Noise from four types of extractive energy infrastructure affects song features of Savannah Sparrows.

Human activities change the acoustic environment in many settings around the world. These changes are complex, as different anthropogenic sound sources create different acoustic profiles; therefore, some sound sources may have greater impacts on wildlife than others. Animals may adapt to these altered acoustic environments by adjusting their vocalizations. In the case of bird song, this may be achieved by adjusting the whole song, which may preserve the spectral and temporal relationships between successive syllables, or by adjusting components (syllables) within the song. Determining which syllables are adjusted may help to elucidate the mechanisms, benefits, and limitations of song plasticity. We examined the effects of conventional industrial infrastructure used to extract shallow natural gas and petroleum (natural gas compressor stations, generator-powered oil well pumpjacks, power grid--powered oil well screw pumps, and generator-powered oil well screw pumps), compared with quiet control sites, on 15 variables describing the acoustic properties of whole songs and syllables of Savannah Sparrows (Passerculus sandwichensis). Changes in acoustic properties varied with syllable and infrastructure type; most effects occurred at generatorpowered screw pump sites, the loudest type of infrastructure that we studied. We found no effects of infrastructure on whole song variables, but song minimum frequency increased with ambient background noise. We found differing effects of infrastructure type on individual syllable types, with alterations in frequencies, tonalities, and syllable durations. This suggests that some syllables may be more plastic in their response than others, which may allow Savannah Sparrows to adapt their communication in altered acoustic environments. [ABSTRACT FROM AUTHOR]