The study found that within a protected area, no Vulture nests were found in a fenced section where Elephants were introduced some years ago, but were fairly common outside of the area, coming right up to the perimeter fence.
This is attributed to the Elephants knocking down big trees that form potential nesting sites for the large birds. The study was carried out by Ara Monadjem from the University of Swaziland in the Hlane-Mlawula protected area in northeastern Swaziland.
Commenting on the study, head of the Endangered Wildlife Trust's Birds of Prey Working Group, Andre Botha, said, "Elephants in safe havens are as much of a threat [to Vultures] as poison, persecution and power lines if they are not managed."
A comparison of Vulture nest density found that Swaziland and protected areas near Kimberley in South Africa had comparable numbers of nests in a given area. However, while these two areas had about 100 nests/100km2, the Kruger National Park, Klaserie Private Nature Reserve and protected areas in Zimbabwe had around 10 nests/100km2. Hluhluwe had around 20 nests/100km2.
Monadjem's study found that in Swaziland all raptors, and particularly Vultures, were up to five times more commonly found in protected national parks than in privately protected land or in farming areas. Botha says that Elephants are not endangered, but all large raptors are listed as threatened with extinction in the Red Data bird list for southern Africa.
He says that many of South Africa's birds of prey depend on Kruger as a safe place to breed, and if the trees they nest in are lost, "It is like taking the dam away from under the duck." He is hoping that in the near future a study that monitors raptor nests in the Kruger National Park will be undertaken.