Dehorning rhinos tips the balance against poaching – new study

Timothy Kuiper, Nelson Mandela University

Black and white rhino populations in the Greater Kruger (Kruger National Park and surrounding reserves) in South Africa have plummeted from over 10,000 rhinos in 2010 to around 2,600 in 2023. Hundreds of rhinos are killed each year by poachers for their horns. These are sold on the illegal global market.

Nature reserve managers, rangers, international funders, and local non-profit organisations have invested millions of dollars in anti-poaching interventions. These include tracking dogs to track poachers, artificial intelligence-enabled detection cameras, helicopters to monitor reserves and, more recently, dehorning (removing rhinos’ horns reduces the incentive for poachers).

To see if these were working, the Greater Kruger Environmental Protection Foundation set up a research project involving several reserve managers, rangers, and scientists from the University of Cape Town, Nelson Mandela University, University of Stellenbosch, and the University of Oxford.

The South African National Parks, World Wildlife Fund South Africa, and the Rhino Recovery Fund were also involved.

Together, managers and scientists gathered seven years of rhino poaching data across 2.4 million hectares in the north-eastern region of South Africa and western Mozambique. During this time, we documented the poaching of 1,985 rhinos across 11 reserves in the Greater Kruger area. This number is about 6.5% of the rhino populations in these reserves annually.

This landscape is a critical global stronghold that conserves around 25% of all Africa’s rhinos.

Our study’s headline result was that dehorning rhinos to reduce incentives for poaching achieved a 78% reduction in poaching (average reduction across implementing reserves). This was based on comparison between sites with and without dehorning as well as changes in poaching before and after dehorning. Exactly 2,284 rhinos were dehorned across eight reserves over the seven years of our research – this was most of the rhino in the region.

Our findings show that significant progress can be made against rhino poaching by reducing the reward attached to poaching (removing the horn). This is a strategic shift in focus away from purely focusing on increasing risks to poachers.

But we are being careful to note that dehorning is not a complete solution. Our research found that 111 rhinos were poached even though they had been dehorned. This is because up to 15cm of horn is left on the rhino when it is dehorned by veterinarians. This is to protect the growth plate at the base of the horn.

Rhinos’ horns regrow over time. During our fieldwork, we also noticed that criminal syndicates remain willing to kill rhinos for their stumps, even if they do this at lower rates than before dehorning.

It may be best to think of dehorning as a very effective but short-term solution that buys us time to address the more ultimate drivers of poaching: horn demand, socio-economic inequality, corruption, and organised criminal networks.

A different approach to pinning down the problem

Part of what made our study special was its strong focus on collaboration between managers and scientists. The project was first conceived by reserve managers at the frontline of rhino conservation and led by Sharon Haussmann, chief executive officer of the Greater Kruger Environmental Protection Foundation. They recognised the need to take a look at whether their investments into tracking dogs, artificial intelligence cameras and other anti-poaching interventions were paying off.

Faced with a poaching crisis despite millions of dollars invested in law enforcement, security and technology, Sharon and the team were bold enough to ask: “Why are we still losing so many rhinos? What could we do differently?” These managers then began working closely with scientists to tackle this problem together through our research.

Tragically, Sharon died unexpectedly on 31 May, less than a week before our research was published. We want to dedicate this research to her legacy.

Detecting and arresting poachers alone is not enough

The nature reserves we studied had invested US$74 million (R1 billion) in anti-poaching interventions between 2017 and 2021. Most of the investment focused on reactive law enforcement – rangers, tracking dogs, helicopters, access controls and detection cameras. This helped achieve over 700 poacher arrests. Yet we found no statistical evidence that these interventions significantly reduced poaching.

Why? These interventions are a necessary element of the anti-poaching toolkit. But they were compromised by bigger challenges. For example, stark socio-economic inequality in the region creates the ideal conditions for crime to thrive, and criminal syndicates find it easy to recruit people willing to take the large risk of poaching rhino.

Entrenched corruption among police and reserve staff allowed offenders access to inside information on the locations of dogs, cameras and rhinos. This meant that poaching was not deterred as much as it could have been.

Finally, ineffective criminal justice systems mean that arrested offenders often escape punishment, with evidence from the Greater Kruger of poachers who were multiple repeat offenders.

What can be done differently?

A range of interventions will be needed to complement dehorning, particularly as poaching for stumps would probably continue if there were no risk to poachers. There is also some evidence that dehorning rhino in one area means poachers may move to another area where rhino still have horns and poach there instead. (This has happened in South Africa’s second largest rhino stronghold in Hluhluwe-iMfolozi Park where rhino have not been dehorned.)

Our findings challenge the conventional wisdom that detecting and arresting poachers is enough on its own. Instead, we recommend these measures:

1. Give local people a voice and a stake. Many people affected by rhino conservation have no say and don’t share in the benefits of the industry.

2. Disrupt transnational criminal networks outside protected areas through intelligence-led investigations (follow the money).

3. Continue supporting dehorning in the short term. This will buy time to solve the biggest drivers of wildlife crime: inequality, horn demand, and corruption.

4. Dehorning needs to be supported by other measures to protect the rhino.

5. Support people first, then interventions. Rangers are key here – their welfare, wages, training and safety are not always given the attention or funding they deserve.

