Image copyright WWF Image caption A tranquilised rhino is dehorned by a researcher in Zimbabwe to make the animal less attractive to poachers

Figures from the South African government indicate that poaching for rhinoceros has increased substantially in the last year.

A record 668 rhinos were killed for their horns in 2012, up almost 50% on the number for 2011.

The majority of the animals were killed in the Kruger national park, the country's biggest wildlife reserve.

Rhinos are being illegally killed...all for the frivolous use of their horns as a hangover cure Sabri Zain, TRAFFIC

Experts say that growing demand for rhino horn in Asia is driving the slaughter.

South Africa is home to around three quarters of the world's rhinoceros population of around 28,000 animals. In 2007 a mere 13 animals were lost to poachers.

But since then the killing has increased substantially. It is being fuelled by the belief in countries like China and Vietnam that powdered rhino horn has medicinal powers and can impact diseases like cancer. Horns can sell for around $65,000 a kg.

Poaching crisis

The rich rewards have attracted criminal gangs who deploy a range of sophisticated technologies in their efforts to capture and dehorn the animals.

The South African government have attempted to fight back using soldiers and surveillance aircraft, but the numbers indicate they are losing the fight.

Image copyright WWF Image caption Rhino horn slices being sold in Japan

According to a recent report from the wildlife monitoring network, TRAFFIC, South Africa's rhinos are now facing a poaching crisis that will lead to a population decline.

"Rhinos are being illegally killed, their horns hacked off and the animals left to bleed to death," says Traffic's director of advocacy Sabri Zain, "all for the frivolous use of their horns as a hangover cure."

Five more rhinos have been killed since the start of this year according to the South African government.

But the country is not alone in facing a threat to its rare rhino population.

India is home to more that 2,200 rhinoceros which are found in the well-protected Kaziranga reserve.

However even the use of around 900 armed rangers and guards hasn't been able to stop the poachers. Last year across India, 18 animals were killed, up from ten in 2011.

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