Could a centuries-old pastoralist tool help conserve a rare antelope?
By Annabella Helman
In Kenya’s Rift Valley, a pride of lions begins to stir as the sun descends to the horizon and the air grows still. A pastoralist with his 60 cattle, alert to the night’s dangers, begins to usher the herd inside of a large enclosure called a cattle boma. The boma, a centuries-old conflict mitigation tool typically made of branches from the acacia tree, creates a thorny barrier to keep out lions, leopards, and spotted hyenas that might eat, injure, or harass the cattle. Today, some communities use more effective, metal-fenced bomas to protect their livestock from depredation overnight.
Like many ways that people deal with human-wildlife conflict, these bomas work by creating barriers to separate property from wildlife. This method has greatly reduced the immediate problem—large carnivores killing livestock—but new research indicates that cattle bomas have an unintended consequence that threatens the Jackson’s hartebeest, a unique and rapidly declining antelope in central Kenya. Rather than addressing this decline by advising against the use of this crucial human-wildlife conflict mitigation tool or reducing lion numbers, conservationists in Kenya have an opportunity to strategically leverage the cattle boma to conserve lions and their wild prey.
As human populations and affluence escalate, human-wildlife conflict is increasing in both frequency and severity. Direct conflicts, like predators killing livestock and people, get a lot of attention; most solutions, including compensation schemes and predator removal, focus on these unambiguous situations. Indirect conflicts often go unnoticed but can have profound impacts on both wildlife and human communities.
In Laikipia County, located in central Kenya, local people’s main economic activity is herding goats, sheep, and cattle. From the 1950s to 1980s, pastoralists and ranching businesses often killed lions to suppress predator population numbers and their perceived threat to the local cattle economy. But as wildlife tourism in Kenya gained popularity and offered an additional or alternative way to earn a living, local people saw the value in maintaining populations of large predators to encourage tourist dollars. This led to the restoration of lions in the late 1990s.
Concurrently, the growing popularity of multiuse landscapes in conservation, which aim to maintain wildlife populations without disrupting human activities, means that pastoralists are herding livestock on the same landscape where tourists will have their first lion sighting. The increased overlap of wildlife and human activities means more conflict—predominately between livestock and wildlife—which has led to a reliance on cattle bomas across multiuse landscapes.
Recent research has discovered that these bomas create a legacy of impact on the behaviors of wildlife long after they are rotated to new locations or abandoned. In the months that cattle spend their nights fenced inside the bomas, their manure accumulates and fertilizes the area. After the cattle and bomas are gone, the rich soil gives rise to glades—lush lawns of highly nutritious grasses. The grass attracts grazers, especially zebras, that will gather in large numbers within the glades. Lions, who appreciate predictability when hunting, will then seek out these gatherings of zebra for a better chance at their preferred meal. This dynamic, where cattle bomas create hotspots that attract zebras which subsequently attract hungry lions, has an unfortunate consequence for hartebeest.
Jackson’s hartebeest, a hybrid between Coke’s hartebeest and Lelwel hartebeest, only occurs over a small range in central Kenya and is one of the fastest declining antelope species in this region. Researchers have historically attributed this rapid decline to a combination of disease, habitat loss, and predation pressure. Recent work linking predation pressure to bomas and glades could change the way the antelope is conserved.
Dr. Caroline Ng’weno and her team found that when hartebeest, a territorial species, have cattle bomas rotated within 500 meters of their territories, they suffer significantly higher predation rates compared to hartebeest that don’t have cattle bomas near their territories. That’s because hartebeest are fairly easy to hunt, so if they are present at a glade, lions will often favor killing them over the zebras that first drew the lions in.
This finding highlights the unintended consequences of human activities on wildlife, even when those activities are aimed at reducing direct conflicts. It also demonstrates that efforts to mitigate conflict may miss dynamics like these when not taking a holistic view, focusing on single species, and not including humans in the conversation of ecology. The irony lies in the fact that cattle bomas, initially intended to minimize clashes between livestock and wildlife and to reduce retaliatory killing of predators, are inadvertently contributing to the decline of a particularly vulnerable antelope.
However, because this dynamic originates with human intervention, there may be a way to leverage cattle bomas as a tool for conservation. If pastoralists are strategic in planning boma locations away from hartebeest territories, they could help concentrate lion hunting away from this sensitive species, thereby offering a spatial refuge.
This approach would not only engage pastoralists in conservation efforts but also contribute directly to the protection of the rapidly declining hartebeest population in central Kenya. Moreover, this method offers a promising alternative to the traditional approach of reducing predator populations to alleviate pressure on threatened species. By manipulating natural predator-prey interactions, we have the potential to conserve both lions and their prey, striking a balance between the needs of humans and wildlife in shared landscapes. Taking this more holistic approach, which accounts for both direct and indirect impacts of human activities, opens the door to creative solutions grounded in coexistence, not conflict.
Annabella Helman is a PhD Student in the Zoology and Physiology Department at the University of Wyoming under Jake Goheen. Her research focuses on methods of promoting human-wildlife coexistence in Laikipia, Kenya with an emphasis on local-led conservation efforts. Her work will implement an informed boma placement strategy to conserve hartebeest in Kenya.
Header image: Cattle bomas reduce human-wildlife conflict by creating barriers to separate people and their property from wildlife, but a more holistic understanding of the situation indicates that people might leverage their impact on the landscape to support healthy populations of both lions and hartebeest. (Anabella Helman)
