Watch: Scientists Observe Chimpanzees Smashing Open and Eating Tortoises for the First Time

chimpanzee, tortoise
Chimpanzee eating a predated tortoise. Erwan Théleste

Like humans, chimpanzees are known to hunt and consume the meat of various animals in addition to eating plants.

Now, scientists have observed chimps preying on tortoises for the first time, according to a study published in the journal Scientific Reports. Until now, there has been no direct observation of such behavior, although some previous studies had provided indirect evidence for it.

Simone Pika from the University of Osnabrück, Germany, and colleagues witnessed the behavior in a group of wild chimps living in the Loango National Park, Gabon—a country located on the Atlantic coast of central Africa.

Over the course of their research, the scientists recorded 38 separate tortoise hunting events among 10 individual chimps—34 of which were successful—between July 2016 and May 2018. In fact, most or all of the adult chimps studied were observed frequently preying on tortoises.

Intriguingly, the researchers say that each of these tortoise hunts consisted of a distinct sequence of behaviors: After discovering the prey, the chimps would smash the shell with one hand against a hard surface, such as a tree trunk.

The apes would then climb a tree to consume the meat, and, in many cases, the food was shared between individuals, including those who had previously attempted to open a shell but had not been able to.

In addition, the team observed one case of food storage, in which an adult male placed a half-eaten tortoise in a tree fork and retrieved it the next day to continue eating. To date, such storage behavior in primates had only been implicated for early hominins, the researchers say.

The ability to use tools was once thought to be unique to humans, but it has now been observed in a variety of species, including crows, sea otters and bottlenose dolphins. Chimps in particular have developed an exceptionally large repertoire of methods and technologies to gain access to food.

For example, they have been observed using spear-like objects to force prey out of small inaccessible cavities. They are also known to use so-called "percussive technologies"—pounding food items such as hard-shelled fruits, nuts or snails against hard surfaces or using hammer-like devices to reach the edible parts.

And one study published recently in the journal PLOS ONE even documented how chimps in captivity spontaneously worked out how to use tools in order to dig up buried food.

"Our observations shed new light on the hitherto little understood percussive technology of chimpanzees, and expand our current knowledge on chimpanzees' dietary and predatory repertoires with respect to reptiles," the authors wrote in the study, arguing that the latest findings are further evidence of chimps' high cognitive abilities.