Dehorning must not be seen as a silver bullet, according to experts. (Photo supplied)
Dehorning rhinos can reduce poaching by as much as 78%, making it a significant and cost-effective conservation tool, a landmark international study has found.
The research, published in the prestigious journal Science, focused on 11 reserves in South Africa’s Greater Kruger region from 2017 to 2023 — a critical global stronghold that conserves about a quarter of all Africa’s rhinos.
The Greater Kruger, spanning Mpumalanga and Limpopo, includes the Kruger National Park and the private nature reserves around it, and is an umbrella for the various private game reserves that make up the unfenced protected wilderness that lies adjacent to the Kruger Park.
“Kruger National Park had a rhino population of about 12 000 back in 2012,” said the study’s lead author, Tim Kuiper, a senior lecturer in statistics and nature conservation at the Nelson Mandela University, based at the institution’s George campus.
“Today, we’re sitting at around probably below 2 000, so there’s been a drastic decline in the rhino population in the greater Kruger National Park and the surrounding private reserves.”
The project was a “mammoth effort” involving wide collaboration between reserve managers under the banner of the Greater Kruger Environmental Protection Foundation (GKEPF), and scientists from the University of Cape Town, Nelson Mandela University, Stellenbosch University and the University of Oxford in the UK. Other partners included South African National Parks the WWF-SA and the Rhino Recovery Fund.
They documented the poaching of 1 985 rhinos (about 6.5% of the population annually).
“The stakeholders got together to ask the question, ‘Why have rhinos declined so rapidly and what can we do about it and have the things we’ve been doing been working or not, and why,’” Kuiper said.
The GKEPF gathered seven years of data on rhino poaching levels, as well as on the various anti-poaching interventions — tracker dogs; air support, including helicopters and planes; detection cameras equipped with artificial intelligence; anti-poaching patrols and rapid-response teams.
“Then there were the more alternative approaches like dehorning to make the rhino less attractive to poachers. What we found across seven years in 11 reserves, including one reserve in Mozambique, was that dehorning was the single most effective intervention. Wherever it was implemented, it resulted in a drastic decline in poaching,” Kuiper said.
“Statistically-speaking, we had eight different sites and were able to isolate these massive reductions in poaching and link them to the wide-scale dehorning of rhinos.”
Dehorning rhinos to reduce incentives for poaching – with 2 284 rhinos dehorned across eight reserves – was found to achieve a 78% reduction in poaching, using just 1.2% of the overall rhino protection budget. This was based on a comparison between sites with and without dehorning as well as changes in poaching before and after dehorning.
Reserves under the study invested R1 billion in anti-poaching interventions from 2017 to 2021. Most of the investment focused on reactive law enforcement — rangers, tracker dogs, helicopters, access controls and detection cameras — helping to achieve over 700 poacher arrests. It costs R10 200 per dehorning operation.
“But we failed to find evidence that those arrests translated into less future poaching,” he pointed out. “So, on one level these interventions were successful but they did not result in the same level of reduction in poaching as dehorning did.”
There are key reasons for this, including corruption.
“The internal involvement of reserve staff with the criminal syndicates who are driving poaching means that these syndicates and the poachers can get around the interventions because they have information on where the rangers are going to be, where the rhinos are, where the cameras are [and] where the dogs are,” Kuiper said.
The region, too, suffers from a “great deal of socio-economic inequality”, he added. “There’s poverty, there’s poor government service delivery in those towns next to the Kruger National Park and what this means is that, even though poaching poses a high risk to the poacher, it seems that there is a large pool of motivated offenders willing to take that risk.
“And, the criminal syndicates take advantage of these community members, for example by offering to give them loans, and when they can’t pay back the loans, they say, ‘Well, here’s a gun. Help me with this rhino poaching operation.’
“It’s not often as simple as that but these criminal syndicates take advantage of the socio-economic vulnerability of both rangers and others in order to get that internal information.”
Finally, an ineffective criminal justice system means that arrested offenders often escape
punishment, according to evidence from studies on multiple-repeat offenders.
“The criminal justice system, the internal corruption and the socio-economic inequality are these massive system-level drivers that dampen the effectiveness of these security and technology interventions.
“In the worst case, these interventions may also isolate the people living around these reserves in terms of their involvement in conservation,” he said.
Kuiper cautioned that dehorning must not be seen as a silver bullet. “We did document over 100 dehorned rhinos being poached. The horn regrows, so in many of these cases, the horn had regrown quite a lot and the rhino was poached.
“This points to the need for regular dehorning but also points to the fact that syndicates are adapting and seem still to be willing to poach a rhino, even if there’s only 5cm to 10cm of horn left on the rhino. But, of all of the interventions, we analysed it [dehorning] led to drastic reductions in poaching.”
More recent evidence has emerged since the study concluded in 2023 suggesting that the poaching of dehorned rhinos is a growing challenge. Dehorning may also shift the focus of poachers to horned populations elsewhere, Kuiper noted.
A multi-faceted approach is necessary. “We need to look at wider systematic solutions addressing poverty, addressing socio-economic inequality, addressing the demand for rhino horn in consumer rates.”
Sharon Hausmann, the chief executive of the GKEPF, which led the initiative by convening manager workshops and gathering data for the evaluation, said: “The true value of this innovative study, conceived by GKEPF operational managers, lies in its collective critical thinking. Ensuring not only that operations are guided by science, but also that science is grounded in real experience from the frontline.”
Markus Hofmeyr of the Rhino Recovery Fund, said: “From a donor perspective, this study
has given excellent insight where conservation donor funding can be spent and where to avoid funding.”