Anthropogenic Noise and Animal Behaviour: A Review of Effects on Communication, Foraging, Physiology, and Fitness

Abstract

Noise from transport, industry, and resource extraction now pervades terrestrial and aquatic habitats, and a rapidly growing literature shows that it alters the behaviour of animals. This review synthesises published evidence on how anthropogenic noise affects acoustic communication, foraging and antipredator behaviour, physiology, reproduction, and the structure of animal communities. Noise acts through three perceptual mechanisms: masking of signals and cues, distraction, and perception of noise as a threat. Birds, frogs, insects, and whales modify the frequency, amplitude, or timing of their signals in noise, but such adjustments are constrained and can carry costs. Noise reduces the foraging efficiency of acoustic predators, distracts prey, increases vigilance at the expense of feeding, and can raise predation mortality. Chronic exposure is associated with altered glucocorticoid physiology, reduced pairing and hatching success, and smaller broods. Experiments that isolate noise from other disturbance, including playback of traffic noise in roadless habitat, demonstrate that noise alone reduces bird abundance and body condition and can alter pollination and seed dispersal. Responses occur across a wide range of taxa and begin at modest sound levels. However, research remains concentrated on songbirds and marine mammals in Europe and North America, acoustic exposure is often poorly reported, and long-term population consequences are seldom measured. Because noise ceases when its source is removed, it is among the more tractable pollutants. Mitigation options and research priorities are outlined, with attention to under-studied tropical regions.