Unsupervised elephant youth terrorized other wildlife — until adults set them straight
It was conceived as a rebirth of the Garden of Eden — until the rhinos started turning up dead.
This was in 1993, in the then-decade-old Pilanesberg National Park, in South Africa. Poachers, you might guess. But in this instance, the deceased animals still had their horns intact. Those critical clues led the park’s rangers-turned-detectives to keep looking for other suspects in the slaying of the endangered rhinos.
In what became a confounding case of whodunnit, all the usual suspects were ruled out. If anything, the forensic evidence — lacerations on the rhinos’ upper shoulders and back — seemed to indicate that the rhino killers had … tusks.
The very idea that elephants could be responsible for the rhino deaths was so preposterous that the Pilanesberg team set up an enormous stake out, with hidden cameras and radio-collared rhinos, to see if they could obtain visual proof. And, indeed, the stunned observers soon had such first-hand evidence — the ones who had committed the heinous acts were roving gangs of young male elephants.
“Observers reported that young male elephants had launched unprovoked attacks on white rhinos,” Dr. Graeme Shannon, then a behavioral ecologist from the UK’s University of Sussex — who studied the elephants of Pilanesberg with his Sussex colleague Karen McComb — told Moving Giants.
As Psychology Today magazine wrote in a piece years later, “This was virtually unheard of, anywhere. Elephants and rhinos certainly interact with one another in the wild, but it never ends in one of them killing the other — never. But here it had, and many times over many years.”
What could possibly have led these elephants to their rhino-cidal rage?
The rogue elephants of Pilanesberg were soon dubbed the Delinquents.
The history of the Delinquents dovetails with the beginnings of Pilanesberg National Park, which was established in the early 1980s. The idea for Pilanesberg — situated about halfway between the capitals of South Africa and Botswana, in the northwest of the former — was an ambitious project to create a new game reserve by reclaiming farmland and other territory. The original plan to populate the park with wildlife was called Operation Genesis, and it involved translocating 6,000 animals into the newly launched reserve.
Among the animals translocated to Pilanesberg were about 20 young elephants — all between five and eight years old — from South Africa’s massive Kruger National Park. Kruger at that time had an overpopulation of elephants. And, sadly common for that era, the conservation philosophy regarding elephants favored culling adults and translocating calves. The technology for translocating entire elephant families — as is now possible and preferred — simply didn’t exist.
So these orphaned elephant calves were moved from the overcrowded Kruger to the newly created Pilanesberg. But elephants, a matriarchal species, are raised communally by the adult females of a breeding herd, and further kept in line by roaming solo adult male bulls. And what researchers did not know then — and know very well now, mainly thanks to the Delinquent elephants in both Pilanesberg and neighboring Madikwe National Park (three hours to the northwest of Pilanesberg, hard up on the Botswana border) — is that the life lessons imparted from adult elephants to calves greatly shapes the behavior — even involuntary behavior — of the calves.
In other words, without the strict and gradual teachings of adult elephants, young male calves grew up to be uncontrollable adolescent ruffians.
In what became a confounding case of whodunnit, the forensic evidence — lacerations on the rhinos’ upper shoulders and back — seemed to indicate that the rhino killers had … tusks.
The 20 young elephants imported to Pilanesberg from Kruger were split evenly in gender, but the Delinquent elephants were all male. And these male elephants — who had spent the last 10-or-so years without any adult supervision — were all in a state of musth (a heightened sexual state common for male elephants). What was unusual, though, about their musth state was that all of these male elephants were in musth at the same time. Nature usually intervenes to stagger male musth, so that not all males are in the same state at the same time — otherwise, musthed males might kill each other. Why were these elephants different, and all in musth at the same time?
As reported by the Kota Foundation for Elephants, an organization whose “programs and services aim to educate people about elephants as a way to support positive outcomes for their survival” (and a Moving Giants “Elephant Champion”), the Delinquents’ musth-levels were baffling “because the elephants were between the ages of 13 and 18 and though a young bull elephant will begin producing sperm in their early teenage years, a bull elephant had never been spotted in full-blown musth until the normal age of 28. These young individuals had gone into this heightened state of sexual maturity nearly 10 years early.”
