MUCH of what we know about bonobos comes from observing animals in captivity. Famously characterised as peaceable and sex-loving, a darker and more complex picture emerges from studies in the wild. For example, far from being the "hippy chimp", bonobos hunt for meat, consuming monkeys without bothering to kill them first.
Yet we still know relatively little about one of our closest relatives. To document their behaviour in the wild, photographer Christian Ziegler travelled to the rainforest south of the Congo river, in the Democratic Republic of the Congo.
"I learned that when they looked at me as if I didn't belong, I just imitated what they were doing, grooming or eating, and they seemed fine," says Ziegler. "I ate lots of things that they ate, many of which were quite tasty." (Presumably, he is not referring to live monkeys.)
After four weeks, he got this shot. The troop had spent the morning foraging, including eating unripe fruit followed by orange clay to neutralise plant toxins. This teenage female has orange lips as a result of the clay. It is an image of relaxation, but bonobo numbers are in decline.
"Right now we can't be sure that they can be safeguarded," says Ziegler. "Huge parts of the Congo basin are empty, and primates and especially apes are targeted for bushmeat."
This article appeared in print under the headline "The flaming lips"