I know! I wonder if they have warning word for 'humans'?

insert joke about spanking a bad monkey...

yeah i don't think 'calls' are quite language, and i think a lot lower animals than Monkeys probably have unique sounds for different situations. (perhaps even as specific as the case they're giving). another test would be to take a different colony of monkeys and see if they have the same 'calls' and if they can understand eachother's 'calls'... it may tell you if its something that's learned and evolved or if its something hardwired in their brain (like how being angry at a dog works no matter what language you curse at them in)