By Katharina Moser, Windhoek
While Namibia and other southern African countries are struggling to protect their rhinos from poaching, scientists are looking for solutions to make the rhino financially unattractive to poachers. According to a new research report published in Science magazine on June 5, dehorning is currently the most effective solution to prevent poaching.
The team of scientists led by Kuiper, Haussmann and Whitfield found that dehorning rhinos leads to a drastic reduction in poaching compared to other measures. The researchers point out that no other anti-poaching measure - such as protective fences or a higher concentration of rangers - has such a measurable effect.
In eleven reserves in southern Africa, which protect the largest rhino population in the world, the researchers documented the poaching of 1985 rhinos between 2017 and 2023, around 6.5% of the population annually, despite around 74 million US dollars being spent on anti-poaching efforts. Most of the investment focused on reactive law enforcement - rangers, sniffer dogs, access controls and detection cameras - which resulted in more than 700 poachers being apprehended, the researchers said. “However, we found no statistical evidence that these interventions reduced poaching (demand for horn, wealth inequality, criminal syndicates and corruption likely even drive high-risk poaching),” the scientists said.
“In contrast, reducing rewards to poachers through dehorning (2284 rhinos in eight reserves) resulted in a large (~78%) and abrupt reduction in poaching for an investment of 1.2% of the budget.” According to the research report, dehorning reduced poaching by more than three quarters with just over one percent of the budget. “Some poaching of dehorned rhino continued as poachers targeted horn stumps and regrowth, highlighting the need for regular dehorning along with judicious use of law enforcement.”
The numbers
According to the research report, the horns of 2284 rhinos were proactively removed in the eleven Greater Kruger reserves between 2017 and 2023, 671 cameras of seven different types were installed to detect poachers, 5562 lie detector tests were conducted (with 129 employees dismissed after failing a test) 45 sniffer dogs were deployed at the access points to the reserves, 47 sniffer dogs were deployed inside the reserves, 1150 km of sniffer zones were maintained and controlled (roads or rivers were checked for traces of poachers), and more than 500 anti-poaching rangers were on duty at all times.
In their baseline intervention model, the researchers found strong statistical evidence that dehorning reduced poaching. On average, dehorning all rhinos in a reserve reduced poaching by approximately 75% compared to the pre-dehorning period, taking into account other interventions and random effects. The number of poachers was also significantly lower after dehorning, supporting the hypothesis that poachers make fewer attempts to enter reserves with dehorned rhinos because they expect a much lower reward from poaching.
“Using data from all reserves and years, we estimated the risk of a single horned rhino being poached in a given year to be 13%, compared to a poaching risk of 0.6% for a dehorned rhino, a 95% reduction in relative poaching risk.”
While Namibia and other southern African countries are struggling to protect their rhinos from poaching, scientists are looking for solutions to make the rhino financially unattractive to poachers. According to a new research report published in Science magazine on June 5, dehorning is currently the most effective solution to prevent poaching.
The team of scientists led by Kuiper, Haussmann and Whitfield found that dehorning rhinos leads to a drastic reduction in poaching compared to other measures. The researchers point out that no other anti-poaching measure - such as protective fences or a higher concentration of rangers - has such a measurable effect.
In eleven reserves in southern Africa, which protect the largest rhino population in the world, the researchers documented the poaching of 1985 rhinos between 2017 and 2023, around 6.5% of the population annually, despite around 74 million US dollars being spent on anti-poaching efforts. Most of the investment focused on reactive law enforcement - rangers, sniffer dogs, access controls and detection cameras - which resulted in more than 700 poachers being apprehended, the researchers said. “However, we found no statistical evidence that these interventions reduced poaching (demand for horn, wealth inequality, criminal syndicates and corruption likely even drive high-risk poaching),” the scientists said.
“In contrast, reducing rewards to poachers through dehorning (2284 rhinos in eight reserves) resulted in a large (~78%) and abrupt reduction in poaching for an investment of 1.2% of the budget.” According to the research report, dehorning reduced poaching by more than three quarters with just over one percent of the budget. “Some poaching of dehorned rhino continued as poachers targeted horn stumps and regrowth, highlighting the need for regular dehorning along with judicious use of law enforcement.”
The numbers
According to the research report, the horns of 2284 rhinos were proactively removed in the eleven Greater Kruger reserves between 2017 and 2023, 671 cameras of seven different types were installed to detect poachers, 5562 lie detector tests were conducted (with 129 employees dismissed after failing a test) 45 sniffer dogs were deployed at the access points to the reserves, 47 sniffer dogs were deployed inside the reserves, 1150 km of sniffer zones were maintained and controlled (roads or rivers were checked for traces of poachers), and more than 500 anti-poaching rangers were on duty at all times.
In their baseline intervention model, the researchers found strong statistical evidence that dehorning reduced poaching. On average, dehorning all rhinos in a reserve reduced poaching by approximately 75% compared to the pre-dehorning period, taking into account other interventions and random effects. The number of poachers was also significantly lower after dehorning, supporting the hypothesis that poachers make fewer attempts to enter reserves with dehorned rhinos because they expect a much lower reward from poaching.
“Using data from all reserves and years, we estimated the risk of a single horned rhino being poached in a given year to be 13%, compared to a poaching risk of 0.6% for a dehorned rhino, a 95% reduction in relative poaching risk.”
