Chimpanzees were once considered so plentiful - in the wild as well as in captivity - they did not need our protection. That situation has changed.
From the brochure:
CHIMPANZEES, Pan troglodytes (ENDANGERED), are found in the forests and woodlands of equatorial Africa. In addition to tool use, they are capable of planning a hunt or organizing an attack against their rivals. They are at risk because of the pet trade as well as the bush meat (hunting of wildlife for food) trade.
Chimpanzee graphic (banner) by Christina Ward