Epidemics Can Trigger Primate 'Civil Wars'

Longitudinal data from Uganda's Ngogo chimpanzees show that a sequence of adult deaths, a change in the alpha male, and a respiratory epidemic preceded an eight‑year period of factionalization and at least 24 targeted killings. The pattern suggests demographic and health shocks can unravel intergroup ties and produce prolonged, organized intra‑group violence in social primates. — If disease and targeted adult mortality can destabilize primate social networks this way, it affects conservation priorities, disease‑management policy in wild populations, and theories about how similar mechanisms might amplify human intergroup violence after shocks.