Skip to main content

Data from: The relative response of songbirds to shifts in song amplitude and song minimum frequency


Luther, David A. et al. (2016), Data from: The relative response of songbirds to shifts in song amplitude and song minimum frequency, Dryad, Dataset,


Anthropogenic noise presents a problem for acoustic communication in animal taxa around the world. Many animals respond by modifying their acoustic signals, sometimes along multiple axes, such as song structure, redundancy, or amplitude. To date, no study has assayed the relative response of animals to multiple axes of signal variation, such as song structure and song amplitude, associated with anthropogenic noise levels. To investigate the impact of multiple potential adaptations to anthropogenic noise on targeted receivers, we manipulated song amplitude and song minimum frequency of white-crowned sparrow (Zonotrichia leucophrys) songs. We used a 2 × 2 factorial design of playback experiments to measure male territorial responses to songs that were relatively quiet or loud in relation to typical Z. leucophrys songs and with lower or higher minimum frequencies within the range of natural Z. leucophrys songs. Males responded more strongly to louder songs than to quieter songs and more strongly to lower than to higher minimum frequency songs, with the strongest responses to louder songs with relatively lower minimum frequencies. These results indicate that whether or not increasing amplitude or increasing minimum frequency is more effective at increasing signal transmission distance in anthropogenic noise, increases in signal amplitude increase signal salience in male–male interactions. Thus in the context of territoriality and sexual selection, an increase in song amplitude can compensate for losses in signal salience due to higher minimum frequency. An increase in only song minimum frequency in the context of low frequency anthropogenic noise could be maladaptive.

Usage notes