Welgevonden Private Game Reserve is the latest reserve to begin an elephant immunocontraception programme similar to those currently being carried out on Makalali Game Reserve, Phinda Nature Reserve and Thornybush Nature Reserve.
Welgevonden has a total of 100 elephants in 34,200ha. It adjoins Marakele National Park, identified by environment minister Marthinus van Schalkwyk as one of the national parks where "there are biodiversity concerns with regard to the management of elephants".
Elephants were reintroduced to Welgevonden from Kruger National Park (KNP) about a decade ago, making their mark on the sourveld vegetation there for the first time in a century.
Chief executive Andrew Parker said, "We feel that the elephant population is already at its upper limit" and the decision to introduce contraception was discussed at the reserve's last annual general meeting.
The reserve also plans to decrease its elephant population by relocating about 10 animals to the Eastern Cape. The 43 elephants to undergo contraception have been injected from a helicopter with a dart containing PZP (porcine zona pellucida). PZP contains pig proteins that cause the elephant's immune system to create antibodies.
The antibodies stop sperm from fertilising eggs, and so make the elephant temporarily sterile without affecting its reproductive hormones. Three shots are needed per elephant, administered about a month apart, to ensure effective contraception when the programme is started.
After that, a booster shot once a year keeps antibody levels high enough to prevent the elephants from becoming pregnant. Welgevonden will appoint a full time elephant monitoring assistant to ensure the contraception programme has no adverse effects. They are currently looking for a suitable candidate for the position.