Conservationists have particularly worried about primates. The Congo is inhabited by several great ape species: the common chimpanzee (''Pan troglodytes''), the bonobo (''Pan paniscus''), the eastern gorilla (''Gorilla beringei''), and possibly the western gorilla (''Gorilla gorilla''). It is the only country in the world in which bonobos are found in the wild. Much concern has been raised about great ape extinction. Because of hunting and habitat destruction, the chimpanzee, the bonobo and the gorilla, each of whose populations once numbered in the millions, have now dwindled down to only about 200,000 gorillas, 100,000 chimpanzees and possibly only about 10,000 bonobos. Gorillas, chimpanzees, and bonobos are all classified as endangered by the World Conservation Union, as well as the okapi, which is also native to the area.