Hello and welcome to you and your flock! As to how greys tell the difference in human gender, I really don't know. That's an interesting theory you mentioned.
Hello and welcome to you and Dooble! My TAG, Timber is 9 and we still don't know if he is a he... You won't be able to tell by looking, the way to find out is bloodtesting if you need to know for sure.
I honestly don't know in answer to your question about "fledgling." Hopefully someone who does will see your question. So glad to hear Poppy has "weathered the storm!"
LOL! I am certainly set in my ways and can totally commiserate. In fact, I would probably have regressed to hair pulling/feather plucking/overpreening and biting by now... Hang in there!
Timber has also eaten one that I accidentally left in his portion when he was sharing dinner with us. Like Sterling, I try to pick the mushrooms out. But Timber is fine and didn't seem to suffer any ill effects. It's important to remember (though I don't know if this is true of mushrooms) that foods that are bad for them can have cumulative effects (salt and sugar come immediately to mind). So, if Timber eats a bit of those types of thing I know it won't kill him, but I also know that his digestive system doesn't work like mine and things can accumulate over time and causes damage.
I don't cover Timber, but that is mainly because his previous owner didn't cover him. He goes to bed when we do, an like GreycieMae he fights it every step of the way (most nights). I think he sees it a game, but that's our routine. Like you, I've learned to tune out noise over the years and we sleep on the second floor, so no problems here.
Giannine, the vet says Timber is just a small TAG, but healthy. He wasn't on a great diet when I got him, but he hasn't gained a lot on a better diet. He's just... small.
I haven't been able to find anything about the age at which they have attained full physical size, which is surprising. Timber was 5 and grown when I got him so I'm not sure. Anyone else know?