I'm still uncertain which are male or female, I thought maybe the ones manny(the oldest one that has been singling some out) was being aggressive to were the males, but one that I was sure was male because they were aggressive and loud, manny doesnt bother, and one that is very quiet that I thought was female he has outcasted. It got to the point he was scaring even the ones he wasnt generally attacking, due to him seemingly getting confused as to which ones were which and biting at one before realizing they were the 'ok' one. So I've had to just seperate him, and I feel so bad because I had only gotten them so he wouldnt be alone

I assume maybe its 'breeding season' and all of them are too young to understand since they're not even 6 months old, I havnt seen any attempt breeding, including manny, hes just being extremely aggressive to some.. I'm not certain if I should even try to sell any since i dont know which are which and why hes picking certain ones out even when they seem to fit female characteristics, or ok with ones that seem male.
The white one that's closest in the first and 4th pic is one i thought was male.
The ones I assume male are ones that are extremely loud and stand around honking and chewing on my shoelaces(not aggressively) while the quiet ones walk around and eat and generally avoid me.
Oh and I bought them online for about 10$ each as goslings, so I'm not sure how great quality they are. One of the Africans actually has white around its beak and another has a white spot on its neck so I'm not entirely sure they're purebred either.