Although greatly reduced in number by settlers and sport hunters during the colonial era, the overwhelming cause of the rhino's decline during the past 50 years has been poaching. In the Far East, and in East Asian communities elsewhere, rhino horn is still prescribed as an ingredient in traditional remedies to reduce fever. With increasing wealth following World War II, medicines containing rhino horn - always rather expensive - became more affordable and demand rose steadily. By 1976, the price of "official" rhino horn, that is horn sold legally from government storerooms in rhino range states, was fetching US$80 a kilogram and being resold wholesale in eastern Asia for US$600 to US$750.

Rhino horn is also in demand in some Arab nations, where it is seen as a status symbol. With increasing wealth from oil revenues, the demand for curved daggers with handles carved from rhino horn has risen over the years. Yemen and Oman remain important destinations for illegally obtained rhino horn.

In addition to external demands, growing poverty in many African countries fuelled a vigorous trade in illegal wildlife products, particularly rhino horn and ivory. Newly independent African governments found themselves with growing human populations, diminishing financial resources, and an urgent need to place social development at the top of a long list of priorities. As a consequence, wildlife departments found themselves increasingly short of funds. The combination of diminishing resources, poor political support, and corruption sent morale and effectiveness plummeting. So it was that during the 1970s and 1980s many rhinos were poached by the very people employed to protect them.

While most of the profit from the illegal trade in wildlife products ends up in the pockets of a few traders and middlemen, even the small amounts earned by poachers are incentive enough to risk fines, imprisonment or death. Poachers will even cross international borders in search of rhinos. Sudanese poachers were responsible for wiping out the CAR's rhinos in the 1970s; Somalis were heavily involved with rhino and elephant poaching in Kenya; and members of South Africa's military forces plundered the wildlife resources of Mozambique and Angola. In the mid-1980s, Zimbabwe launched military-style operations in an attempt to stem the cross-border activities of Zambian-based poachers in the Zambezi Valley.

Civil unrest and the free flow of weapons in Africa have also had a significant impact on conservation efforts. Rhino populations in Angola, CAR, Chad, the Democratic Republic of Congo, Mozambique, Namibia, Rwanda, Somalia, Sudan, and Uganda have all suffered from the consequences of war and civil unrest during the past 30 years. Almost 70 per cent of northern white rhino were killed during the 1960s and 1970s as poaching went unchecked amid civil wars.

As the wave of poaching spread south from the Horn of Africa, populations of black rhino were decimated in Kenya and Tanzania. Gathering momentum as it went, the wave reached Zambia in the 1970s and 1980s and finally Zimbabwe, Botswana, and Namibia in the 1980s and early-1990s.