CLEMSON, South Carolina -- Lions, tigers and ... vampire elephants? Oh, my.
Human-wildlife conflict research has often focused on ways such apex predators as lions, tigers and wolves endanger humans, impact livelihoods and threaten livestock, but a pair of Clemson University researchers has expanded the discussion to include two non-traditional culprits: "vampire elephants" and "ecological zombies."
Better known simply as elephants and hogs than by those macabre monikers, the species are not carnivores traditionally associated with loss of livestock -- nor do they have supernatural powers -- but they can have a similar impact.
New research by Shari Rodriguez and Christie Sampson in the open-access journal PLOS Biology, examines the effects of these less-studied relationships, particularly for feral hogs and elephants, and the potential consequences of excluding these animals from research focused on mitigating wildlife impact on livestock.
"When we deal with livestock issues and human-wildlife conflicts, it's not enough right now to just talk about carnivores," Rodriguez said. "We have to talk about at least hogs and elephants, as well, because there's no reason to reinvent the wheel with (mitigating the impact of) elephants and hogs when we've got a wheel that exists for carnivores that can be applied to at least two other groups of species."
These species can have significant effects on livelihoods by killing young and small livestock and damaging farming infrastructure. They may also affect local communities' perception of the species, which in the case of species of conservation concern, such as elephants, could reduce people's willingness to support conservation initiatives.
Sampson saw the latter scenario -- misconception about a species -- play out right before her eyes during a research trip to Myanmar. An elderly woman had put her store of rice on a platform in a tree to keep it out of the elephants' reach and went to sleep beside it before being killed by what locals believed to be a "vampire elephant."
"She didn't use a tree limb high enough so that, unfortunately, the elephant could reach it," Sampson said. "So the elephant goes to get the rice, takes down the branch, takes her down with it and ends up killing her. When they found the body the next morning, there was no blood because she had been badly injured during the event and lost a great deal into the sandy ground."
It didn't take long for the story to spread that an elephant had killed the woman to drink her blood ... and, as urban legends do, the tall tale spread quickly.
"We heard the story in one village and then we went to an entirely different place and they had the same story that was being passed around -- that a vampire elephant was out killing people to drink their blood," Sampson said. "We tried to tell people, 'They don't eat meat, and they don't drink your blood.' Part of our job is to understand those missing pieces of information for people. Fundamentally, that's not our charge; our charge is the research. But a secondary effect of the research is that we can correct some of those misconceptions as we interact with people and do our work."
But misconceptions can be difficult to dissuade. A couple of years ago when Sampson returned to India, her travel party came across a pile of elephant dung with pieces of human clothing in it. For many locals, the evidence appeared clear: a 'vampire elephant' had claimed another victim.
That was not the case, of course, but it did further underline to the scientists the importance of their research.
"Elephants aren't carnivores, but they still have an effect on people and livestock, and if we can mitigate the conflict to begin with then we don't have issues of 'vampire elephants' or (the belief in) elephants that eat people," Rodriguez said. "If you can mitigate the conflict to begin with, some of these problems will go away."
The publication from Rodriguez and Sampson aims to highlight the importance of including species not traditionally considered in the livestock-protection conversation and finding similarities in how the effects of non-carnivora species can be addressed through the same methodologies as wolves, tigers or lions.
And while vampire elephants don't exist, the threat to livestock is very much real. Both African and Asian elephant species are known to cause livestock injuries and deaths. Livestock owners in elephant ranges perceive elephants as a risk to their livestock, which may reduce their tolerance toward elephants and jeopardize conservation efforts in the area, according to the research.
The Clemson research duo has worked internationally on the topic of human-wildlife conflict with animals such as tigers and elephants, but in the United States, and particularly its Southeast region, feral hogs are much more central to the discussion.
Rodriguez, who serves on the South Carolina Wild Hog Task Force, has often referred to feral hogs as "ecological zombies" because "they will eat anything." The animals are notorious for preying on wildlife and livestock and consuming large amounts of agricultural crops and seeds, sprouts and seedlings, which disrupts reforestation. Their rooting, wallowing and nesting behaviors decrease water quality and promote soil erosion, and they can also spread diseases like pseudorabies and brucellosis, which can spread to humans.
"Though feral hogs may not be of conservation concern, these animals contribute significant losses to farmers' livelihoods. We advocate for the inclusion of noncarnivore species in policies that promote livestock protection because it will allow for better communication regarding effective strategies and more application in the field," the paper reads.
While the scientific community at large had done quite a bit of research on human interactions with apex predators, the scientists realized in reading the existing research it was overlooking a significant portion of the problem it was aimed at addressing.
Rodriguez and Sampson assert that non-predator impact on livestock are a related and equally pressing issue that has received far less attention in the scientific community.
"We ended up writing not a response, but more of an addendum that was a global, larger-scale discussion of how we can prevent wildlife attacks on livestock; herbivores and maybe more non-traditionally considered species should also be part of the conversation because we can learn a lot from the non-carnivore side," Sampson said. "We can learn a lot from them and then we can also share a lot of information to really make a bigger impact overall in the field."