Noise pollution

Research led by Queen’s University Belfast has found that man-made noise changes the signals of animals, hampering their communication with each other. 

The meta-analysis study found animals exposed to human-made noise had to adjust their acoustic signals when competing for mate attraction, to repel rivals and parent-offspring communication, all of which have a crucial role in their survival. 

The study is the first to look at a variety of different species and their response to noise and has been published today (Wednesday 2 December) in Global Change Biology. 

The World Health Organisation has said man-made noise is one of the most hazardous forms of pollution. In many habitats, noise from natural sources that animals are accustomed to is an important evolutionary selective force. In contrast, man-made noise differs from naturally occurring noise because it is typically loud and low in pitch. 

To conduct their study the researchers analysed data from 31 different animal species, such as frogs and birds, gathered from 23 experimental studies that exposed animals to man-made noise. They compared each animal's response to a baseline level, which is often the natural background noise levels in an individual's habitat. 

The researchers studied different components of each species acoustic signals, such as the amplitude (loudness), pitch, rate (how often), and complexity. They found that human-made noise changes the signals of animals, which hampers their communication, disrupting their crucial communication cues with each other. 

These findings have important repercussions for animal communication, for example, man-made noise could limit the correct assessment and change the outcomes of fights as larger individuals producing low-frequency