The Bili ape, also known as the Bondo mystery ape, is believed to be a type of chimpanzee. These apes are native to the Democratic Republic of Congo, and they typically live in such remote parts of the forest that biologists believe they have had very little contact with humans. These apes are very similar in appearance and behavior to the common chimpanzee, except that they are generally much larger, and have a skull crest similar to that of a gorilla. The typical Bili ape may weigh as much as 220 pounds (100 kilos) and may leave a footprint up to 13.6 inches (34 centimeters) long. Biologists have had few opportunities to study the Bili ape, but they believe it may be a more aggressive predator than the common chimpanzee.
Local legend has it that the Bili ape is capable of hunting and killing other large African predators, including leopards, lions, buffalo, and elephants. While scientists have not yet observed this hunting behavior, evidence suggests that the legends may be true. One scientist, Cleve Hicks, from the University of Amsterdam, and his research team were able to observe several of these apes feeding on a dead leopard. They did not observe the leopard's death, however, and have cautioned that the apes may have stumbled across its carcass after its death.
Unlike smaller common chimpanzees, however, the Bili ape often builds its nest on the ground. Researchers believe that this may be another indication of the ape's status as an aggressive predator. Chimpanzees normally build their nests in the branches of trees, since this typically offers them optimal protection from predators on the ground, such as leopards and lions. Some researchers surmise that the presence of Bili ape nests on the ground means that these animals are recognized as formidable predators in the animal kingdom, and therefore have less need to fear attacks by other predators in the night.
Scientists have not yet fully chronicled the habits and behavior of the Bili ape, since these creatures usually live far from any human habitation. They are considered a type of chimpanzee and are believed to behave in much the same way as other chimpanzees, though there are some variations in their behavior. Their use of tools, for instance, may be different from that of other apes, in that their favorite tools appear to be large rocks. Bili apes have been observed to use rocks to smash open termite and ant nests, shelled fruits, snails, and even turtles for food.