Scientists infect rhino horns with radiation to fight poachers

Last year, about 20 rhinos at the University of the Witwatersrand Game Reserve were injected with the radioactive isotopes. Even at low concentrations, the radioactive isotopes are detectable by radiation detectors at airports and borders, allowing poachers and traffickers to be arrested.

Researchers at the Witwatersrand Department of Radiation and Medical Physics say tests conducted in a pilot study have confirmed that the radioactive material is not harmful to rhinos.

The International Union for Conservation of Nature estimates that the world's rhino population was around 500,000 at the start of the 20th century, but that number has now dropped to around 27,000 due to the continued demand for rhino horn on the black market.

South Africa has the world's largest rhino population, with an estimated 16,000, but poaching is high, with around 500 rhinos killed for their horns each year. The university has urged private wildlife park owners and national conservation authorities to inject their rhinos.