What happened to your fourth budgie? Besides Snowy, you had Nova, Cloudy and Winter.
@bur is 100% correct.
You keep changing your story. Why would you write one thing initially only to change it in the very next post?
Here's something more clear.
Snowy sometimes fluffs up. A few days ago, he was very fluffy. Now he's not.
I do have Nova, Winter, Snowy and Cloudy in the same cage. We're not sure why he got the wound(? Idk) on his cere, because when we first got him, he already had it. They fought really badly during the first few days then it started dying down. Fighting with the other budgies does typically happen everyday but Snowy doesn't get hurt in these fights. And the fights aren't too extreme, except for Winter VS Nova which is rare. They have been fine today, no major fights so far. We're not to keen on breeding budgies, but we'd like to try. And we don't think we have a choice since we only have one cage, 4 untamed birds, and no separator. As a result, we try to limit daylight hours so nothing happens.
Snowy STILL fluffs but he's active, and eats properly. Sometimes he fluffs, sometimes he doesn't.
I'm sorry for any confusion, English wasn't my first language and sometimes I forget how to put things in words.