Sex Differences in Fear of Aerial Threats in Foraging Rats: An Ethological Approach

Abstract

Rodents in the wild are under nearly constant threat of aerial predation, and thus haveevolved adaptive innate defensive behaviors, such as freezing or fleeing, in response to aperceived looming threat. Here we investigated sex differences using an ethologically relevant paradigm to study innate-fear of aerial predators in rats during a goal-oriented task. Rats foraging for food in a large arena encountered either a 2D or 3D looming stimulus, to which they instinctively fled back to a safe nest. When facing a direct predatory threat, female rats exhibited a greater fear response than males and this divergence maintained when exposed to the environment on subsequent days with no predator interaction, suggesting stronger contextual fear in female rats. These results closely align with human conditions, where a higher diagnosis rate of fear- and anxiety-related disorders is found in females than in males.