Also a newbie... but I'd gather that each of the "sign-post" characteristics strongly increase the probability that the subject is a human. So, if you look for "things that are bipedal and featherless" - you have a strong likelihood of finding a human... ie it doesn't necessarily mean that if a thing doesn't have that characteristic, that it isn't human ie A->Human doesn't mean that ~A->~Human though if you find ~A then Human has lowered probability. I reckon you can probably sum across the cluster and as long as it has a good percentage of the signalling characteristics - you'd have a high chance of Human.

As to furries and plucked chickens. I'd assume that a temporary-characteristic shouldn't be taken as a permanent characteristic. eg a plucked chicken is temporarily un-feathered (and not by its own choice either!). Normally (for that chicken) it is feathered... the opposite is the case for furries ;)