Terminal flourishes but not trills differ between urban and rural chaffinch song

Anthropogenic noise interrupts the acoustic communication between animals living in urban habitats. Accumulating evidence suggests that animals can evade this interruption using various strategies such as shifting frequencies upwards or increasing the duration of their signals. In this study, we compared the time and frequency-related characteristics of songs and rain calls of common chaffinches (Fringilla coelebs) inhabiting rural forests and an urban park in Turkey. Most of the song phrases and rain calls did not differ in any of the characteristics measured between urban and rural chaffinches. Terminal flourish phrases of the songs, however, had lower minimum frequencies and broader bandwidth in urban territories, contrary to our predictions. We discuss this finding in relation to its potential adaptive significance.