The black rhinoceros, Diceros bicornis, is listed as Critically Endangered. Throughout most of the 20th century, the black rhino was the most numerous of the world's rhino species. Relentless hunting of the species and clearances of land for settlement and agriculture resulted in the population being reduced from a probable several hundred thousand at the start of the century, to less than 2,500 by the early 1990s.

The greater one-horned rhino, Rhinocerus unicornus, is considered to be Vulnerable. The IUCN's African Rhino Specialist Group has a policy of not releasing detailed information on the whereabouts of all rhino populations for security reasons.

The populations of all three species now are increasing slowly, according to the IUCN.

By 1977, all international commercial trade in rhinos and their products was prohibited under the Convention on International Trade in Endangered Species. However, following a continued increase in numbers, in 1994 the South African population of southern white rhino was downlisted to allow for trade in live animals to "approved and acceptable destinations" and for the continued export of hunting trophies. In 2004, Swaziland's southern white rhinos were similarly downlisted.

In September 2010, the British government placed restrictions on the export of antique rhino horn objects and trophies, concerned that these items were being auctioned off at high prices and exported for grinding down and sale as powdered horn in the Far East, fueling the rhino horn trade.

Minister for the Natural Environment and Fisheries Richard Benyon said, "I am extremely concerned about the increase in the number of rhinoceros horn products being sold through UK auction houses. We believe this is providing a financial incentive for poachers and encouraging the use of rhinoceros horns in Asian medicine."

"The government is committed to protecting endangered species, and in order to do this it has become necessary to take steps to refuse future applications for the export of rhinoceros horn," said Benyon.

Jones said, "We were pleased to see the UK take these steps, and urge other nations to do the same."

Care for the Wild International today called for immediate action to save rhino populations from extinction at the hands of poachers.

"We need better protection for the remaining rhino populations. More and better trained and equipped park staff are urgently required. Border security needs to be tightened up. Loopholes in national and international regulations need to be closed to prevent poachers posing as trophy hunters and exporting "trophy" horns for sale," Jones advised.

"Exports of live rhinos from South African ranches need to be stopped," he said. "Horn stockpiles that are currently in private hands need to be managed by governments in a transparent way, and preferably destroyed."

"Every effort needs to be made to reduce demand for rhino horn in China, Vietnam, and elsewhere in Asia," said Jones, "through engagement of the Traditional Medicine Community, and through education, awareness-raising and rigorous law enforcement."