There is a statutory requirement to protect certain animals and to assess the environmental effects of new developments on wildlife. However, there is no formal guidance on how such assessments should be undertaken. This research has developed an assessment process specific to animals, which enables informed judgement as to the likely short or long-term impacts. Published animal responses have been analysed to identify particular trends and response thresholds, and a standard procedure for assessing noise effects on animals has been developed. The procedure assigns significance criteria (no effect, slight, moderate and severe) that take account of the physiological and behavioural responses exhibited following exposure to noise. The significance rating determines whether mitigation is required.
Particular combinations of noise, animals and habitat that are especially sensitive to environmental noise are identified as off-road vehicles, helicopters, very quiet habitats, and animals having special hearing characteristics.
An assessment threshold is proposed based on key factors such as the noise level, source distance, and other site-specific circumstances. If LAmax noise levels are greater than 80 dB or the separation between the animals and the noise source is less than 1,000m, an assessment is recommended. For fish and marine mammals, if the Received Level (RL) is greater than 140 dB re: 1μPa rms an assessment is recommended. Slight responses may still arise below these thresholds but moderate or severe responses would not be expected. Circumstances most likely to affect animal responses are a rapid onset of noise, and the presence of helicopters, sonic booms, low flying aircraft, artillery/rockets, blasting/explosions, fireworks, motorboats or float planes.
The assessment methodology is tested on two animal species (black grouse and golden plover) using data from a planning application for military development, and retrospectively to mammals at a wildlife park where low-flying jets had caused moderate/severe responses
