We were fascinated to learn about a recent study that has identified a new chimpanzee culture in the Northern Democratic Republic of Congo using new tools researchers are describing as an “ant scoop” and a “fruit hammer.”
About half of the world’s remaining chimpanzees live there, yet until now researchers have known almost nothing about their behavior.
Primarily Primates is home to 35 chimpanzees, and care staff members work tirelessly to create opportunities for them to mimic wild behaviors.
In the study, researchers studied the insect-related tool technology of Bili-Uéré chimpanzees and discovered a new tool kit: long probes used to harvest driver ants; short probes used to extract ponerine ants and the arboreal nests of stingless bees; thin wands to dip for D. kohli ants, and stout digging sticks used to access underground stingless bee nests.
In addition, the researchers have documented an expanded percussive technology—or pounding activity—associated with food processing. In addition to pounding hard-shelled fruits against a firm surface (which is seen in other chimpanzee populations), the Northern Congo apes also pound open two kinds of termite mounds, a resource that chimpanzees in most other regions ignore. There is also evidence of pounding open of African giant snails and tortoises.
The researchers, however, found no evidence of termite “fishing,” despite the availability of termite mounds throughout the region and that other populations of chimpanzees “fish” at a number of other long-term research sites.
According to the study, overall chimpanzee behavior varies across tropical Africa in a way that does not always correspond to ecology: for instance, only West African chimpanzees, but no others, use stone and wooden hammers to crack nuts in a number of populations. Previously, several large-scale behavioral patterns in chimpanzees have been documented, including the use of clubs to pound open beehives in Central Africa and long tools to scoop up algae across multiple sites in West Africa.
The chimpanzees at PPI receive food related enrichment where they are challenged to use problem-solving skills to manipulate a variety of puzzle feeders in order to indulge in special treats. The different enrichment activities promote the animals’ natural instincts and behaviors. The animals enjoy using tools to “fish” peanut butter out of PVC pipes that simulate termite mounds. They love foraging for seeds, dried fruit and nuts scattered throughout their habitats.