The western black rhinoceros (Diceros bicornis longipes) emerged some seven or eight million years ago, as one of the sub-species of the black rhino. It used to be distributed widely throughout the savannah of central western Africa, but its numbers began to drop sharply once humans decided to hunt the creatures for sport and to harvest their horns, which were believed to have pharmacological uses, including as an aphrodisiac.
For much of the 20th century, black rhino numbers were among the highest of all rhino species, with some 850,000 individuals. By 1960, though, those numbers dropped to a mere 100,000 as the rhinos’ habitats were cleared for land settlement and agriculture, and as the creatures themselves were hunted without mercy for their valuable horns. By 1995, those meager numbers had dropped by a further 98%, at which point, there were fewer than 2,500 across all of Africa. The western black rhino, whose remaining numbers were in Cameroon, entered into conservation, but it was too little, too late to stop those who had far more resources and incentive to kill these animals than those tasked with protecting them.