DINOKENG GAME RESERVE, South Africa (AP) — The Dinokeng Game Reserve in South Africa has a thriving rhino population, but their exact numbers and the details of the security operation that keeps them safe from poaching are closely guarded secrets.

They are the protocols that reserves with rhinos follow to ensure they're not the next target for poachers who still kill on average one rhino every day in South Africa for their horns despite decades of work to save the endangered species.

South Africa has the largest populations of both black and southern white rhinos of any country and sees itself as the custodian of the animals' future.

As conservationists mark World Rhino Day on Monday, South Africa remains in a constant and costly battle against poaching nearly 30 years after black rhino

See Full Page