I'm not sure whether or not I'd class them as separate species. I mean, they're basically human for most of the time, except, of course, for the fact that they can transform into an animalistic form, which your average human cannot. I think the defining factor would probably be just how one becomes a were. The general way of spreading lycanthropy, of course, is through a bite - if you get bitten by a were, you will become a were yourself. This would not, however, account for the great amount of weres that would be the basis of the series, so let's say it works like this - lycanthropy may indeed be spread by a bite. Once there, however, it is an inherited trait - the children of the bitten were acquire it while still in the womb, and are born weres. This brings up identity issues - do the children consider themselves different species from the father or mother, or are they still the same species, just with an added trait? Is there a sort of were aristocracy, where families who have had lycanthropy passed down through the family line for generations sneer at the newly-minted weres who have just been turned, or their children? For that matter, what if it isn't always spread evenly - what if, for example, a werewolf has two sons, and one of them is born a full-fledged werewolf, while the other is a regular human? Would the human brother still consider himself a werewolf? Would he get along with his family? Would he disassociate themselves from them, and try to live like a 'normal' human? And if he decided that he wanted to 'convert' to being an actual werewolf, could he, also, acquire lycanthropy through a bite, or does he already HAVE lycanthropy, and it just doesn't work? Are there were clinics for this sort of thing? There's all sorts of interesting issues to be dealt with.