There are only 5,000 black rhinos left in the wild. Unfortunately, the horns of this species are worth a lot of money, and they are used in Chinese medicine and as dagger handles in Yemen. Black rhinos are only found in South Africa, Namibia, Kenya, Zimbabwe and Tanzania.

Also, there has been a significant decline in genetic diversity among black rhinos, as 44 of 64 genetic lineages no longer exist. Researchers say the future is "bleak", unless the conservation of genetically distinct populations is given priority.