High demand from Asia has driving rhino poaching to its highest level in more than a decade, according to a new report (PDF) by the by WWF, the International Union for the Conservation of Nature (IUCN) and Traffic. The report was presented last week at a meeting of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Rhino horns are valued in traditional Chinese medicine, where they are touted as aphrodisiacs and as a cure for a variety of diseases, including cancer.

According to the report, at least 162 rhinoceroses were illegally killed in South Africa and Zimbabwe in 2008. Another 62 have been poached during the first six months of 2009. The average during this period was 12.4 rhinos killed per month in those two countries alone, more than three times the average of 3.5 rhinos poached every month across all of Africa between 2000 and 2005 (a total of 252 rhinos during the six-year period).

In addition to poaching, the report found that horns collected as trophies during legal South African sports hunts have also found their way into the illegal market.

Historically, many poached rhino horns ended up in the Middle East, where they became ceremonial dagger handles. But Asian medicine, particularly in Vietnam, now appears to drive the illegal trade. According to the report, "illegal rhinoceros horn trade to destinations in Asia is driving this killing, with growing evidence of the ongoing involvement of Vietnamese, Chinese and Thai nationals in the illicit procurement and transport of rhinoceros horn out of Africa." The report blames organized crime for much of this activity.

Rhino populations in Africa have been rising, but this increase in poaching is a "major concern" according to the organizations, which have called for increased enforcement, better protection for wild rhinos and improved tracking of horns procured during legal trophy hunts.

The southern white rhinoceros (Ceratotherium simum simum) is listed as near threatened by the IUCN Red List of Endangered Species, with a population of around 17,000. The black rhinoceros (Diceros bicornis) is critically endangered, with a population near 4,000, up from 2,500 individuals 20 years ago.

Image: White rhinoceros, via Wikipedia