Bonobos are quite possibly the most intelligent primates on Earth (other than us, of course!). The San Diego Zoo was one of the first zoos to exhibit these highly endangered primates. One characteristic bonobos are especially known for is their ability to get along: unlike humans or chimpanzees, they have never been observed killing one of their own kind. These clever apes are fun to watch. Their exhibit is dominated by giant rock outcroppings, and ropes and hammocks attached to bamboo sway poles, on which the playful bonobos nimbly climb or rest. Waterfalls and streams add to the African rain forest atmosphere. But the real show is the bonobos themselves—do they remind you of anyone? Did you know? Bonobos were described as a subspecies of chimpanzee in 1929 but identified as a separate species in 1933. They are still the least understood of the great apes.