Behaviour 2019
The effects of urbanization on the song of a vocal mimic, the gray catbird (Dumetella carolinensis)
Morgan Hussey1, Jennifer To1, T. Brandt Ryder2, Dana Moseley1,2. 1James Madison University, Harrisonburg, Virginia, United States; 2Smithsonian Conservation Biology Institute, Washington, District of Columbia, United States

Urbanization causes changes in ecological communities and noise pollution affecting breeding success and communication of many species. Specifically, urban noise limits signal transmission in animals that signal acoustically. We investigated song and repertoire characteristics of a vocal mimic, the gray catbird (Dumetella carolinensis), across an urban gradient centered in Washington, DC. We hypothesize that urbanization impacts gray catbirds in both song spectral features and in terms of repertoire composition differences. We predict that urban males sing at higher minimum frequencies than rural males and that rural males possess more diverse repertoires than urban males related to the community diversity from which to mimic. To quantify song differences, we measured multiple spectrographic and repertoire parameters of catbird songs. Preliminary analyses support our hypothesis that urban songs have significantly higher minimum frequencies than rural songs. If rural males’ repertoires are larger or, alternatively, composed of more animal-mimicked than anthropogenic sounds compared to urban males this may indicate that community diversity impacts catbirds’ mimicked vocal repertoire.