6. Keep loving rhinos and buying your kids pyjamas with them on.

Timothy Kuiper, Senior Lecturer - Biodiversity and Statistics, Nelson Mandela University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More........→June 07, 2025

This Common Fungus Found on Human Skin Wipes Out Deadly Superbug Staph Infections

University of Oregon researchers have uncovered a molecule produced by yeast living on human skin that showed potent antimicrobial properties against a pathogen responsible for a half-million hospitalizations annually in the US.

It’s a unique approach to tackling the growing problem of antibiotic-resistant bacteria. With the global threat of drug-resistant infections, fungi inhabiting human skin are an untapped resource for identifying new antibiotics, said Caitlin Kowalski, a postdoctoral researcher at the UO who led the study.

Described in a paper published last month in Current Biology, the common skin fungus Malassezia gobbles up oil and fats on human skin to produce fatty acids that selectively eliminate Staphylococcus aureus.

One out of every three people have Staphylococcus aureus harmlessly dwelling in their nose, but the bacteria are a risk factor for serious infections when given the opportunity: open wounds, abrasions and cuts. They’re the primary cause of skin and soft tissue infections known as staph infections.

Staphylococcus aureus is also a hospital superbug notorious for being resistant to current antibiotics, elevating the pressing need for new medicines.

There are lots of studies that identify new antibiotic structures, Kowalski said, “but what was fun and interesting about ours is that we identified (a compound) that is well-known and that people have studied before.”

The compound is not toxic in normal lab conditions, but it can be potent in conditions that replicate the acidic environment of healthy skin. “I think that’s why in some cases we may have missed these kinds of antimicrobial mechanisms,” Kowalski added, “because the pH in the lab wasn’t low enough. But human skin is really acidic.”

Humans play host to a colossal array of microorganisms, known as the microbiome, but we know little about our resident fungi and their contributions to human health, Kowalski said. The skin microbiome is of special interest to her because while other body parts crowd dozens of different fungi, the skin is dominantly colonized by one kind known as Malassezia.

Malassezia can be associated with cases of dandruff and eczema, but it’s considered relatively harmless and a normal part of skin flora. The yeast has evolved to live on mammalian skin, so much so that it can’t make fatty acids without the lipids—oils and fats—secreted by skin.

Despite the abundance of Malassezia found on us, they remain understudied, Kowalski said.

“The skin is a parallel system to what’s happening in the gut, which is really well-studied,” she said in a media release. “We know that the intestinal microbiome can modify host compounds and make their own unique compounds that have new functions. Skin is lipid-rich, and the skin microbiome processes these lipids to also produce bioactive compounds. So what does this mean for skin health and diseases?”

Looking at human skin samples from healthy donors and experiments done with skin cells in the lab, Kowalski found that the fungal species Malassezia sympodialis transformed host lipids into antibacterial hydroxy fatty acids. Fatty acids have various functions in cells but are notably the building blocks for cell membranes.

The hydroxy fatty acids synthesized by Malassezia sympodialis were detergent-like, destroying the membranes of Staphylococcus aureus and causing its internal contents to leak away. The attack prevented the colonization of Staphylococcus aureus on the skin and ultimately killed the bacteria in as little as 15 minutes, Kowalski said.

But the fungus isn’t a magic bullet. After enough exposure, the staph bacteria eventually became tolerant to the fungus, as they do when clinical antibiotics are overused.

Looking at their genetics, the researchers found that the bacteria evolved a mutation in the Rel gene, which activates the bacterial stress response. Similar mutations have been previously identified in patients with Staphylococcus aureus infections.

The findings show that a bacteria’s host environment and interactions with other microbes can influence its susceptibility to antibiotics.

“There’s growing interest in applying microbes as a therapeutic, such as adding bacteria to prevent the growth of a pathogen,” Kowalski said. “But it can have consequences that we have not yet fully understood. Even though we know antibiotics lead to the evolution of resistance, it hasn’t been considered when we think about the application of microbes as a therapeutic.”

While the discovery adds a layer of complexity for drug discovery, Kowalski said she is excited about the potential of resident fungi as a new source for future antibiotics.

Identifying the antimicrobial fatty acids took three years and a cross-disciplinary effort. Kowalski collaborated with chemical microbiologists at McMaster University to track down the compound.

“It was like finding a needle in a haystack but with molecules you can’t see,” said Kowalski’s adviser, Matthew Barber, an associate professor of biology in the College of Arts and Sciences at the UO.

Kowalski is working on a follow-up study that goes deeper into the genetic mechanisms that led to the antibiotic tolerance. She is also preparing to launch her own lab to further investigate the overlooked role of the skin microbiome, parting from Barber’s lab after bringing fungi into focus.

“Antibiotic-resistant bacterial infections are a major human health threat and one that, in some ways, is getting worse,” Barber said. “We still have a lot of work to do in understanding the microorganisms but also finding new ways that we can possibly treat or prevent those infections.”[Source: By Leila Okahata, University of Oregon] This Common Fungus Found on Human Skin Wipes Out Deadly Superbug Staph Infections

Read More........→June 06, 2025