According to a study by behavioral ecologists at the University of Sussex, UK, and published in the journal Frontiers in Zoology, elephants who lost family members to traumatic culling operations decades ago appear to suffer lifelong social impairment.
The Sussex scientists, Graeme Shannon and Karen McComb, led an international team that examined two elephant populations. One was a relatively undisturbed population living in Amboseli National Park, Kenya. The other consisted of animals translocated as calves 20-30 years ago to Pilanesberg Park, South Africa, from Kruger National Park. The latter group had been moved to Pilansesberg after older family members were gunned down in front of them during a managed cull in Kruger—a practice common until the early 1990s.
The research team tested the animals' social understanding by playing recordings of other elephants calls to monitor their response. They found that the Amboseli animals responded appropriately to potentially threatening calls from unfamiliar or dominant elephants: They listened intently, sniffed the air, and if warranted, bunched together in a defensive position. When familiar elephants calls were played, they remained relaxed.
In contrast, the Pilanesberg elephants appeared clueless—in one instance running over a kilometer away at the sound of a familiar elephant; in another, remaining relaxed at the call of an older, strange female. “‘The pattern there was no pattern at all; their reactions were completely random,’” McComb told the journal Science. “‘On the surface, they look like they’re now getting on okay …. But we found a way to go deeper into their minds, and that’s how we found the deficits in the social decisions that they make.’”
Their observations led the research team to conclude that the trauma these elephants experience from the cullings—or, they surmise, from similar poaching massacres—coupled with the inability to learn from family elders, may result in “aberrant behaviours in social animals that are akin to the post-traumatic stress disorder experienced by humans following extremely traumatic events.”