The study, titled “Dehorning reduces rhino poaching”, is based on the analysis of data across 11 reserves in the Greater Kruger region of South Africa between 2017 and 2023.
Poaching for their horn is a major threat to the world’s five rhino species.
The project was a collaboration between reserve managers under the banner of the Greater Kruger Environmental Protection Foundation (GKEPF), and scientists from the University of Cape Town (UCT), Nelson Mandela University, University of Stellenbosch and the University of Oxford. Other partners included South African National Parks, the World Wildlife Fund South Africa, and the Rhino Recovery Fund.
Lead author, Dr Tim Kuiper of Nelson Mandela University, based at the institution’s George Campus, said, “We documented the poaching of 1 985 rhinos (about 6.5% of the population annually) across 11 Greater Kruger reserves over seven years.
This landscape is a critical global stronghold that conserves around 25% of all Africa’s rhinos.”
Dr Tim Kuiper
The Greater Kruger spans the Mpumalanga and Limpopo provinces of South Africa. It includes the Kruger National Park and the private nature reserves around it.
It is an umbrella for the various private game reserves that make up the unfenced protected wilderness that lies adjacent to the Kruger Park. The area spans 2-million hectares and borders Mozambique along its entire eastern boundary.
Dr Kuiper added, “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 comparison between sites with and without dehorning as well as changes in poaching before and after dehorning.
The study did, however, show that some poaching of dehorned rhinos for horn stumps and regrowth continued. While more recent evidence (2024-2025), emerging since the study concluded in 2023 suggests that this is a growing challenge.
“Dehorning may also shift the focus of poachers to horned populations elsewhere,” said Dr Kuiper.
Reserves under study invested $74-million (R1-billion) in anti-poaching interventions from 2017-2021. Most of the investment focused on reactive law enforcement — rangers, tracking dogs, helicopters, access controls and detection cameras — helping achieve over 700 poacher arrests. Yet, the authors found no statistical evidence that these interventions significantly reduced poaching. It costs $570 (R10 200) per dehorning operation.
Interventions that work to aid poacher detection and arrest, while a necessary element of the anti-poaching toolkit, are compromised by systemic factors, such as local poverty (driving people to take risks) and corruption (offering a way around interventions, as this recent hard-hitting report highlights).
“Finally, ineffective criminal justice systems mean that arrested offenders often escape punishment, with evidence from our study area of multiple repeat offenders,” said Dr Kuiper.
In a shining example of science-policy collaboration, this project was first conceived by reserve managers at the frontline of rhino conservation, who recognised the need to critically evaluate their investments into anti-poaching interventions – from tracking dogs to AI cameras. GKEPF led the initiative by convening manager workshops and gathering data for the evaluation.
Sharon Haussmann CEO of GKEPF, was the intermediary between the managers and scientists. She 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.”
Dr Markus Hofmeyr of the Rhino Recovery Fund, added: “From a donor perspective, this study has given excellent insight where conservation donor funding can be spent and where to avoid funding.”
The research results present an opportunity for government, funders, the private sector and NGOs to reassess their strategic approaches to wildlife crime in general and rhino poaching in particular.
Professor E.J. Milner-Gulland of the University of Oxford said: “This collaboration is a brilliant example of how the effectiveness of conservation interventions can be assessed quantitatively, even in challenging and complex situations, and how important the participation of on-the-ground practitioners is in initiating, and interpreting, such research.”
UCT Professor Res Altwegg, who supervised the statistical analysis, highlighted the importance of this publication: “It’s important to check that our conservation interventions work as intended, and keep working that way. For me, this project has again highlighted the value of collecting detailed data, both on the interventions that were applied and the outcome. It’s such data that makes robust quantitative analyses possible.”
Link to video interview with Dr Tim Kuiper
Link to rhino photos and video for media
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Black rhino 1-4 – General photos of black rhino in the Greater Kruger region. All dehorned and showing some horn regrowth. Credit: Dr Tim Kuiper).
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Dehorning operation – Greater Kruger region - white rhino being dehorned. Credit: Greater Kruger Environmental Protection Foundation
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Dehorned white rhino mother and calf - two photos - Greater Kruger region. Credit: Dr Tim Kuiper
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Horned white rhino mother and calf - one photo - Undisclosed South African reserve (Credit all photos: Tim Kuiper).
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Horned white rhino - three photos - Undisclosed South African reserve (Credit all photos: Dr Tim Kuiper).
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Video - horned white rhino - Greater Kruger reserve (Credit: Dr Tim Kuiper).