Research has demonstrated that the selective killing, or culling, of elephant herds can have a devastating impact on the social structure of the herd that lasts for decades afterwards. In southern Africa, these effects are most important to note as successful conservation efforts have resulted in robust populations that some are worried will require renewed culling practices to control.
The term culling refers to a process of selectively killing elephants in order to control their population and is separate from poaching. Killing elephants was relied upon for nearly 30 years leading up to 1995, when the practice was abandoned. Discussions about reinstating the practice have arisen because large populations of elephants have a drastic effect on the landscape of an area. Each individual elephant eats up to 400 pounds of food a day, resulting in expanding populations that rip through the land, stripping it of its resources and destroying forest habitats.
Elephants are very intelligent and emotional beings and they live in groups that reflect this. Their social structure is intricate, with herds consisting of extended families of females and young who follow a matriarchal leader. Each group is comprised of several generations. Males typically leave the matriarchal group around the age of 12 and either form their own groups or spend most of their lives alone. The matriarch is usually the oldest elephant in the group, because her experience is key to the survival of the group. It is she that directs the social development of those in her family and provides cues for their behavior that help ensure their survival.
These groups are comprised of close knit families who rely heavily upon their bonds to each other. When a group grows too large, it will split up, allowing the closest related individuals to stay together while the more distantly related break off into their own group. These groups stay close to each other, roaming the same territory and checking in with each other constantly. Sometimes the separate factions come together to create a large group temporarily.
All of this activity relies on the ability of elephants to distinguish between groups that are familiar to them and groups that are foreign. They rely on bonding to develop these social skills. Culling disrupts this crucial social development in elephant herds by breaking up the herds unnaturally which impacts the bonds and bonding process so drastically that decades after the event the herds have still not recovered.
When culling occurs, the matriarch is killed first and the rest of her herd cluster around her. They become easy targets because their dependency on her is so profound that they will not leave her, even if it means their own deaths.
A team of researchers investigated what effects culling had on the herds formed by survivors, and discovered that the elephants whose populations had been selectively murdered for the purpose of population control had experienced disruptions in their social structure that were debilitating to social development. Elephants in these herds did not have the ability to distinguish between age related cues of dominance when presented with the call from a female elephant. Other social skills were also drastically underdeveloped.
The research was conducted using two groups of elephants, a group from Kenya who had not endured culling and a group from South Africa who had. They found significant deficiencies in the South African group of elephants that the Kenyan group did not have. The latter were able to exhibit an organized reaction to the sounds of an unknown female presented to them by freezing, then grouping together and following the matriarch’s lead as they sought out the source of the sounds. The South African group presented no organization in their responses and did not differ in their responses based on age cues indicating dominance or whether or not the call was from a familiar of foreign elephant.
The behavior exhibited by the elephants who survived the culling practices forced upon their families is evidenced in more than just this study. Orphaned elephants are proving to be more erratic and aggressive. Males have been documented to rape and then kill rhinoceroses and there are reports of elephants attacking humans with little to no provocation and with increasing frequency. Some are comparing these changes in behavior to symptoms of post traumatic stress disorder, arguing that the poaching and culling practices of humans, coupled with the social disturbances in the herd have led to humans being perceived as incredibly dangerous animals to elephants.
Culling has not been practiced since 1995 and yet the social ramifications being documented demonstrate that this method of population control significantly impacts elephant herds for decades after the fact. Having no matriarch to lead them means that they have no opportunities to be properly socialized within the group. Bonds are not able to form as deeply, communication is not able to take place as efficiently and the group is not able to organize in the ways that have historically aided their survival. This knowledge is creating quite a quandary for conservations experts who need to consider both the damage large herds inflict on the land as well as the damage sustained by the herd when controlled by culling.
By Vanessa Blanchard