Unlike most species of birds, where there is a visiable differnce between the males and females, guinea owl do not always show one. The best way to sex a guinea is by the sound they make. A male will male a 1 syllable sound, whilst the female will male a 2 sylable sound, sounding like 'come back, come back'.
Agression
Guinea fowl males wil lnot fight each other, even if there is a larger sex ratio of males to females. Though it is advisable to keep more guinea females than males. However guinea males will attack and kill cockerels, and other male birds. Therefore if you have a guinea male, do not keep it with any males of a different species. Though some are okay, it is better to be safe than sorry.
All guineas are usually agressive to new birds. Therefore it is best to keep new birds penned insight of the guniea fowl for a few days, before imtroducing them properly to the rest of the flock.
Guinea fowl are also prone to attacking chicks. Only let chicks out if they are with a broody, who will protect them agaisnt the guinea fowl. If the mother does not protect her youngsters, pen them up until they are older. Chicks hand rasied or bought in shoyuld not be let out with guinea fowl until at least 12 weeks of age.