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

Abstract

Lay Summary Male birds adjust their strength of response to songs modified with increased amplitude and minimum frequency in the presence of loud human noise. In addition, territorial rival males respond more strongly to louder songs than songs with relatively lower minimum frequencies. Thus, increasing song amplitude can compensate for any loss in signal salience due to shifting songs up in minimum frequency. Increasing only song minimum frequency in the context of high noise levels could be maladaptive.