Can chimps plan?

Daniel Gilbert and others have earmarked planning and experiencing the future as the abilities that separate humans from animals. The idea is that unlike primates we have a fine-tuned capacity to simulate and "pre-feel" what events in the future will be like. We can then use this information to guide our plans and act in accordance with long-term goals. We already know chimpanzee's can do all sorts of intelligent things when needs be like using the rocks to crack open nuts and potentially even sign language. Now, Santino a chimpanzee at Sweden's Furuvik Zoo is doing his utmost to try to show that yes primates can plan too! Santino thoroughly dislikes visitors. So much so that in line with some contemporary attitudes on how to treat young children he stockpiles rocks to fling at them every day. This behaviour may be a random classically conditioned act he's built up. Like the horse 'clever Hans' who people thought was extremely brainy (he even knew algebra) he may be in reality just responding to a simple prompt from the environment (noverbal cues from his owner in this case). But more interestingly, Santino's rock hoarding may mean he is using his powers of foresight to anticipate the thrill he gets from putting the run on tourists. He may be mentally preparing himself to meet his goal of some peace and quiet. Only time and methodically planned, controlled experiments with random assignment will tell!