Chimpanzees have been observed cracking open the shells of tortoises and scooping out their flesh, in a first for biological science.
Researchers from the Max Planck Institute for Evolutionary Anthropology and the University of Osnabrück studied a group of chimps in Gabon for two years, closely watching their behaviour each day.
They discovered the animals had a taste for reptile flesh, which had previously been suspected but never before confirmed.
"They use a percussive technique that they normally employ to open hard-shelled fruits to gain access to [the] meat of an animal that is almost inaccessible for any other predator," primatologist Tobias Deschner said.
The tortoises were more likely to be captured in the dry season, with the chimps alerted to their prey's presence by a rustling of dry leaf litter.
Chimpanzees are known for using percussive technology — or bashing objects against other objects — when foraging for food.
They crack open nuts and hard-shelled fruit, also bashing into termite mounds and the skulls of monkeys to feast on their brains.
Chimps have also been known to prey on birds and insects, as well as at least 25 different mammal species, ranging from small rodents to juvenile bush pigs weighing as much as 20 kilograms.
Researchers described their observations in a study published in Scientific Reports this week, noting how the chimps readily shared their reptilian treats.
"Sometimes, younger animals or females were unable to crack open the tortoise on their own," lead author Simone Pika said in a statement.
"They then regularly handed the tortoise over to a stronger male who cracked the tortoise's shell open and shared the meat with all other individuals present."
Tortoise stash a sign of planning skills
Scientists also watched on as one of the chimps, a large male, was able to restrain himself from binging on entire reptile, keeping a shell "container" of leftovers for later.
He tucked the shell containing the uneaten meat into a fork in a tree before building a nest for the night.
The next day, he returned to finish off the tortoise for breakfast.
"This indicates that chimpanzees may plan for the future," Dr Pika said.
"The ability to plan for a future need, such as for instance hunger, has so far only been shown in non-human animals in experimental and/or captive settings.
"Many scholars still believe that future-oriented cognition is a uniquely human ability.
"Our findings thus suggest that even after decades of research, we have not yet grasped the full complexity of chimpanzees' intelligence and flexibility," Dr Pika said.
ABC
