Dehorning Rhinos in South Africa
A rhino is characterised by its horn. Some might say their huge size, immense power, thick legs, or prehistoric appearance is what they think of when they picture a rhino, but most would point to their horns. So why has there been a sudden increase in dehorning rhinos in South Africa over the past few years? The answer is simple: it’s the last hope we have to deter poachers.
Why Must We Dehorn Rhinos?
Rhino horn is similar in structure to horses hooves, cockatoo bills, and turtle beaks. Like our fingernails, a rhino’s horn is made up of calcium, melanin and keratin. However, the insatiable demand for rhino horn in many Asian countries has led to the tragic decline of rhinos around the world.
As a last resort, many conservationists and game reserves are turning towards the costly though necessary method of dehorning rhinos in an effort to make them ‘less valuable’ to poachers.
How is a Rhino's Horn Removed?
- Rhinos are usually darted from a helicopter, though sometimes they are tranquillised from the ground in smaller reserves and game farms.
- The horn is removed with precision—typically 7cm from the base of the front horn and 5cm from the base of the back horn.
- Under anaesthesia, the horn is cut off horizontally using a chainsaw or hand-saw, while the rhino’s eyes and ears are covered to minimise stress.
- The remaining stump is trimmed, smoothed, and covered with Stockholm tar to prevent cracking and drying.
The First Country to Dehorn Rhinos
Namibia was the first country to use dehorning as a solution to protect rhinos from poaching. Between 1989 and the early 1990s, dehorning, coupled with rapid improvements in security and funding for anti-poaching, was perceived by stakeholders to have contributed significantly to reducing poaching losses. In Namibia, not a single dehorned rhino was poached.
Is Dehorning Effective?
Despite dedicated efforts from conservation teams, there are numerous cases where dehorning rhinos has proved insufficient to prevent them from falling victim to poachers. For example, in Hwange National Park, Zimbabwe, during the early 1990s, the majority of de-horned rhinos were killed just 12-18 months after being dehorned. In Zimbabwe’s Save Valley Conservancy, six newly dehorned rhinos were poached in January-August 2011 (one rhino was killed within 24 hours and another within five days of being dehorned).
The Need for Publicity and Anti-Poaching Campaigns
For dehorning to be effective, it needs to be coupled with extensive anti-poaching security and monitoring efforts. With an absence of security, rhinos may continue to be poached regardless of whether they have been dehorned. It is also vital for game reserves and local governments to dehorn rhinos in conjunction with a publicity drive to ensure that poachers are aware that a reserve’s rhinos have been dehorned. If not, there may be a lag effect whereby poachers continue to target rhinos in the area. There is also the possibility that dehorning rhinos in one area simply transfers the risk to horned individuals in other areas.
Why do Poachers Continue to Target Dehorned Rhinos?
Unfortunately, the stub of horn left after the removal still holds some value. But this is not something that can be prevented. If the horn is cut too close to the germinal layer, it could damage the horn base and lead to deformed horn re-growth. Current dehorning is estimated to remove 90% and 93% of horn mass in male and female white rhinos respectively.
During dehorning practices, a stub of the horn remains, and, although poaching is made less profitable, the sad reality is that poachers will still kill for a horn stub due to its high value per gram. However, a new initiative could see scientists inject non-toxic radioactive isotopes into the horns of rhinoceroses, making their entire horn, from the base to tip, unfit for human consumption and invaluable to poachers.
Retaliation Against Game Reserves
It is thought that poachers may also kill dehorned rhinos out of vengeance. There are many reasons that poachers might still target hornless rhinos, but a recent study suggests that poachers killed dehorned rhinos to avoid tracking them again. Furthermore, if they’re moving through thick bush or are tracking the animals at night, poachers may not see if the rhino has an intact horn prior to shooting.
Do Rhino Horns Grow Back?
Yes, a rhino’s horn will grow back over time, with recent studies indicating that the re-growth of dehorned rhino horns appears faster than growth in non-dehorned rhinos.
How often should Rhinos be Dehorned?
With the current severe poaching threat, experts recommend that rhinos should ideally be dehorned every 12-24 months in order to be an effective deterrent.
Is Dehorning Dangerous for Rhinos?
Dehorning is an intrusive procedure and, like any immobilisation, there is a risk to the rhino during the operation. While all efforts are taken to reduce the risk, there are sometimes veterinary complications while the animal is under anaesthetic that may result in death. The more frequently the rhinos are immobilised, the greater the risk.
What is the Cost of Dehorning a Rhino?
In addition, dehorning is incredibly costly, due to the effort of finding the animals and the costs associated with the immobilisation process, especially if needed on a recurrent basis. The actual cost depends on several factors, but current published estimates for dehorning range from US $620 (Kruger National Park) per animal to US $1,000 (private land).
It is estimated that it would cost around US $5.8-8.8 million for a one-off dehorning of all the rhinos in Kruger National Park (in practice, one could never hope to dehorn 100% of the population: some will successfully hideaway and one should never dart a pregnant cow).
Do Rhinos Need Their Horns?
Can rhinos live without their horns?
Reassuringly, a 2022 study on the effect of dehorning black rhinos in Namibia found that dehorning didn’t have any effect on population productivity. The study found no evidence to suggest that the dehorned rhino population had any differences in age of first reproduction, inter-calving interval, birth sex ratios, calf survival, cause of death, or lifespan.
Further, dehorning has been shown to reduce fighting-related mortalities among black rhinos in Zimbabwe. However, dehorning may also decrease the value of rhinos, whether for photographic or hunting tourism or as a potential live sale.
What Happens to the Removed Horns?
This is a controversial topic. many conservationists argue about what should be done with the removed horns. The horns could be destroyed; however, they are more likely to be stockpiled by reserves and game farm owners awaiting the potential legalisation of the rhino horn trade. A particular issue is that the current permit system for possessing, transporting and storing horns is considered to be onerous, and presents a security risk through the leakage of information on the whereabouts of removed horns.
This risk is emphasised by the fact that at least 38 horn-related thefts had occurred by mid-2009, and many more have occurred since, including several armed robberies. In South Africa, there has been a substantial internal trade of rhino horn from natural mortalities and illegally dehorned rhinos and subsequent leakage of horns onto the international black market.
A Last Chance for Rhinos
Dehorning has its place in rhino conservation and, although not a stand-alone solution, recent successes demonstrate that, used alongside other methods, dehorning can be used as one tool to help protect rhinos. Due to the invasive nature of dehorning, it should only be considered as a last resort under conditions of severe poaching threat. For example, although dehorning is not routinely practised in Kenya, the remaining Northern white rhinos are routinely dehorned due to the exceptional conservation value of being the last remaining individuals of the subspecies.
What is a Rhino without its Horn?
The first priority for all rhino conservationists should be to ensure adequate anti-poaching monitoring and security (including intelligence-gathering) to protect rhino populations, and only then should dehorning be considered, for is a rhino really a rhino without its horn?
