Less then half of the males that participated exhibited signs of actual aiming and rarely hit their target. They tried throwing both overhand as well as underhand. During the banana episode observed, as the frequency of aggression increased, more males engaged in it as well as youngsters as well as one adult female chimp. As it went on the ration of hit per miss increased as well.
This observation means to me that they might be conscious that they are tapping into a possible breakthrough but cannot yet realize the possibilities of what regular spear throwing could bring. I believe it is yet generations from possibly their true realization of the usefulness of the spears or "missiles". It is becoming instinctive however but not yet as refined yet as is their tools for fishing termites.
In a rare instance, a Gombe adult male, Mike, threw a sizeable rock (25cm x 10cm x 10cm) at a group of brush pigs, striking one. He and his companions had surrounded the pigs and when the pigs retreated into the brush, Mike and his companions caught a piglet and ate it. In an earlier observed instance, Mike had used a 4 gallon kerosene can to display and bluff his way into the pinnacle of the group, past the before leader, Goliath. Since that instance, he has been knocked from his position of power.
This tells me that there are chimps with a higher capacity to understand weapons and the abilities of them. He however didn't fallow up on this as much as he could have. It is puzzling that they fear things like that but cannot grasp it enough to consistently use weapons for hunting and some other purposes. .
In one observation in Bossou, chimps threw underhand sticks of 100-400 cm in length at their observers. Their effectiveness and accuracy unfortunately was evident on the observers. They would climb a branch into a position nearly right above the observers and hurl them underhand. After further observation, when the chimps were further accustomed to the human observers, they stopped throwing sticks at them.
