On November 5, Chumlong Lemtongthai, a 43-year-old Thai national, put his tightly scrawled signature to a guilty plea that was submitted to a South African court. As Accused Number 1 in case 143/2011, he admitted to arranging the illegal hunting of 26 rhinoceroses and the export of their horns to a company in Laos. The plea ends on an unassuming note: "I humbly apologize to the court and the people of South Africa for my role in this matter. I appreciate that the emotions of all animal lovers in South Africa are running very high and that I was part of the problem."

"The problem" required no further explanation for the judge, nor would it for most of his countrymen. Asian buyers, many in China and Vietnam, now pay upward of $50,000 per kilogram for rhino horn, to which they ascribe various powerful healing properties.

An international ban on the trade of rhino horn has created skyrocketing demand on the black market, leading criminal poaching and smuggling gangs to descend on South Africa — home to most of the world's rhino — with horrific results.

In 2007 only 13 rhino were poached in the country, about the average annual number since 1990. In 2008, the number rose sharply to 83, in 2009, to 123, and so on. This year — which isn't over yet — 585 rhino have been illegally killed in South Africa.

Rhino poaching in South Africa Photograph: Graphic

Local news bulletins regularly report macabre discoveries of rhino carcasses with bloody holes carved into their snouts, deadly firefights between game rangers and heavily armed poachers deep in the bush, or the arrest of Asian "tourists" caught leaving the region with suitcases full of horn. Angry citizens have formed pressure groups to lobby government, raise money for rhino protection, and demonstrate noisily outside courthouses where suspected rhino criminals are on trial. That's what they were doing when an impassive, shaven-headed Lemtongthai stood in the dock to receive the strictest sentence ever imposed in South Africa for wildlife crime: Framing the rhino as a symbol of Africa and poaching as an affront to African pride, Judge Prince Manyathi sentenced him to 40 years.

Conservationists were elated, some calling it the sort of deterrent that was required to put an end to the carnage. But their joy didn't last long; a week later, 11 rhino were found on a single day at two private ranches northwest of Johannesburg. Investigators arrested suspects in a poor neighborhood nearby — among them a game ranger — as a newly orphaned baby rhino, found wandering alone in the bush, was taken to an animal sanctuary.

Although poaching has recently increased in other countries where rhinos live, South Africa is the epicenter of the epidemic because it is home to 75 percent of the world's rhino, including 93 percent of by far the most numerous type, the southern white rhino. There are over 18,000 southern whites and about 2,000 black rhino within its borders. (Poachers favor white rhino because they're typically less aggressive than black and often carry bigger horns.)

A badly injured white rhino lies in a hollow after poachers sawed off its horn on Aquila Game Reserve in Touws River, some 180 Km North of Cape Town, on August 22, 2011. Photograph: Rodger Bosch/AFP/Getty Images

In the past, rhino were typically killed by impoverished local people using cheap firearms provided by black market middlemen. Although this kind of poaching is still common, increased security around rhino and the increased profits flowing from the horn trade have resulted in the emergence of more sophisticated criminal networks.

Smuggling gangs now recruit "triggermen" with military backgrounds equipped with silenced rifles and night vision equipment. Small helicopters, flying below air traffic control radar, are used to get poachers into and horn out of protected areas quickly. Wildlife veterinarians are bribed to provide locations of unprotected rhino or stocks of M99, a powerful drug used to sedate the animals for research.

Some well-resourced triggermen bring rhino down with darts containing M99 and then cut the horns from their faces with machetes or chainsaws while they are sedated but still alive. Even though a rhino that is injured like this will usually bleed to death within a day, the fact that it does not die immediately gives poachers more getaway time — game rangers have learned to look for circling vultures to alert them to freshly-killed animals, and a live rhino, even if mortally wounded, will not attract a kettle of scavenging birds.

Many others, including Chumlong Lemtongthai, have abused the system governing legal rhino trophy hunts to get past the international ban on horn trading currently in force under the Convention on International Trade in Endangered Species (CITES). Since 1968, South Africa has sold a small quota of expensive hunting permits, covering less than 1 percent of the white rhino population per year, to foreign trophy hunters. The millions of dollars raised from these hunts has benefited game ranchers and expanded land under conservation. The permits are granted on condition that the hunter in whose name they are granted fires the first shot at the animal, and that horns are exported to the hunter's home address fully mounted by a taxidermist, never to be sold.

Lemtongthai applied for multiple hunting permits in the names of Thai sex workers, who he paid to travel to a game ranch and pose, trophy hunter-style, with rhinos that had been shot by his South African accomplices. The horns then traveled from South Africa to southeast Asia as legal trophies, with official papers to "prove" it.

An young boys runs out a traditional medicine shop in Lan Ong street which sells grinding plates for rhino horns (on self wrapped in white paper) in downtown Hanoi on April 24, 2012 . From terminal cancer to strokes, rhino horn is seen as a miracle cure-all in Vietnam -- an expensive, medically unproven and illegal obsession that experts say is devastating global pachyderm populations. Photograph: Str/AFP/Getty Images

South Africa's rhino populations are still rising despite the poachers' onslaught. Rhino breed well under natural conditions, and about 1,400 southern whites were likely born last year. But this is little comfort to conservationists: A wave of poaching between 1970 and the late 1980s cut the African continent's black rhino population by an estimated 94 percent, from more than 70,000 down to only 3,800. Two rhino subspecies have recently been declared extinct due to poaching, the western subspecies of black rhino and the Vietnamese subspecies of Javan rhino. The northern white rhino may be the next to vanish forever as only seven animals of this type are known to remain, all in captivity; the last wild population, in the Democratic Republic of Congo, was wiped out by 2008. Assuming that current rates of illegal killing are maintained, South Africa's rhino population will begin to decline in 2016, according to a government researcher.

