Two endangered rhinos have been critically injured and a third died after poachers in South Africa hunted the animals down and chopped off their horns.

Rhino horn—possession of which is banned under international law—is valued for use in traditional Asian medicine to treat cancer and other disorders, even though the horns—made of keratin like that in our fingernails and hair—have no actual medicinal value. Still, demand is so high that horns can fetch prices higher than gold. As a result, poachers have devastated rhino populations across Africa and Asia in the past decade, sending multiple species into extinction and threatening those that remain. At least 448 rhinos were killed by poachers in South Africa in 2011, up from 333 in 2010 and just 13 in 2007. At least 80 more have been killed in South Africa in the first two months of 2012.

Thanks to decades of conservation efforts, the southern white rhinoceros (Ceratotherium simum simum) is the most populous remaining rhino species on Earth, with approximately 17,000 animals in the wild, 93 percent of which live in South Africa.

The attack on the three white rhinos took place on Friday, March 2, at the privately owned Kariega Game Reserve in South Africa's Eastern Cape Province. Poachers darted the family with sedatives, then killed one of the animals and left the other two for dead after removing their horns.

One of the surviving animals, a male, suffered injuries to his leg when he was tranquilized and may need to be euthanized. "He sustained a serious amount of tissue damage to his left back leg," Kariega general manager Alan Weyer told Dispatchonline, saying the rhino fell on its leg during the attack. "That amount of tissue damage is not something that a veterinarian can fix. At the moment, he can walk but he is limping quite badly." According to the Saving Private Rhino page on Facebook, the rhino was treated with anti-inflammatory drugs and antibiotics on Saturday, the day after the attack. On Monday, the animal was treated for wounds on his face where its horn had been hacked off. The leg injury and resulting risk of infection is the biggest threat to the rhino's survival. Kariega veterinarian William Fowlds reported that "there are large areas of his left back leg that have little or no blood supply." In addition, his right eye is clouded over, limiting his vision, and he has not been observed eating or drinking since the attack.

The other surviving rhino, a female, was not located until early March 4, when she was found grazing near the site of the attack. The wounds on her body and head, although not immediately life-threatening, were quite severe. On Monday, Fowlds reported the heartbreaking details:

"Her body appears to be recovering well but her facial injuries are worse than they appear from a distance. There is an area 30 centimeters long and 15 centimeters wide of exposed hacked skull and gaping holes into the underlying sinuses. The infection has already set in and maggots have started in the crevices left behind by the panga [machete] lesions. We cut away as much dead tissue as possible but there is still an area of bony tissue that will need removing probably at a later stage. An application of medical tar will sort the maggots out but there is a long road ahead for this poor lady. Her fighting spirit is humbling to witness as her face depicts such utter shame on humanity. The whole team were deeply moved by this horrendous experience and the bravery if this soul."

It is extremely rare for rhinos to survive poaching attempts, as they usually bleed to death from their wounds. Another dehorned Kariega rhino was found in February. Its injuries were so severe that the animal had to be euthanized.

Sadly, the rising rhino death toll in South Africa is sometimes enabled by the very people who are supposed to protect the animals. All of the following incidents occurred in the past week in South Africa: four employees of Kruger National Park—the site of more than half of South Africa's rhino poaching—were arrested on charges connecting them with poaching; three veterinarians appeared in court in Johannesburg to face charges of distributing veterinary drugs often used to subdue rhinos in order to hack off their horns; a game ranger and two farmers were arrested after they cut the fence around Mkuze Falls Private Game Reserve, where they allegedly planned to target seven rhinos; and a former police officer was arrested for possession of two rhino horns.

According to the organization Saving Rhinos, LLC, conviction rates for rhino-related crimes is below 5 percent and crimes committed by white persons appear to receive lower punishments than those committed by persons of color.

On March 6 Kariega announced that the two injured rhinos have been named: "Our rangers have come up with two beautiful Xhosa names for the surviving Kariega rhinos. Our strong and willful female has been named Thandiswa, meaning tenacity and courage; and for our young male, Themba, the Xhosa word meaning hope." Xhosa is one of the official languages of South Africa. The Kariega Foundation has also set up a fund to help care for and rehabilitate the animals.