Reacción a "The largest known group of wild chimpanzees splits up and attacks one another, a very rare occurrence"

The study by Sandel and colleagues provides exceptional documentation of the permanent split within a community of wild chimpanzees and the serious conflict that subsequently arises between the two resulting groups. Based on nearly 30 years of continuous observations (which is also exceptional) of the Ngogo community (Kibale National Park, Uganda), it shows how a dynamic initially typical of fusion–fission gives way, starting in 2015, to a progressive process of social polarization that culminates in 2018 with a stable split. This fission is accompanied by social, spatial, and reproductive separation, as well as repeated attacks with a significant demographic impact, including the deaths of several adult males and numerous infants over the course of several years.

From an ethological perspective, changes in social structure are not in themselves extraordinary in chimpanzees, and Jane Goodall’s pioneering studies at Gombe already documented a group split followed by severe aggression. However, what makes this case particularly relevant is the permanent nature of the split and the fact that the conflict is directed against former members of the same group once social boundaries and group identity have been redefined—something extremely rare from an ethological standpoint. Likewise, the use of social network analysis allows for the objective detection of the progressive loss of cohesion and of key individuals acting as social connectors, showing that the rupture is not sudden but rather the result of a cumulative process.

However, as a significant limitation, it should be noted that the study focuses predominantly on the behavior and interactions of males, the primary agents of aggression and territorial defense, while the role of females in the fission process receives much less attention. Given that females participate in key dynamics such as social affiliation, use of space, reproduction, and dispersal, a more in-depth integration of their behavior could provide a more complete picture of the social factors involved in group fragmentation.

These results invite reflection on the role of relational dynamics and social cohesion in the generation of serious internal conflicts, even in the absence of cultural markers, without resorting to deterministic interpretations or simplistic analogies with human violence.