african aggressive animal ape apes appearance chimp chimpanzee common-chimpanzee dark dishevelled expression expressive face features great-ape hairy mammal pan-troglodytes primate prominent resting sitting strong territorial zoo adult arboreal Asian bearded female great apes highly intelligent intelligent mammals mature mother orang-utan pongo abelii primates red red-haired senior junior offspring orangutan playful playing young youngster agile climber climbing great-apes highly-intelligent pongo-abelii rope