1 MARCH 2013 VOL 339 SCIENCE www.sciencemag.org 1038 POLICYFORUM A frica’s western black rhino Diceros bicornis longipes was declared extinct by the International Union for the Conservation of Nature (IUCN) in 2011. Africa’s other rhino populations are also under siege. South Africa is home to more than 90% of the world’s 20,000 white rhino Ceratotherium simum, and 40% (more than 80% together with its neighbor Namibia), of the 5000 remaining black rhino ( 1– 3). Yet, poaching in South Africa has, on average, more than doubled each year over the past 5 years (see the chart). If poaching continues to accelerate, Africa’s remaining rhino populations may become extinct in the wild within 20 years ( 4, 5). Because of the CITES (Convention on the Trade of Endangered Species) ban on the trade of rhino horn, in place since 1977, demand can only be met through the ille- gal market, which primarily relies on the killing of rhinos by poachers for their horns ( 6). The ban is failing because it artificially restricts sup- ply in the face of persistent and growing demand ( 4, 7). The only remaining option is a carefully regulated legal trade based on the humane and renewable harvesting of horn from live white rhinos. Provincial conservation agencies in South Africa and southern Afri- can rhino management groups have asked the South African gov- ernment to put forward a proposal for regulated international trade in rhino horn at the 16th CITES Conference of the Parties (COP- 16), held 3 to 14 March 2013. Why the Trade Ban Has Failed Skyrocketing poaching levels are driven by tremendous growth in the retail price of rhino horn, from around $4,700 per kilogram in 1993 ( 8) to around $65,000 per kilogram in 2012 ( 9). Rhino horn is now worth more, per unit weight, than gold, dia- monds, or cocaine. Robberies of horns from museum specimens across Europe have taken place ( 10). Even dehorning rhinos to reduce the incentive to poach has proven ineffective without the provision of additional security, because of the value of the remaining horn stubs ( 11). Rhino horn is used for dagger handles in Yemen and has been used in Chinese tradi- tional medicine for millennia as a presumed cure for a wide range of ailments ( 10). Rapid economic growth in east and southeast Asia is assumed to be the primary factor driving the increased demand for horn ( 12). The tre- mendous financial rewards have led poachers to use increasingly sophisticated technolo- gies, including helicopters and immobiliza- tion darts. The protection of rhinos has there- fore become increasingly expensive not only in financial terms but in human lives ( 13). The increased militarization of rhino protection has resulted in a reallocation of conservation resources and is adversely affecting other con- servation actions ( 14, 15). Moreover, higher levels of militarized enforcement of a trade ban with harsher pen- alties may only serve to drive up prices fur- ther because supply is restricted in the face of inelastic and growing demand ( 4). This will create more profitable opportunities for crime syndicates and increase the incen- tives for poachers, as has been demonstrated in attempts to ban or control alcohol, illicit drugs, and other wildlife products ( 16– 18). Stronger enforcement efforts will be further hampered by the cooption of corruptible gov- ernment officials by crime syndicates in a very lucrative illegal trade ( 17, 19). Further- more, as wildlife products, such as rhino horn, become rarer, their prices soar, which pushes them ever further into an economic supply- and-demand extinction vortex ( 10, 17, 20). Humane, Renewable Harvest and Legal Trade Rhino horn is composed entirely of keratin and regrows when cut. Sedating a rhino to shave its horn can be done for as little as $20. The annual horn production of one white rhino averages 0.9 kg per year ( 11). The current speculative estimates of the demand for horn based on the illegal supply ( 21) could there- fore be met by the 5000 white rhinos on pri- vate conservation land in South Africa alone. The natural death rate of rhinos of 2.6% would also provide hundreds of horns annually. The income generated for conserva- tion through a legal trade in rhino horn, accounting for the costs of dehorning and management, is substantial ( 4). In addition, with current technology, the risks to rhinos from dehorning are mini- mal, and there is limited evidence of significant behavioral change following dehorning ( 11). A legal trade could simultaneously sup- ply horns, fund rhino protection, and provide an incentive for their sustainable use and long-term sur- vival. The trade in crocodile skin is an example of how a legal market has reduced poaching pressure on wild populations ( 22). Evidence from studies of other wildlife products [e.g., ( 23– 28)] suggests that a legal trade can reduce the incentive for poaching if: (i) regu- lators can prevent the laundering of a threaten- ing level of illegal supply under the cover of a legal trade; (ii) the legal supply can deliver the product (horn) more easily, reliably, and cost-effectively than the illegal trade; (iii) the demand does not escalate to dangerous levels as the stigma associated with the illegality of the product is removed; and (iv) legally har- vested horns from live animals can substitute for horns obtained from wild, poached animals. A highly regulated legal trade based on the renewable cropping of horns from rhinos is Legal Trade of Africa’s Rhino Horns CONSERVATION Duan Biggs, 1 * Franck Courchamp, 2 Rowan Martin, 3 Hugh P. Possingham 1 A trade ban limits supply, therefore raising prices and driving black market poaching. *Author for correspondence. E-mail: ancientantwren@ gmail.com 1 Australian Research Council Centre of Excellence for Envi- ronmental Decisions, Centre for Biodiversity and Con- servation Science, University of Queensland, Brisbane, Queensland 4072, Australia. 2 Ecologie, Systematique et Evo- lution, Universite Paris-Sud, UMR CNRS 8079, Orsay, France. 3 Independent Consultant, Harare, 00263, Zimbabwe. 700 600 500 400 300 200 100 0 2000 7 6 25 22 10 13 24 13 83 122 333 448 668 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Year Rhino poached Annual rhino poaching in South Africa since 2000. Data from ( 2, 3). Published by AAAS