Low frequency dove coos vary across noise gradients in an urbanized environment

• Published in: Behavioural processes Vol. 129; pp. 86 - 93
• Main Authors: Guo, Fengyi, Bonebrake, Timothy C., Dingle, Caroline
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2016
• Subjects: Animals; Anthropogenic noise; Columbidae; Columbidae - physiology; Coo; Environment; Frequency; Hong Kong; Noise; Signals; Sound Spectrography; Urbanization; Vocalization, Animal; Urbanization; Frequency; Coo; Columbidae; Anthropogenic noise; Signals
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/j.beproc.2016.06.002

•We studied very low frequency dove coos across urbanization and noise gradients.•Minimum coo frequencies were highest in noisier habitats.•Maximum coo frequencies were lower in urban habitats than in peri-urban habitats.•Hong Kong doves have higher coo frequencies than those from other parts of their range.•Birds with very low frequency vocalizations alter their signals as a response to urban noise. Urbanization poses a challenge to bird communication due to signal masking by ambient noise and reflective surfaces that lead to signal degradation. Bird species (especially oscines) have been shown to alter their singing behaviour to increase signal efficiency in highly urbanized environments. However, few studies on the effects of noise on song structure have included birds with low frequency vocal signals which may be especially vulnerable to noise pollution due to significant frequency overlap of their signals with traffic noise. We compared the perch coos of spotted doves (Streptopelia chinensis), a species with very low frequency vocalizations, in different background noise levels across urban and peri-urban areas in Hong Kong. We documented a 10% upward shift in the minimum frequency of coos of spotted doves across the noise gradient (a relatively small but significant shift), and a reduced maximum frequency in urban habitats with a higher density of built up area. Hong Kong doves had significantly higher minimum and maximum frequencies than doves from throughout their range (from mostly rural sites). Our results indicate that urban species with extremely low sound frequencies such as doves can alter their vocalizations in response to variable urban acoustic environments.