The Department of Environmental Affairs reported Thursday that 42 rhinos alone had been poached in Kruger National Park, a vast wilderness that straddles the Mozambique border. The park accounts for 40 percent of the world rhino population.
The park authorities blamed the staggering rate of kills on "recent floods in the Kruger National Park, thick vegetation, two weeks of a full moon, aggressive incursions from Mozambique".
The department said 18 suspected poachers have been arrested this year.
South Africa's estimated 20,700 rhinos, the largest in the world, had a population growth rate of six percent a year before rhino poaching escalated by 35% between 2010 and 2011, according to statistics from SANParks.
A record 668 rhinos were killed in South Africa in 2012, an increase of nearly 50 percent over the previous year.
Demand is growing in Vietnam and elsewhere in Asia where rhino horn is believed to have medical benefits despite evidence to the contrary. The horn is made of keratin, a protein also found in human fingernails.
Elephant poaching for the beasts' ivory tusks is also rising across Africa.
South African authorities have stepped up anti-poaching operations in the Kruger Park, including deploying the army to the park along with a surveillance aircraft.