Anthropologists have observed a group of chimpanzees enjoying a particularly strange delicacy deep in the forests of Gombe National Park, Tanzania.
During their study of the group, they watched the chimps hunt down and eat dozens of baby red colobus monkeys. Strangest of all, the chimps almost always started eating the monkeys by biting open their skulls and tucking into their brains. On a few occasions, brain-munching hungry chimps have even been observed using sticks and leaves to extract the last bits of brain matter.
When you think of a chimp’s diet, you probably just think of bananas and leaves, but this species of great ape does have a taste for meat. Figs alone make up 50 percent of a wild chimp’s diet, while meat accounts for just 5 to 8 percent of it. They're also partial to eating insects, eggs, bark, and honey. Remarkably, a chimp's diet is often cultural and varies from community to community.
Carnivorous behavior was first documented in chimps by Dr Jane Goodall in Gombe National Park during the 1960s and it's since become relatively common knowledge. Researchers have even observed chimps using spears to hunt sleeping bush babies in Senegal. However, this particular method of brain-munching is still relatively undocumented.
As explained in a study from the International Journal of Primatology, there are a few reasons why the chimps could be doing this. First up, the brain is actually surprisingly nutritious, plentiful in calories and rich in long-chain polyunsaturated fatty acids, which are useful for neurological development. Equally, the study explains that the “skulls were relatively easy for chimpanzees to break with a single bite.”
"In our study, chimpanzees ate the brain first whenever it was possible to do so - when the prey was subadult. The skulls of subadult monkeys are easy to crush, compared to the more robust skulls of adults," lead author Ian Gilby, an anthropologist at Arizona State University, told IFLScience. "When in possession of adult prey, chimpanzees started with the head about half of the time, choosing the soft abdominal organs instead."
It’s fairly common for animals to hone in on a particular part of the body when hunting. Grizzly bears, for example, also eat the brains, eggs, and skin of salmon first as these parts are highest in energy. Wolves will also first consume the fat-rich liver of their prey before turning to the flesh of the large muscles.