Chimpanzees mostly eat fruit but occasionally supplement their diet with meat. A common prey is other primates and chimps have developed some fairly complex tactics for taking them down, often flanking around to force their prey into a trap where another chimp is waiting to ambush them. However one group of chimpanzees have taken things a step further and started hunting with spears.
The Savannah chimps (so called because they live near the edge of the forest) hunt bush babies; a prosimian widely regarded as “cute”. Bush babies are nocturnal and hide in tree hollows during the day. They’re adept climbers so if a chimp were to try and reach in and grab them they could easily escape. To counter this the Savannah chimps have started breaking off tree branches, stripping off the bark and then sharpening the end with their teeth.
They then stabbed their spear into the bush baby “nests”; after which they would break open the tree and pull out their prey. Although the researchers couldn’t see if the bush baby was killed by the spear, they did note that “it made no attempts to escape, nor did it utter any vocalization.” The chimp then ate their victim (interestingly, they did not share it with other chimps as is the norm).
This makes them the only known animal (other than humans) l to use tools to hunt vertebrates.
The primatologists were also impressed with the complexity of the spear, requiring more steps to create than most other chimp tools. Not only do they sharpen the tip and strip the bark, but they also typically trim the tips of the tool first. This helps remove any damage caused by them snapping the branch off the tree; creating a more durable tool. This indicates a high level of planning, intelligence and murderous intent.
Next they’re going to figure out fire, then we’re screwed.
Pruetz, J. D., & Bertolani, P. (2007). Savanna Chimpanzees,< i> Pan troglodytes verus</i>, Hunt with Tools. Current Biology, 17(5), 412-417.