Four of the six critically endangered black rhinos translocated to Chad from South Africa in a landmark range expansion exercise in May have now died.
The South African and Chadian governments said in October that two animals had died – but two reliable sources have confirmed the death of two more members of the group.
“The rhinos were being photographed once a week and the latest images showed they were in near prime condition,” one source said on Tuesday.
“There was no gradual loss of health. But two more animals have now died, bringing the total to four.”
Algal blooms in the waterholes – which killed a number of animals in the Kruger National Park in 2005 – were initially thought to be a possible cause of death.
Algal blooms were caused by faeces and urine from resident hippos, combined with declining water levels, in line with the present conditions in Zakouma, which was entering the dry season.
But this possibility had been checked and discarded by a range of experts and initial tests, the source said.
“They weren’t shot by poachers or poisoned via a waterhole, and it’s not algal blooms. It’s not clear what it is.
“But something has sneaked in. Tsetse fly or some kind of arbovirus is a possibility.”
Of the two remaining animals, one had already been captured and was in a boma in good condition, while rangers were trying to capture the last one on Tuesday.
A SANParks veterinarian was on site in Zakouma this week and he would soon be dispatching a final set of samples from the dead animals, their dung, the water and the plants on which they were feeding to Pretoria to be analysed at Onderstepoort laboratory, the source said.
An initial batch was already being studied and more were en route.
The six rhinos were originally from the Marakele National Park in Limpopo’s Waterberg Mountains and spent three months in bomas at the Addo Elephant National Park before being flown to the Zakouma National Park on May 3.
The move was undertaken in terms of a partnership between SANParks, the SA department of environmental affairs, the Chad government and African Parks, a private nonprofit organisation managing Zakouma and 14 other African protected areas.
The Addo farewell event was attended by late environment minister Edna Molewa, who said the aim was to launch the rebirth of Chad’s black rhino population after it was poached to extinction 46 years ago.
The species range would be extended, and Chad’s conservation and tourism industry would benefit, she said.
After taking over management of Zakouma in 2010, African Parks’s initial challenge was to halt poaching by Janjaweed militia from Sudan.
This was done by establishing a “peace dividend” for surrounding communities who were also being terrorised by the Janjaweed.
A second source said on Tuesday that the rhinos had been closely monitored. “The rangers had sight of the animals on average every second day.
“They did not want to push onto them more than that because it might have caused them anxiety.”
Zakouma had been carefully checked by a rhino specialist and an ecologist before the relocation project went ahead, he said.
“The habitat was right and there were no records of animal deaths that showed anything to be concerned about.
“It’s too early to say what will happen now with the project.”
Questions were sent to the department of environmental affairs, which did not respond.
SANParks contractor and unofficial rhino-whisperer Wilson Nxleko, who played a key role looking after the animals in the bomas at Addo, said he was saddened by news of the four deaths.
“It is a great shame. They were part of us,” he said.