Psychology Today reported that “Without adult males to keep them in check through the normal behavioral interactions between teenage males and adult males, the fatherless, adult-male-less teens had matured too quickly. The hormone surge of testosterone associated with musth was, apparently, too much to handle at 15 to 18 years of age. This had spilled over into highly aggressive behavior by these teenage males. And that aggression was vented, in part, on their unfortunate white rhino victims.”
The Delinquents began to attract international attention. A Los Angeles Times article from 1998 reported that, “Rebuffed by older elephant cows, some teenage bulls have taken to mating with the white rhinoceros, the largest available pachyderm around. Several rhinos have been killed in the process. Other young bulls are taking out their aggression on people, charging groups of tourists who roam Pilanesberg's unpatrolled dirt roads in private vehicles.”
At some point, a lightbulb went off over the collective heads of the researchers at Pilanesberg.
As reported by CBS News, “With nearly 10% of the park’s total rhino population killed by teenage elephants park officials decided to try something never attempted before. Now, nearly 15 years after the culling in Kruger National Park they had discovered ways to transport full-grown elephants. They decided to bring in several large bulls and females from Kruger National Park that were in their mid to late 40’s as an experiment to see what the younger generation would do with an older one watching over them.”
The largest bull — Amarula — became something of an instant sensation among the Delinquents.
“Almost immediately the younger males approached Amarula,” reported CBS News. “Smaller elephants hero worship ones larger and older than they are. However when one is in a musth state he will go up and try to provoke even the largest elephants as was the case with a younger male. Amarula wasted no time and hit the younger elephant so hard in the stomach that he flew several feet up into the air. This served as a warning to the younger group, that they were no match for a male the size of Amarula.”
And that was the end of the Delinquents reign of terror. The elephant killings of rhinos ceased immediately.
“The crucial role of older, more dominant males in the social hierarchy,” Dr. Shannon — now Lecturer at Bangor University’s (Gwynedd, UK) School of Natural Sciences — tells Moving Giants, “was demonstrated following the translocation of six mature males to the reserve following a spate of aggressive behavior from the young resident males who were entering musth at a very young age for unusually long periods. Older bull elephants control young males. The translocation of the larger, older and more dominant bull elephants from Kruger National Park led to a reduction in musth by younger males and an end to the killing of rhinos.”
The larger scope of work by Shannon and McComb was to juxtapose two elephant groups: the orphans from Kruger that were translocated to Pilanesberg and a relatively undisturbed group living in Amboseli National Park in Kenya.
“The more recent work that Karen and I conducted,” notes Shannon, “demonstrated that despite the fact that the orphan elephants translocated in the late 1970s and early ‘80s had formed relatively stable family groups during the subsequent decades, their ability to handle crucial social knowledge had been severely compromised. Effects of social disruption in elephants persist decades after culling.”
“Our work shows clearly how vital the social fabric of elephant populations is for healthy and adaptive functioning,” adds McComb, Professor of Animal Behavior & Cognition at the University of Sussex’s School of Psychology. “It’s not just a numbers game — disrupting the intricate social fabric of their lives has detrimental effects that can persist for decades.”
“The work in Pilanesberg contributed to our understanding of the long-term traumatic effects of culling,” notes Shannon, “particularly when the young ‘survivors’ were then translocated to establish new populations in the absence of older related individuals. These young elephants appear to be much more prone to aberrant behavior (e.g., hyper aggression) and elevated stress levels that are commonly associated with PTSD in humans. Following the moratorium on culling in South Africa in 1995, translocation techniques were also greatly improved using the latest scientific evidence, so that instead of moving unrelated individuals, entire family groups were translocated, which greatly reduced the level of social trauma associated with elephant population management.”
Today, moving entire family groups is a key component to elephant translocations.
To learn more about how elephant translocations are conducted today, watch Episode 4 of our "Moving Giants" video series, which you can view below. This feature is a companion piece to Episode 4. To see previous episodes in the series, please visit our video hub here.
The hormone surge of testosterone was too much to handle at 15 to 18 years of age. This had spilled over into highly aggressive behavior by these teenage males. And that aggression was vented on their unfortunate white rhino victims.