It's been used to make everything from jewelry to figurines, to piano keys, but it's also led to the decimation of some elephant species by poachers, people who illegally killed the animals for their ivory.
Hunting is now illegal in the parks but it's still a big problem for even the smallest in the group like this infant whose hand was caught in a poacher's snare.
Hippos are being killed by government soldiers, local militia and poachers, the World Wildlife Fund said. The meat is sold as food while teeth end up as part of the illegal ivory trade.