South Africa's efforts to stem the poaching of endangered rhinos for their horns failed to prevent another 5 percent of the population being slaughtered last year.

South Africa has more than 80 percent of the world's estimated population of just 25,000 rhinoceroses. A total of 1,028 were poached in 2017, just 26 fewer than the previous year, the Environmental Ministry said in a statement.

Despite efforts to prevent poaching through patrols, electronic surveillance and monitoring of ports and borders, as well as raising awareness, arrests of suspected rhino poachers and traffickers fell by almost a quarter to 518 last year.