The effect of mobbing vocalizations on risk perception in common mynas (Acridotheres tristis)

Abstract

Animals emit predator-elicited calls in response to potential predation threats. These vocalizations induce a variety of anti-predator behaviors in conspecific receivers ranging from moving away from predators (alarm calls) to rallying conspecifics to fend them off (mobbing calls). While much is known about the immediate response to alarm calls, less is known about how mobbing calls influence subsequent antipredator decisions. Mobbing calls stimulate harassment of a potential predator. Therefore we predicted that hearing a mobbing call would make animals less likely to immediately flee an approaching threat. To study the potential effect of mobbing vocalizations on risk assessment, we primed common mynas (Acridotheres tristis) with a series of different stimuli and studied the variation in their subsequent decisions to flee an approaching human by quantifying flight initiation distance (FID). We found that although mynas increased their rate of locomotion after hearing mobbing calls, their subsequent decision to flee was not influenced. We also found that an individual’s propensity to move and look explained some variation in FID. This suggests that while mobbing calls do not influence subsequent decisions to flee, they do affect subsequent behavior.