ConservationFor most of the 20th century the continental black rhino was the most numerous of all rhino species. Around 1900 there were probably several hundred thousand living in Africa. During the latter half of the 20th century their numbers were severely reduced from an estimated 70,000 in the late 1960s to only 10,000 to 15,000 in 1981. In the early 1990s the number dipped below 2,500, and in 2004 it was reported that only 2,410 black rhinos remained. According to the International Rhino Foundation, the total African population had recovered to 4,240 by 2008 (which suggests that the 2004 number was low). In 2002 only 10 West African rhinos remained in Cameroon, and in 2006 intensive surveys across its putative range failed to locate any, leading to fears that this subspecies was extinct. In 2011 the IUCN declared the Western black rhino extinct.
The only rhino that has recovered somewhat from the brink of extinction is the southern white whose numbers now are estimated around 14,500, up from fewer than 50 in the first decade of the 20th century.
The black rhinoceros had been pushed to the brink of extinction by illegal poaching for their horn, and to a lesser extent by loss of habitat. A major market for rhino horn has historically been in the Arab nations to make ornately carved handles for ceremonial daggers called jambiyas. Demand for these exploded in the 1970s causing the black rhinoceros population to decline 96% between 1970 and 1992. The horn is also used in traditional Chinese medicine, and is said by herbalists to be able to revive comatose patients, cure fevers, and aid male sexual stamina and fertility. The purported effectiveness of the use of rhino horn in treating any illness has not been confirmed by medical science. In June 2007, the first-ever documented case of the medicinal sale of black rhino horn in the United States (confirmed by genetic testing of the confiscated horn) occurred at a traditional Chinese medicine supply store in Portland, Oregon's Chinatown.