This is how humans reduced 1,000 Knysna elephants to just one
A new study, the first of its kind, looks into the decline of the forest elephants, and comes up with three hypotheses
An estimated 1,000 elephants roamed the Outeniqua-Tsitsikamma area before the arrival of Jan van Riebeeck 367 years ago. Today, just one remains.
Now a new study, the first of its kind, looks into the decline of the Knysna forest elephants and how humans can change their behaviour to prevent similar extinctions.
The study, headed by South African National Parks and supported by Nelson Mandela University, was published on Wednesday in the latest South African Journal of Science.
African elephants (Loxodonta africana) are declining across the continent, “largely because they are poached for their ivory”, said researchers led by Lizette Moolman, of SANParks scientific services.
In SA, however, elephant populations had increased in recent years, leaving the Knysna population as an “anomaly”, all but wiped out despite a protection order dating from the early 1900s.
“They are the most southern group of elephants in Africa, the only remaining free-ranging elephants in South Africa, and represent one of four relict populations in the country,” said the researchers.
Before the arrival of Europeans, it was estimated that “3,000 elephants roamed the Cape floristic region”, including around 1,000 in the Knysna area.
Then, between 1856 and 1886, “Knysna experienced a marked influx of people and a boom in development which increased human-elephant conflict” at a cost to the elephants.
By the late 1800s there were about 400 to 500 elephants in the area, but by the end of that century there were only “30 to 50 individuals left”.
It was around this time that an attitude shift came from seeing the elephants as “a nuisance” to seeing them as a “local asset”, and in 1908 the authorities declared them “royal game”, protecting them from hunters.
The researchers wanted to know why this effort to save the elephants failed, because “management of this population is challenging if the cause of the decline is not clear”, and they came up with three hypotheses which they said probably combined to doom the Knysna elephants.
The “refugee hypothesis” says the elephants were forced to change habitats because of humans, and this severely affected their health and fitness.
They had originally lived in open areas, but human settlement and agricultural activity forced them to take refuge in the forest where the quality of food was much poorer.
“Human disturbance and encroachment displaced the local elephants from other more optimal habitats into poor-quality habitats of the forest and its surrounding fynbos,” said the researchers. “The decline then resulted from a limitation of good-quality food.”
As early as 1755, travellers in the southern Cape “noted the ongoing shooting of the elephants”, and the record implies that these elephants “chose the forests as they provided safety from human disturbances”, rather than for any “nutritional and other life-history needs”.
Newborns began dying at a much more rapid rate, and the researchers said female elephants “under nutritional stress have been shown to have calves which have lower survivorship”.
The calf mortality rate for Knysna elephants in the 1900s was said to be 60% to 80%, compared with 7.5% in the Addo Elephant National Park, where the elephants roam freely in a suitable habitat.
The “illegal killing hypothesis” suggests the elephants were able to adapt to the forest and its immediate fynbos habitat, but their decline was a direct result of hunting which continued in defiance of the protection order.
The elephants roamed mostly on forestry land, but “forestry officials had no authority to protect the elephants when they moved off forestry land, even after they were declared royal game”, said the researchers.
Additionally, it was speculated that the forestry department had a “negative attitude towards the elephants” and that even the “total destruction of the elephants was advocated in some quarters during the 1920s”.
One standout incident was in 1920, when Major PJ Pretorius was given a permit to shoot one elephant for “scientific purposes”. By the end of his hunt, he had killed five, leaving just 13 alive.
The “stochastic founder population hypothesis” says the population size and structure left it “vulnerable to demographic stochasticity”.
This means the extinction risk in such a small population that kept growing smaller was high because of “independent events of individual mortality and reproduction”.
During the 1900s, the Knysna elephant population had split into small groups, mostly consisting of “an adult cow and her calf”. This meant the severe lack of allomothering [infants being cared for by adults other than their own parents] “may have played a significant role in reduced calf survival”.
The researchers concluded that all these drivers played a part in the near extinction of the Knysna elephants: the population was decimated in the 1700s and 1800s; the survivors took refuge in the forest, which was far from suitable; illegal killings continued after protection; and the elephants then suffered from the stochastic effects of being such a small population.