Great! A picture is truely worth 1,000 words
Well as much as you can tell from one still shot, three of them are looking pretty good. Having the pin feathers is a good sign, meaning the feathers are growing back in. My guess is a "mini-molt" triggered by the stress of illness.
If you have the ability, I would seperate the Normal Black Male, since he's still showing signs of illness. Any small cage can be converted into a quick hospital cage if you have the means. I've found that seperating out the "sickest" of the flock allows all the birds to heal more quickly. The "sickest" bird get's "special" treatment, in that there is no competition for the water or food dishes and s/he can eat and drink at their pleasure, and the healthier birds don't have any one bird to single out and pick on.
As I was getting at in the other thread, since the anti-biotic doesn't seem to have much affect on the Black head male, you may want to look into the possibliity of a yeast infection (brought about as a 2ndary infection from whatever bactiera got there in the first place).
My logic in this: Airsac mites weakend the immune systems of your birds allowing a bacteria (once suseptible to Amoxitex) to invade. That further weakend the immune systems and possibly allowed a yeast or another bacteria that is not suseptable to Amoxitex to invade your Black Head male.
My understanding is that Amoxitex is based on Amoxicillin. I am not an Avain vet, but have you considered trying a sulfa based antibiotic?
Recently my Gouldian flock started to show signs of illness a few weeks after I had a mysterious death of one bird (he just dropped over showing no symtoms). I put them on a product called "Marvel Aid" (active ingrediant is Sulfadimethoxine) a sulfa based antibiotic.
Marvel Aid is packaged in a drinking solution, and is meant that you replace the drinking water with this solution as the only source of drinking water for 5 days (instructions on package).
After placing the sickest of my flock in a hostpital cage I was able to get him to my Avian vet a 2 days later, and at his exam the Vet said he was in very good health, and he said he could not tell the bird had been sick, other than the symtoms I had described to him. In this case, I basically got "lucky" and whatever infection the bird had was treated with this sulfa based drug.
My avain vet instructed me to keep the entire flock on the medicine for 7 days (instead of the recommended 5) and then to call him with results. After only 2 days on the medicine they are all acting healthy and normal, but I'm going to keep them on the treatment as the vet told me to, since you should always finish out any Antibiotic treatment to prevent "super" strains of bacteria. ( For those of you interested you can get some here:
http://www.drsfostersmith.com/product/p ... catid=6089)
If your bird has a yeast infection, I do not think this drug will kill them, but I'm not sure, because some other sulfa based drugs have been shown to kill yeast. (Certain Sulfa based drugs are used to treat female yeast infections for example.)
Anyway, I'm pretty much "thinking out-loud" here...
