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9th June 2025
4 minutes read
This blog was originally published at biology.ox.ac.uk
University of Oxford researchers have contributed to an international study which found that dehorning rhinos resulted in a drastic reduction in poaching of these endangered animals.
The study analysed data from 11 reserves in the Greater Kruger region of South Africa between 2017 and 2023. This landscape is a critical global stronghold that conserves around 25% of all Africa’s rhinos. During the seven year period, 1,985 rhinos (about 6.5% of the Greater Kruger area population annually) were poached for their horns.
Lead author, Dr Tim Kuiper of Nelson Mandela University (George campus) said:
“Dehorning rhinos to reduce incentives for poaching (2,284 rhinos were 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.
Image: Tim Kuiper
The study did show, however, that some poaching of dehorned rhinos for horn stumps and regrowth continued, while more recent evidence (2024-2025) since the conclusion of the study in 2023 suggests this is a growing challenge. Dehorning may also shift the focus of poachers to horned populations elsewhere.
Professor Dame E.J. Milner-Gulland, Professor of Biodiversity supported the study through providing expert advice on bioeconomics, impact evaluation and wider assessing the conservation context of the work. She said:
“This study has important implications, not just for rhino management, but also more broadly for conservationists planning and implementing interventions. It also suggests that it’s worth thinking of ways to reduce the expected profitability of poaching (in this case through dehorning), rather than only focusing on increasing the expected risks and costs.”
Reserves included in the study’s assessment 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.
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. Ineffective criminal justice systems can also mean that arrested offenders often escape punishment.
Image: Tim 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). The Greater Kruger Environmental Protection Foundation (GKEPF) led the initiative by convening manager workshops and gathering data for the evaluation.
Professor Milner-Gulland added:
“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.”
Sharon Hausmann, 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.”
The research results present an opportunity for government, funders, the private sector and NGOs to re-reassess their strategic approaches to wildlife crime in general and rhino poaching in particular.
The project was a collaboration between reserve managers under the banner of the GKEPF and scientists from the University of Oxford, the University of Cape Town (UCT), Nelson Mandela University, and the University of Stellenbosch. Other partners included South African National Parks, the World Wildlife Fund South Africa, and the Rhino Recovery Fund.
To read more about this research, published in Science, visit: doi.org/10.1126/science.ado7490
Author
E.J. Milner-Gulland is Tasso Leventis Professor of Biodiversity at the University of Oxford. Previously she was Professor of Conservation Science at Imperial College London, and she has also held lectureships in Resource Economics and Mathematical Ecology. Her PhD, at Imperial College London, was on the wildlife trade, with a focus on ivory, rhino horn and saiga antelopes. Her research group, the Interdisciplinary Centre for Conservation Science, undertakes a wide range of research, outreach and engagement projects, on five continents and in both marine and terrestrial settings. These include developing and applying methods for understanding, predicting, and influencing human behaviour in the context of local resource use in developing countries, and working with businesses to improve their environmental and social sustainability. Her team also works on controlling the illegal trade in wildlife and on designing, monitoring and evaluating conservation interventions in order to improve their effectiveness. She aims to ensure that all the research in her group is addressing issues identified by practitioners, and is carried out collaboratively with end-users, and builds the capacity of young conservationists, particularly in developing countries. She is the founder and chair of the Saiga Conservation Alliance and has launched a number of initiatives which aim to change the real-world conversation around conservation, including the Conservation Hierarchy approach to meeting a global vision of restoring nature and the Conservation Optimism movement. She is the Chair of the UK Government's Darwin Expert Committee and a Trustee of WWF-UK
Finally, I am passionate about the conservation ecology of the saiga antelope in Central Asia, and co-founded the Saiga Conservation Alliance in 2006.
Author
While my strengths lie in statistics and data analytics, I have learnt to actively seek the wisdom of conservation practitioners and policy makers to help identify the right questions and translate results into meaningful action. I love mentoring postgraduates and collaborating with like-minded researchers to achieve shared goals.