Lemur body language help?

[Akuma223]

Hello all, Where I volunteer I get to interact with one of the four ringtail lemurs at the facility. He's a young male thats maybe a year old? Anyway, I think he may be reaching maturity and is beginning to show types of behaviors I see in the older lemurs. I don't go in with the older ones because they are too unpredictable, though even though I watch them I still find it hard to decipher their behavior. Their body language is far different from what i'm used to. So does anyone know of where I can read up on lemur behavior and vocalizations? He's beginning to make me a little nervous because I don't understand what he's trying to say.