Data from: Stress responsiveness in a wild primate predicts survival across an extreme El Niño drought

We know more about the costs of chronic stress than the benefits of the
acute stress response – an adaptive response that buffers organisms from
life-threatening challenges. Yet, no primate study has empirically
identified how the stress response adaptively impacts evolutionary
fitness. Here, we take advantage of a natural experiment – an El Niño
drought – that produced unprecedented mortality for wild white-faced
capuchins. Using a reaction norm approach, we provide evidence from
primates that a more robust stress response to a stressor, measured using
fecal glucocorticoids, predicts a greater likelihood of survival. We show
that individuals with greater stress responsiveness to previous droughts
later had higher survival across a severe El Niño drought. Evolutionary
models need empirical data on how stress responsivity varies in adaptive
ways. While we cannot buffer subjects from catastrophic events, we can use
them to understand which aspects of the stress response help animals to
“weather the storm”.