The bonobo's name probably comes from a misspelled shipping crate
One of humanity's two closest living relatives was named by accident. Bonobo is thought to be a garbled spelling of Bolobo, a Congo River town stencilled on a crate. And the old label pygmy chimpanzee was wrong too: it came from a single small skull, though bonobos are about the same size as chimps.
German anatomist Ernst Schwarz recognised the animal as distinct in 1928, working from a skull in Belgium's Tervuren Museum that had been filed as a young chimpanzee. He published in 1929, classing it as a chimp subspecies, and it was the undersized skull that earned the pygmy tag. The American anatomist Harold Coolidge raised it to full species in 1933. The name bonobo arrived in 1954, proposed by Eduard Paul Tratz and Heinz Heck, who also first described in detail how its behaviour differs from the chimpanzee's.
Geography probably made the species. Neither ape swims well, and the Congo River separates bonobos in the south from chimpanzees in the north. DNA points to a split roughly 890,000 to 860,000 years ago, perhaps as savannas spread; since the river is older than that, ancestral apes may have crossed on corridors that have since vanished. Genes show the two species mixed at least twice in the past 550,000 years. Bonobos also seem to have changed remarkably little in their skeleton and muscles, which makes them a useful stand-in for the last ancestor shared with humans.
Compared with chimps, bonobos have longer legs, narrower shoulders, pinker lips, darker faces and long head hair that falls in a parting. Males average about 45 kilograms and females 33. The first genome appeared in 2012, taken from a female at Leipzig Zoo, and differs from the chimpanzee's by about 0.4 percent; a high-quality reference genome followed in 2021.
Bonobos live only within a 500,000 square kilometre stretch of the Congo Basin in the Democratic Republic of the Congo, mostly eating fruit. Estimates put their numbers between 29,500 and 50,000, and they are listed as Endangered, with commercial poaching the biggest threat. Their shyness and regional instability mean relatively little fieldwork has been done in the wild.
Source: Bonobo
