Finally tonight, the black market trade in rhino horns is driving these species to near extinction.

Now scientists at a rhino orphanage in the bushveld of South Africa are trying to protect them from poaching in a rather surprising way.

The first step is to carefully sedate beasts that can weigh up to two and a half tons.

Then the scientists get to work with a drill.

They insert radioactive isotopes into the rhino's horns and amounts too small to affect their health.

It's called the rhizotope project. James Larkin of the University of Witts Watersrand

set it up in 2021. By making the horns radioactive, we are making those horns, devaliering those

horns in the eyes of the poacher and the end users. No one wants a radioactive horn.

South Africa has the world's largest population of rhinos, and hundreds of them are poached

every year. It's a major threat to the critically endangered rhinos, driven by the lucrative

black market for their horns, which are popular in some Asian countries in traditional medicine

and as status symbols.

The goal of the rhizotope project is to make horns virtually impossible to traffic.

All these rhinos are here because they were often because their mothers were shot.

They're a poach because of the value of the rhino horn.

Now with the rhizotope project, you can't take that horn anywhere.

It is radioactive.

You can't take it through any airport, any harbor, any customs office.

Sirens go off.

It is wonderful.

I'm telling you this could be the Holy Grail to save the species.

The effort is supported by the International Atomic Energy Agency.

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