Elephants that have survived a cull, or witnessed members of their family being poached can suffer from extreme post-traumatic stress disorder, a new study has suggested.
Elephant culls were a conservation tool in South Africa between the 1960s and the 1990s, because park managers worried that too many elephants in a closed area would lead to the destruction of the habitat.
During a cull, helicopters would round up herds of elephants and kill all of them except the youngest. The surviving elephants would then be shipped to different parks.
Scientists have known since the late 1990s that many elephants had psychological damage after seeing their families killed en masse, and it has long been considered as a kind of post-traumatic stress disorder.
However, recent research has revealed that the scale of the impact of violence upon an elephant’s mental wellbeing is far greater than previously anticipated.
Elephants are social animals; the young elephants whose families are poached or culled grow up without the guiding influence of their families often do not learn the necessary skills to survive on their own.
Scientists played the orphaned elephants the sound of an older, dominant, strange female elephant. Naturally socialised elephants would create a defensive formation, however, elephants whose families had been culled did not react to the threat at all.
Mass killings are also likely to have an impact upon the numbers of elephants that are born, as previous studies have shown that herds led by the oldest individuals with the most experience had the highest number of calves.
Richard Connor, a cetacean biologist at the University of Massachusetts, Dartmouth, told ScienceNOW: “It is difficult to not conclude that the legal killing or illegal poaching of elephants is not only inhumane, it is barbaric.”