Workers attempt to bring a tranquillised black rhino to the ground before dehorning in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)





A tranquillised black rhino falls to the ground as workers attempt to help it before dehorning it in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa,February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)





A tranquillised black rhino is dehorned in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)





A veterinarian inspects a tranquillised black rhino after it was dehorned in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa,February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)





Black rhinos, one of the world's endangered animals, are seen at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)





A tranquillised black rhino is dehorned in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)





A worker holds rhino horns after it was dehorned in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa,February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)





A black rhino is seen after it was dehorned in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)