In 2015 alone, 1,349 rhinos were poached in Africa. In the years since, those numbers have decreased, but at least one rhinoceros is still killed every day. To tackle this problem, a group of researchers has come up with an out-of-the-box ideaâwe mean really out of the box.Â
Make their horns radioactive.Â
Rhino poaching is primarily motivated by the demand for their horns in countries such as China and Vietnam. The idea behind the Rhisotope Project is that buyers wonât be interested in horns injected with radioisotopes (radioactive versions of an element), and even if they are, border controls could use radiation-detection technology to detect the illegal goods.Â
âIt was one of those three oâclock in the morning thoughts: âWhat if I put a small amount into the horn?ââ explained James Larkin, a professor at University of Witwatersrand in South Africa, rhino poaching hotspot. âI realized we could probably find that sweet spot where the dose was small enough to not harm the animal, but big enough to set off a detector.â
In that spirit, Larkin and colleagues injected low levels of radioactive isotopes in the horns of 20 rhinos at Waterberg Biosphere Reserve during a trial phase six months ago. Consequent blood tests and veterinary inspections confirmed that the rhinos were unharmed. Specifically, the researchers analyzed the rhinoâs blood for micronuclei in their white blood cellsâa known sign of cellular damage. They did not find any micronuclei during the tests.

But for the theory to work, the doses need to be traceable by radiation detection technology. As such, the team âsimulated transport scenarios with the 3D-printed horns on carry-on luggage, air cargo shipments and priority parcel delivery systems,â Larkin explained in a recent statement. The printed horns had similar properties to keratin, the same material that real rhino horns are made of. Clearly, no one thought sticking a real rhino through a TSA scanner was a good idea. Â
âIn each case, even a single horn with significantly lower levels of radioactivity than what will be used in practice successfully triggered alarms in radiation detectors,â he added. The detectors even caught individual horns inside full 40-foot shipping containers.Â
[ Related: Rhino horns are shrinking, and humans are to blame. ]
With the approach proven to be both safe and effective, the Rhisotope Project becomes officially operational this month, meaning that owners can request for their rhinos to be treated with radioisotopes.Â
âOur goal is to deploy the Rhisotope technology at scale to help protect one of Africaâs most iconic and threatened species,â said Jessica Babich, Rhisotope Project CEO. âBy doing so, we safeguard not just rhinos but a vital part of our natural heritage.âÂ