A full moon is bad news for rhinos -- it lights up the bush, allowing poachers to move about easily without flashlights.
The front line of the rhino poaching war is the border between South Africa and Mozambique in Kruger National Park, where the original 150-kilometer fence between the two countries was dropped in 2002. Very poor Mozambicans can easily be coerced into crossing the border into South Africa to kill a rhino and bring back its horn. Killing a rhino has even become a rite of passage there, and poachers are now conspicuous about their newfound wealth. If a hapless rhino wanders across the border into Mozambique, its life expectancy turns into a few days. Of course, rhinos are at risk all over South Africa as well.
The criminal syndicates involved in rhino poaching and wildlife trafficking in general are very complicated and powerful. The individuals doing the poaching are at the very bottom of the chain, and the middlemen and millionaires who want the end product are facilitating and driving the entire process. These chains of eight-plus people make arrests very difficult: each level of the chain only has contact with the individual directly above and below him.
There are many strategies currently being used with various amounts of success to protect the world's remaining rhinos from being poached. In Botswana, a shoot-to-kill policy has been implemented for poachers, and it has been very successful. Of course, Botswana barely has any rhinos left at this point. This policy has not been applied in South Africa, however. Therefore, private owners and reserves have been forced to devise other techniques to protect their rhinos.
In South Africa, some reserves use a poison combined with a bright pink dye to deter poachers, along with advertising that the poison has been used. This "poison" is not deadly, but merely makes rhino horn unfit for human consumption. As a warning, the bright pink dye is also inserted into the horn and it spreads throughout the inside of the horn as an indication of the poison. The rhino has to be darted, and a small hole is drilled to introduce these substances, but the animal is ultimately not harmed and the hole closes up, making the dye and poison undetectable. Signs advertising the use of the poison in multiple languages are often posted every hundred meters along the fence as a deterrent, and this seems to have been successful at various reserves. When the rhino is darted to insert the poison and dye, microchips are frequently embedded in the horn as well.
A more extreme option is dehorning the animals. As rhino horn is made of keratin and grows continuously, much like human hair and nails, it grows back in about three years and dehorning doesn't harm the animals physically. Dehorning has some downsides, however: rhinos use their horns for many things, and a rhino without his or her horn would be at a disadvantage socially if fighting or even play-fighting with another rhino. Additionally, even a small nub of horn is valuable, and a poacher would kill a dehorned rhino for its growth plate and the small amount of horn underneath the skin. Another issue dehorning raises is what to do with the horn -- private stockpiles are often robbed. Thus, removing the horn from the rhino becomes a liability for the owner, and the rhino still is not guaranteed safety.
Despite all of these tactics and efforts, rhino poaching continues. These endeavors make a big difference, but they are ultimately just a Band-Aid over a deep, seeping laceration, and we need to make many changes to win this war.