The South African government has proposed that a legal trade of rhino horn be established, arguing that this could reduce poaching and prevent the extinction of this species. In March 2013, some researchers suggested that the only way to reduce poaching would be to establish a regulated trade based on humane and renewable harvesting from live rhinos. The World Wildlife Fund opposes legalization of the horn trade, as it may increase demand, while IFAW released a report by EcoLarge, suggesting that more thorough knowledge of economic factors is required to justify the pro-trade option. Conservation According to the World Wide Fund for Nature, conservation of African rhinoceroses as consumers of large amounts of vegetation is crucial to maintaining the shape of the African landscape and the natural resources of local communities. Ways to prevent poaching Horn removal To prevent poaching, in certain areas, rhinos have been tranquillized and their horns removed. Armed park rangers, particularly in South Africa, are also working on the front lines to combat poaching, sometimes killing poachers who are caught in the act. A 2012 spike in rhino killings increased concerns about the future of the species. Horn poisoning In 2011, the Rhino Rescue Project began a horn-trade control method consisting of infusing the horns of living rhinos with a mixture of a pink dye and an acaricide (to kill ticks) which is safe for rhinos but toxic to humans. The procedure also includes inserting three RFID identification chips and taking DNA samples. Because of the fibrous nature of rhino horn, the pressurized dye infuses the interior of the horn but does not color the surface or affect rhino behavior. Depending on the quantity of horn a person consumes, experts believe the acaricide would cause nausea, stomach-ache, and diarrhea, and possibly convulsions. It would not be fatal—the primary deterrent is the knowledge that the treatment has been applied, communicated by signs posted at the refuges. The original idea grew out of research into the horn as a reservoir for one-time tick treatments, and experts selected an acaricide they think is safe for the rhino, oxpeckers, vultures, and other animals in the preserve's ecosystem. Proponents claim that the dye cannot be removed from the horns, and remains visible on x-ray scanners even when the horn is ground to a fine powder. The UK charity organization Save the Rhino has criticized horn poisoning on moral and practical grounds.