CAPE TOWN, Nov. 6 (Xinhua) -- Two more rhinos translocated from South Africa to Chad have died, bringing the total mortalities to four since the translocation began in May, authorities said on Tuesday.
An additional two black rhino carcasses have been discovered in Zakouma National Park in Chad following the death of two rhinos whose carcasses were discovered last month, the South African Department of Environmental Affairs said.
"We can confirm that none of these rhinos were poached," spokesperson Albi Modise said.
Post-mortems have been conducted on the rhino carcasses and various samples of blood, tissue and faecal matter were sent to specialist pathology laboratories in South Africa, according to Modise.
Histopathological results thus far have not indicated infectious diseases and plant toxicity as cause of death, said Modise.
Serological evidence has however indicated exposure to trypanosomes, a blood borne parasite transmitted by tsetse flies, but at this stage it is not suspected to be the cause of the mortalities, she said.
Low fat reserves suggest that maladaptation by the rhinos to their new environment is the likely underlying cause, although tests to be undertaken on brain and spinal fluid may shed additional light on the exact cause of deaths, Modise said.
South Africa translocated six rhinos to Chad in May this year in a bid to salvage the endangered animal from extinction.
On the advice of a team of veterinarians who are experienced in working with black rhinos, the remaining two animals are being recaptured and placed in holding facilities in order to facilitate closer management, Modise said.
South Africa, she said, has dispatched a veterinarian to Zakouma National Park to assist with the process.
Engagements between the South African and Chadian governments as well as between the South African National Parks and non-governmental African Parks in Johannesburg remain active as efforts continue to be made to establish clarity around the exact cause of deaths of the four rhinos, and to safeguard the remaining two animals, Modise added.
South Africa and Chad signed an agreement in 2017 for the translocation of rhinos which have faced high levels of poaching for the past decade.
South Africa has also translocated black and white rhinos to a number of other African countries, including Botswana, Tanzania, Zambia, Malawi, Rwanda, Namibia, Mozambique, Kenya and Swaziland.
South Africa, home of more than 80 percent of rhino population in the world, bears the brunt of rhino poaching, losing 1,028 rhinos to poaching last year.