Addo facing buffalo genetics poser
Buffalo have been weighing heavily on the minds of the management team at the Addo Elephant National Park.
Park manager Nick de Goede said on Thursday the buffalo population had declined drastically since 2015 and a 2019 census showed just 420 animals in the 164,000ha protected area.
“Studies showed that in the first few years after we reintroduced lions in 2003 they had some impact on the buffaloes which were naive to large predators.
“By altering their activity patterns and habitat and increasing herd size they ensured they built up some resistance to the lions.”
However, now there was a much more serious threat, against which they had no defence, he said.
“The main cause of the population decline in recent times is due to the prolonged severe drought experienced in Addo over the past four to five years.
“To offset this situation, management have reduced predators which target buffalo — spotted hyena and lion — as well as the numbers removed annually for relocation and auction.”
Meanwhile, De Goede and his team are applying their minds to the recommendations made in a new research report on inbreeding issues in Southern African buffalo.
The report by a trio of University of Pretoria academics found that different populations of this single subspecies of African buffalo, located in different private and state-protected areas across the region, were very different genetically.
“Incredibly, Southern African Cape buffalo are more differentiated from each other than Kruger National Park buffalo are from forest buffalo, a different subspecies found in Central and West Africa.
“This high degree of differentiation is indicative of the highly fragmented nature of SA’s protected areas.
“It is another example of the human-induced population fragmentation and consequent reproductive isolation experienced by more than 25% of species globally.”
A related finding was that the Cape buffalo in the Addo elephant park, long regarded as a key reservoir of disease-free animals, was characterised by low genetic diversity, which could in time cause inbreeding and weakened offspring.
“Action should therefore be taken to re-establish gene flow either through the establishment of natural corridors between populations or through translocations from other disease-free populations to Addo,” the report said.
De Goede said he and his team welcomed the report and recognised the fragmentation issue as a concern.
SANParks’s broad approach in this regard was to try to mimic natural systems.
Because parks had to be fenced, restricting the natural movement of resident animals, different animals were periodically removed and introduced to mimic migration to and from an area.
Of concern was the recommendation that buffalo from upcountry populations should be used rather than ones in closer vicinity, which would have been more natural, he said.
“Introducing buffalo from these sources with various genetic origins could create wonderfully diverse genetics in a population, but over time it could remove the geographic genetic structuring that may be an important part of its identity.”
The suggestion that animals could be sourced from Mokala National Park in the Northern Cape would also have to be carefully assessed because although they were bred to be disease-free they were originally sourced from Kruger, where most buffalo had bovine tuberculosis, he said.
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