Chimpanzees can be pretty aggressive apes, to say the least. They often get in spats, and it’s not unusual for males to violently attack females or even engage in infanticide. Still, it came as a bit of a surprise when earlier this year, a captive chimp managed to swat a drone that was skimming through the air to film their behavior. But was this just a reaction brought about by fear, or was it a calculated act? According to a new study, the latter is far more likely.
As described in the journal Primates, the incident occurred on April 10, 2015, at the Royal Burgers Zoo in Arnhem, Netherlands, when a Dutch TV crew was filming residents. They wanted to get up close and personal with the chimps, while still keeping a safe distance, and document the animals at various different angles. So the team settled on a camera-laden drone.
Before recording commenced, the crew went through a practice run that seemed to stir excitement among the chimps. As it whizzed around the enclosure, humming as it went, a few of them grabbed a stick and four left the ground to climb the scaffolding near to where the drone was hovering.
No one thought much of it at the time, but what happened next was fascinating. When the drone was sent up again, this time with the camera switched on, the chimps had calmed back down, so the crew decided to hone in on two females that seemed to be chilling out on the scaffolding near to where the drone had been hovering before.
Oblivious, or perhaps ignorant, to the fact that they had carried a massive branch up with them – almost 2 meters (6 feet) long – the operator maneuvered the drone towards the pair. One of them, Tushi, then went for it, swiping at it twice with her weapon of choice, teeth bared and grimacing. Second time lucky, she managed to smack it out of the air, showing no signs of fear. Broken yet still managing to film, the drone captured footage of other curious chimps surrounding it cautiously at first, poking it with sticks, and then going ape over their new toy, chucking it about until they got bored.
According to the researchers, these events are strongly suggestive of forward planning of tool-use, in which the chimps grabbed the stick in order to either attack the drone, which would be agonistically motivated, or investigate the drone, which would be motivated by curiosity. However, the authors note that they cannot rule out that the attack was a defensive reflex action, but the fact that she did not show a “fear” face does not support this notion.
While members of this group are known to spontaneously and adaptively use tools, especially sticks, they had never been taught to use them. But being in a zoo, they have likely seen a whole host of people using a variety of objects for different things, which could give them ideas.