Why Neanderthals turned to cannibalism

A rapid period of warming more than 120,000 years ago drove Neanderthals in the south of France to eat six of their own (cannibalism), new research suggests.

The study, by French researchers Alban Defleur and Emmanuel Desclaux and published in the Journal of Archaeological Science paints a bleak picture of life for Neanderthals living during the last interglacial period.

In the 1990s, the remains of six Neanderthals – two adults, two adolescents and two children – were found in a small cave at Baume Moula-Guercy in the Rhône valley in southern France. 

The bones bear many of the hallmarks of cannibalism: cut marks made by stone tools, complete dismemberment of the individuals, and finger bones that look as if they’ve been gnawed by Neanderthal teeth, rather than by other carnivores.

Remains from other sites in Croatia, Spain and Belgium also show evidence of cannibalism. But in each case, there has been a lack of evidence to answer the question of why the Neanderthals engaged in the practice. Was it for nourishment or cultural ritual?

“Cannibalism is always a contentious thing, because we find it quite revolting,” says archaeologist Michelle Langley from Griffith University in Australia, who was not involved in the study.

The site at Baume Moula-Guercy seems to offer some clues.

The Neanderthal remains lie within a 40-centimetre-thick layer of the cave floor that corresponds to the last interglacial period. During this time – which lasted from 128,000 to 114,000 years ago – temperatures were one or two degrees Celsius higher than they are today, and several degrees higher than the periods preceding and following it.

Sifting through animal remains encased in layers of the cave floor, Defleur and Desclaux have reconstructed details of the animals that inhabited the region before, during and after the last interglacial period.

What they found was evidence of a rapid change in climate that drastically altered the environment of the Rhône Valley.

Before and after the warming, remains from reindeer and woolly mammoths are found, accompanied by smaller mice and lemmings. During the warmer period when the Neanderthals lived, the area was devoid of large mammals, instead inhabited by rodents and tortoises and snakes that migrated up from the Mediterranean.

“The change of climate from the glacial period to the last interglacial was very abrupt,” says Desclaux.

“We’re not [talking] in terms of geological scale, but more a human scale,” he says. “Maybe within a few generations, the landscape totally changed.” 

Open grasslands gave way to temperate forests and the Neanderthals, accustomed to hunting large prey such as bison and mammoth, apparently struggled with this rapid change. 

Analysis of tooth enamel from the Baume Moula-Guercy remains revealed stress lines typical of periods of stress, such as illness or malnutrition.

It’s likely, says Desclaux, that the individuals were consumed during a short period of time, prompted by a desperation to survive on the part of their devourers.

Neanderthals wouldn’t have made good food as part of a regular diet, because they aren’t as rich in calories as other animals, such as deer. There also were only a few hundred of the hominins inhabiting western Europe at the time, so hunting them would have been out of the question.

“For the first time, they have proper evidence that shows they were in desperate times, and they were doing what they need to do to survive,” says Langley. “They weren’t doing anything different to what modern humans would do in the same situation” 

Episodes of modern-day cannibalism during World War II or following the crash of Uruguayan Air Force Flight 571 in 1972 are well documented.

Nonetheless, this new evidence of what likely occurred in the Rhône Valley doesn’t rule out cannibalism for cultural or ritualistic purposes by other Neanderthals, says Desclaux.

“There have been cases of cultural cannibalism, but in this particular case that does not seem to be the case,” he says.