In South Africa, the first response to the escalation in poaching has been increased direct protection for the animals themselves. Game rangers have had their arms upgraded to take on the poaching gangs, and the military, operating under an unofficial shoot-to-kill policy, has been brought into Kruger National Park, where hundreds of rhino have been lost. Private game ranchers, who control a quarter of South Africa's rhino, have installed advanced intruder detection equipment and employed new security teams, many of which are run by ex-Iraq and Afghan war "security contractors"; some owners are now trying out drones to patrol their land.

Many rhino owners have resorted to dehorning – shortening their animals' horns — to make them less attractive targets. A rhino horn is made up largely of keratin, the protein in human hair and fingernails, and is similar to a horse's hoof. If it's cut off carefully, without harming the sensitive base, it will re-grow in a few years. Some biologists don't like this approach — a rhino's horn is, after all, its means of defense — and poachers will sometimes kill a rhino for the short stump of horn that remains. But many owners claim it's been effective in deterring the triggermen. Others douse horns in unsightly, brightly-colored pesticide.

Increased poaching means substantially increased cost and risk to rhino owners. Maintaining a basic, armed, around-the-clock two-person private security team costs about $11,000 per month. Government spending on rhino protection has not been quantified, but it possibly run to tens of millions of dollars. In 2011, 26 poachers were documented killed in firefights with authorities, and there's every sign that more will die in 2012.

Rhino horn can fetch £50,000 a kilo. Photograph: Roberto Schmidt/AFP/Getty Images

John Hume is South Africa's largest private rhino owner, with more than 800 animals. He's a leading proponent of legalizing the horn trade, reasoning that Asian buyers aren't interested in rhinos, just their horns. So why not just periodically cut off their horns, leave the animals alive, and allow conservation to profit handsomely in the process? Hume's proposal is appealing, but things aren't quite so simple. Trade would have to be carefully regulated, and South African government agencies are often ineffective and corrupt (evidenced the number of police and national parks employees arrested for poaching). Key governments in Asia — China and Vietnam, in particular — are seen by many to be dragging their feet in taking decisive action to enforce existing CITES regulations, and it's not clear that they'd be willing or able to control a formal market in horn.

As with other contraband, hard numbers on the illegal horn trade are elusive, and it's not known if a legal industry could supply enough horn to reduce black market prices enough to disincentivize poachers. One estimate is that between 2.5 and 3.5 tons of rhino horn leaves South Africa every year, the product of poaching, the theft of display-mounted horns from museums, and "pseudohunts" like the one Lemtongthai conducted with the Thai sex workers.

The legalization debate would not be happening if there was an effective way of reducing demand among buyers. Conservationists disagree on why demand and poaching have risen so sharply since 2007, which makes formulating and coordinating an effective demand reduction strategy extremely challenging. Some say the recent rush for rhino horn emanates from Vietnam, where, a few years ago, rumors circulated that a prominent politician had been cured of cancer by consuming it. Many Vietnamese researchers and journalists say that sprinkling powdered rhino horn on food, snorting it like cocaine or using it as a hangover remedy has become fashionable way of showing status among the nouveaux riches. Staff at the Vietnamese Embassy in Pretoria have been found in possession of horn and even filmed buying it by a South African TV crew in 2008.

Others contend that increased demand in China is the main reason for the poaching epidemic. Rhino horn has long been part of the pharmacopoeia of traditional Chinese medicine, which ascribes fever- and inflammation-reducing qualities to it. But China banned internal trade in rhino horn in the early 1990s and removed it from the official list of traditional medications under pressure from conservationists. At least one influential researcher theorizes that horn became progressively harder to buy after the domestic trade ban, and dealers' stockpiles ran down, making what little horn remained in circulation increasingly expensive and fueling the expansion of poaching operations in Africa.

Other conservationists and researchers point to a 2008 report written by Jia Quin, a high-profile traditional Chinese medicine researcher, proposing the "sustainable utilization" of rhino horn and its re-legalization for medical use. Journalists have discovered that Jia is employed by Longhui, a subsidiary of a large Chinese firm called the Hawk Group, which is mainly a weapons manufacturer. Longhui has set up at least two rhino farms in China stocked with dozens of white rhino imported from South Africa. Longhui is controlled by powerful Communist Party politicians and has a clear interest in promoting the consumption of horn at the highest prices possible.

This high-profile push to promote horn consumption has many conservationists deeply worried. Some feel there will ultimately be no option but to legalize some form of horn trade to reduce poaching pressure. This will split Africa's conservation community, many of whom feel that any legal trade will become a cover for illegal trade and that selling rhino horn as a valuable commodity is a tacit acknowledgment that it is in fact a useful medicine — exactly the opposite message than environmental groups have been trying to send.

Solutions to the rhino poaching problem will likely be complex and will test the resolve of conservationists and governments around the world. These magnificent, primeval beasts may only survive as semi-domesticated animals with defaced horns, under electronic monitoring and guarded around the clock.