Predator-induced fear causes PTSD-like changes in the brains and behaviour of wild animals

Sci Rep. 2019 Aug 7;9(1):11474. doi: 10.1038/s41598-019-47684-6.


Predator-induced fear is both, one of the most common stressors employed in animal model studies of post-traumatic stress disorder (PTSD), and a major focus of research in ecology. There has been a growing discourse between these disciplines but no direct empirical linkage. We endeavoured to provide this empirical linkage by conducting experiments drawing upon the strengths of both disciplines. Exposure to a natural cue of predator danger (predator vocalizations), had enduring effects of at least 7 days duration involving both, a heightened sensitivity to predator danger (indicative of an enduring memory of fear), and elevated neuronal activation in both the amygdala and hippocampus - in wild birds (black-capped chickadees, Poecile atricapillus), exposed to natural environmental and social experiences in the 7 days following predator exposure. Our results demonstrate enduring effects on the brain and behaviour, meeting the criteria to be considered an animal model of PTSD - in a wild animal, which are of a nature and degree which can be anticipated could affect fecundity and survival in free-living wildlife. We suggest our findings support both the proposition that PTSD is not unnatural, and that long-lasting effects of predator-induced fear, with likely effects on fecundity and survival, are the norm in nature.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amygdala / physiopathology*
  • Animals
  • Animals, Wild / physiology*
  • Disease Models, Animal
  • Fear / physiology*
  • Female
  • Hippocampus / physiopathology*
  • Humans
  • Male
  • Memory / physiology
  • Passeriformes / physiology*
  • Predatory Behavior
  • Stress Disorders, Post-Traumatic / etiology
  • Stress Disorders, Post-Traumatic / physiopathology*
  • Time Factors
  • Vocalization, Animal