go for another check up next Monday, just to make sure everything is okay.
A separate problem has come up, however. While Napoleon had been sick in October and November, one of the female budgies had begun laying eggs. I replaced the eggs she laid with dummy eggs as instructed by my vet. This hen was usually a bit bossy to the other budgies, but she was never really aggressive. In fact when Napoleon was well she would accept food from him and he would chirp to her. Starting November and December, she started to get aggressive with Napoleon. She would stare him down and peck at him. It was really strange, because ever since I bought Napoleon back in February 2021, she was never aggressive to him at all until about November. I'm thinking the change was caused in part by her laying eggs and being more hormonal, as well as the natural instinct to drive away sick members of the flock.
My first thought was to separate them, so I put her in the hospital cage. During this time she seemed to lose interest in the eggs, so I removed the eggs from the cage. I kept her separated for about two weeks, then decided to try to have them in the same cage again. The first week back, at first, went really well. She didn't pay much attention to Napoleon, but she also wasn't bothering him. All four budgies seemed to be living together again in relative harmony. By the end of the first week back, she was spending more time at the bottom of the cage ripping up the paper, which made me worried she was going to start laying eggs again. During the second week back, she would occasionally make Napoleon move from perches and peck at him. At this point, Napoleon was a bit stronger and he would peck back, so initially she would retreat. But this Sunday she laid an egg, Tuesday she laid another egg, and today she was again preventing Napoleon from approaching the food bowls and staring him down again. I didn't want to wait for it to get worse, so at least for now, I've separated her again.
I know sometimes two budgies just don't get along and need to be housed separately. If that becomes necessary, that's what I'll do. But part of me would like to keep my four budgies together. The three older ones all clearly have some affection for each other. Napoleon is the youngest and does well with the other two budgies. And when this specific female budgie isn't laying eggs, she usually at worst ignores Napoleon or actively seeks him out as a mate. Napoleon for his part used to chirp and head bob to her when he was well. Since she started being aggressive, he's become fearful of her, so now he just tries to avoid her. Like I said, before Napoleon became sick and before she started laying eggs (both things happened in October and November), she was never aggressive to him at all. I've tried reducing the daylight hours and rotating the perches in the cage to discourage egg laying, but that hasn't seemed to have discouraged her. I do plan to talk to the vet about this when it's time for Napoleon's visit. I'd really appreciate any advice on how to handle this situation. Thank you very much for all the advice already in this thread.