Forty-nine dead vultures found on a farm in the Swartberg area of KwaZulu-Natal were poisoned, the Endangered Wildlife Trust (EWT) said on Friday.
Spokesperson Cobus Theron said the carcasses were spotted by an Ezemvelo KwaZulu-Natal plane on the farm in the Swartberg area north of Kokstad on 15 July.
The vultures, as well as some sheep, are believed to have been poisoned by a farmer in a bid to stop jackals hunting recently born lambs.
Theron said tests on the carcasses of the 48 Cape vultures and an African white-backed vulture showed they had died after ingesting Carbofuran, a pesticide commonly used to destroy worms in crops.
Two Cape vultures were found alive and had responded to treatment.
“This is the worst case of vulture poisoning I have seen in the 12 years I have been working with birds of prey in the province,” said Ben Hoffman of Raptor Rescue, a bird of prey hospital located at the African Bird of Prey Sanctuary.
The Cape vulture is listed as vulnerable with about 8 000 birds in the wild, while the white-backed vulture is listed as endangered.