Experimental Exposure to Noise Affects Hunting Behavior Already From a Young Age in a Nocturnal Acoustic Predator

Abstract

Anthropogenic noise is an increasing form of environmental change that alters natural soundscapes. Human activities, including road traffic, have led to a notable increase in ambient noise, which may impair how animals use their sensory systems to fulfill vital activities. Previous experiments suggest that noise affects the hunting behavior of nocturnal predators, but it is still scarcely documented how the exposure to anthropogenic noise at night affects the behavior of nocturnal animals throughout their growth. Here, we used captive-reared Tawny Owls (Strix aluco), nocturnal raptors relying on hearing to locate prey at night, to test the effect of traffic noise on prey detection at two different ages. Our findings show that noise lowers the rate of prey detection and increases the time needed to locate the prey regardless of the age the owls were tested. Although prey detection improved in older owls (i.e., at the subadult stage), it was still impaired by noise. Moreover, we show that the head-bobbing behavior (i.e., head movements performed to enhance the acoustic localization of a potential prey) was displayed more times by subadults, and it was enhanced by noise regardless of the owls' age. Our study provided new insights about the detrimental effects of noise pollution on the behavior of night-active animals, showing that noise disrupts prey detection already from early life stages, which implies that both young and adult survival may be negatively impacted. Future studies should examine how these results may be relevant for individual fitness and population dynamics in the wild.