South African scientists on Tuesday injected radioactive material into live rhino horns to make them easier to detect at border posts in a pioneering project aimed at curbing poaching.

The country is home to a large majority of the world’s rhinos and as such is a hot spot for poaching driven by demand from Asia, where horns are used in traditional medicine for their supposed therapeutic effect.

At the Limpopo rhino orphanage in the Waterberg area, in the country’s northeast, a few of the thick-skinned herbivores grazed in the low savannah.

James Larkin, director of the University of the Witwatersrand’s radiation and health physics unit who spearheaded the initiative, told AFP he had put “two tiny little radioactive chips in the horn” as he administered the radioisotopes on one of the large animals’ horns.

The radioactive material would “render the horn useless… essentially poisonous for human consumption,” added Nithaya Chetty, professor and dean of science at the same university.

The dusty rhino, put to sleep and crouched on the ground, did not feel any pain, Larkin said, adding that the radioactive material’s dose was so low it would not impact the animal’s health or the environment in any way.

In February the environment ministry said that, despite government efforts to tackle the illicit trade, 499 of the giant mammals were killed in 2023, mostly in state-run parks. That represents an 11% increase over the 2022 figures.

Twenty live rhinos in total are to be part of the pilot “Rhisotope” project, whereby they would be administered a dose “strong enough to set off detectors that are installed globally” at international border posts that were originally installed to thwart nuclear terrorism, Larkin said.

Border agents often have handheld radiation detectors that can pick up contraband, in addition to thousands of radiation detectors installed at ports and airports, the scientists said.

“Best idea I’ve ever heard”

According to Arrie Van Deventer, the orphanage’s founder, efforts including dehorning rhinos and poisoning the horns have failed to deter poachers.

“Maybe this is the thing that will stop poaching,” the conservationist said. “This is the best idea I’ve ever heard.”

Wildebeest, warthogs and giraffe roamed the vast conservation area as more than a dozen team members performed the delicate process on another rhino.

Larkin meticulously drilled a small hole into the horn and then hammered in the radioisotope.

About 15,000 rhinos live in South Africa, according to an estimate by the international Rhino foundation.

The last phase of the project will ensure the animals’ aftercare, following “proper scientific protocol and ethical protocol,” said the project’s COO, Jessica Babich. The team will take follow-up blood samples to ensure the rhinos were effectively protected.

The material should last five years in the horns, which Larkin said was a cheaper method than dehorning the animals every 18 months when their horns grow back.

Why are rhino horns poached?

High demand for rhino horns has fueled an illegal market. In parts of Asia, the horns are thought to have unproven, powerful medicinal properties and at one point they were more expensive than cocaine in Vietnam.

Even though the horns grow back, poachers kill rhinos instead of sedating them to cut off the horns. In response, several initiatives have been launched to thwart poachers, including moving rhinos to different parts of Africa to get them out of poachers’ reach and also safely removing rhinos’ horns so they’re not targeted.

During the coronavirus pandemic, rhino poaching surged across Africa as a lack of funding caused security shortages in conservation areas. 

Earlier this month, authorities in Indonesia announced six poaching suspects were arrested, accused of being part of a network that used homemade firearms to kill more than two dozen critically endangered  Javan rhinos since 2018 to get their horns.

Last year, a Malaysian man known as the “Godfather” who sold a dozen black rhino and white rhino horns to a confidential source was sentenced to a year and a half in a U.S. prison.

Alex Sundby contributed to this report.