Natural disaster alters the adaptive benefits of sociality

Abstract Global warming intensifies weather-related disasters that radically alter ecosystems. How animals respond to these abrupt and lasting ecological changes remains poorly understood. Here, we leveraged an unprecedented study of rhesus macaques from 5 years before to 5 years after a category 4 hurricane, which destroyed 63% of the island’s vegetation and exacerbated monkeys’ exposure to intense heat. In response, macaques dramatically and persistently increased tolerance for other monkeys. Social tolerance predicted individual survival after the hurricane–but not before it–by facilitating access to now scarce shade critical for lowering body temperature. We demonstrate that an extreme climatic event altered the adaptive benefits of sociality and triggered substantial and persistent changes in social structure of group-living animals–with consequences for the resilience of populations living in degraded ecosystems. One-Sentence Summary Testard et al. show that natural disasters alter the adaptive benefits of sociality triggering persistent behavioral changes in animals.