Meat-eating chimps that hunt baby monkeys prefer to eat the brain first

Scientists have made a new discovery about chimpanzees’ diets.

One anthropologist from Arizona State University, Ian Gilby, led a team that discovered that the animals are systematic when preying on red colombus monkeys.

Specifically, the team discovered that the animals start eating the babies’ brains when they capture the animals.

The gruesome habit may be linked to the nutritional quality of the brain, according to the researchers – and early human ancestors may have followed a similar path. 

When chimpanzees hunt red colombus monkeys they eat the brains of the baby monkeys first, a new report explains. This could be because the brains have nutritional value. The brains of babies are easier to access than those of adults (file photo)

The researchers examined footage of chimps in Gombe National Park in Tanzania to learn about the ways in which the animals consume meat.

By examining videos of chimps, they discovered that the animals eat the brains of infants, adolescents and juveniles first.

This led Gilby to wonder why the animals ate certain body parts first, and he reached the conclusion it has to do with the nutritional value of certain body parts.

He told National Geographic: ‘We tend to just say meat is meat, but we know that the nutrient composition varies. The whole carcass is valuable but the brain is especially valuable.’

The reason chimps head straight for babies’ brains could have something to do with their accessibility: brains of adult colombus monkeys are not as easy to get to because predators would have to crack fully-formed skulls to get to them.

If a chimp were to try to kill an adult monkey they might not be able to get to its brains before a competing chimp snatched the prey from it.

This could explain why chimps at Gombe go for the torso first upon capturing an adult monkey.

Texas State University biological anthropologist Jill Pruetz told National Geographic: ‘[This] might be one of the first quantitative studies about how exactly a prey item is eaten by chimps.’


A new report from a team led by Arizona State University anthropologist Ian Gilby explains that chimps eat the brains of baby monkeys first when they hunt.

There are a number of reasons that explain why they have developed this practice.

One is that it could be easier for the animals to access babies’ brains since they do not have to crack fully-formed skulls to get to them.

A new report explains why chimpanzees eat the brains of baby red colombus monkeys before eating other body parts when they hunt the animals (file photo)

A new report explains why chimpanzees eat the brains of baby red colombus monkeys before eating other body parts when they hunt the animals (file photo)

Another reasoning for the chimps’ decision to eat the brains could come down to the fact that they contain fatty acids and have nutritional value.

However, researchers have not completely pinpointed the reason for the behavior.

For example, they do not understand why chimps’ eating habits vary from study site to study site.

At one site chimps give captured heads away at times, which puzzles scientists learning about their diets.

Pruetz studies chimpanzees in Senegal, and she said she has witnessed similar behavior there.

She has watched chimps eat the heads of bushbabies first.

One of the reasons the animals target the brains could be that brains are a source of fatty acids that support neurological development.

Pruetz said the tendency is linked to nutrition but that researchers still have questions about the practice.

But the researchers do believe that the habit, coming from a species that humans probably share a common ancestor with, likely speaks to human evolution.

Pruetz said: ‘One of the best ways we have of understanding early hominids is using chimps as a model. Getting the clearest picture of chimpanzee hunting can allow us to make predictions about how the earliest hominids may have behaved.’

Gilby said the new work suggests that the tendency might have been driven by a need to eat fatty foods.