A great ape native to tropical forests and savannas of West and Central Africa, sharing ~98.7% DNA identity with humans. Males weigh 40–60 kg, females 27–50 kg. They have black fur, bare dark faces, prominent brow ridges, and large ears. Chimpanzees are knuckle-walkers that also climb proficiently. They are omnivorous, eating fruits, leaves, insects, and occasionally hunting small mammals cooperatively. Famous for sophisticated tool use—using sticks to fish for termites, stones to crack nuts, and leaves as sponges. Social structure is a fission-fusion community of 20–150 individuals led by an alpha male, with complex alliances and politics. Communication involves diverse vocalizations (pant-hoots), gestures, and facial expressions. Females have a ~230-day gestation, producing one infant with a long inter-birth interval of ~5 years. They can live 40–50 years in the wild. Chimpanzees have been crucial in understanding human evolution, cognition, and disease. Their genome was sequenced in 2005. IUCN status: Endangered, threatened by habitat loss, poaching, and disease.