In a groundbreaking study published in *Science*, researchers have documented what may be the first instance of civil conflict among wild chimpanzees, revealing a striking shift in social dynamics within a once-cohesive group in Uganda’s Kibale National Park. Over the past few years, the Ngogo chimpanzees, one of the largest known wild chimpanzee communities, have experienced a dramatic and violent split, resulting in coordinated attacks and significant loss of life among members of the group.
A Longitudinal Study of Social Dynamics
The research, spearheaded by primatologist Aaron Sandel, draws on over thirty years of meticulous behavioural observations of the Ngogo chimpanzees. Sandel first noted abnormal behaviour among the chimpanzees in June 2015 when he observed signs of anxiety as a cluster of them prepared to encounter other group members. This marked the beginning of a tumultuous period that has culminated in a definitive fracture within the group.
Historically, the Ngogo community had displayed strong social bonds, remaining united from at least 1995 until a critical shift in dynamics occurred around 2015. By 2018, the group had splintered into two distinct factions: the western and central chimpanzees. The resulting conflict has led to at least 24 coordinated assaults by the western group on the central group, resulting in the deaths of at least seven adult males and 17 infants.
Understanding the Causes of Conflict
The study suggests that several factors contributed to this unprecedented division. Social hierarchies within the group were disrupted following the deaths of several influential older individuals, which weakened the connections that had previously bound the community together. In addition, a significant disease outbreak in 2017 may have exacerbated tensions and accelerated the group’s fragmentation.
Sandel highlights an important incident that foreshadowed the conflict: the alpha male’s submissive gesture towards another individual earlier that same day, indicating a shift in power dynamics. “Their abrupt death likely weakened connections among the neighbourhoods, which then made the group vulnerable to this polarisation that happened when the alpha change occurred,” he explained.
Implications for Conservation
The findings of this study carry profound implications for chimpanzee conservation efforts. With these primates already facing the risk of extinction, the emergence of such intra-community violence raises concerns about their social stability. Sandel warns that human activities, such as deforestation, climate change, and disease, could further disrupt social cohesion among chimpanzee communities, potentially leading to more frequent instances of conflict.
Brian Wood, an evolutionary anthropologist at UCLA, emphasises the Darwinian perspective on the conflict, noting that one group can enhance its survival by diminishing the reproductive success of its rivals. The western chimps’ aggressive behaviour has resulted in the central chimps experiencing the lowest survival rates ever documented within a wild community of their species.
Sylvain Lemoine, a biological anthropology professor at the University of Cambridge, remarked on the significance of this research, stating: “This is the first thoroughly reported case of what can be qualified as civil warfare in the species. It underscores that social ties and network connectivity are the foundation of group cohesion, which can be fragile in certain circumstances.”
Why it Matters
The emergence of civil conflict within chimpanzee communities not only challenges our understanding of primate social structures but also raises critical questions about the resilience of animal societies in the face of environmental and social stressors. As humans continue to encroach on natural habitats, the consequences of such disruptions could resonate far beyond the animal kingdom, providing valuable insights into our own societal conflicts. Understanding these dynamics is crucial for developing strategies to protect both chimpanzees and their habitats in an increasingly volatile world.
