The Effects Of Perceived Predation Risk On The Avian Brain

Predators do not affect prey solely through direct killing. The fear (i.e. the prospect of imminent, violent death) of predators shapes prey ecology– the mere presence of a predator leaves lasting effects. Current models of fear are based on post-traumatic stress disorder (PTSD) in humans. The scientific community has identified brain regions involved in mammalian fear processing. The neurobiological effects of predator fear on wild animals are unknown. I exposed wild black-capped chickadees (Poecile atricapillus) to auditory playbacks simulating acute and chronic predation risk and quantified the expression of short- and long-term immediate-early genes in brain regions implicated in the avian fear network: the nucleus taeniae of the amygdala (TnA), hippocampus (Hp), and caudal nidopallium (NC). The TnA and Hp showed short- and long-term changes in response to predation risk. NC results were ambiguous. I provide new information to be incorporated into the biomedical model of fear and the field of predator-prey ecology