2025/11/21 by Kristen Ruscitelli, Kaiya L. Provost · 2 voices
Biochemistry, Genetics and Molecular Biology · Environmental Science · #Animal Vocal Communication and Behavior #Rangeland and Wildlife Management #Avian ecology and behavior
paper · doi:10.1080/15594491.2025.2583567
Urbanization has been found to impact bird song to facilitate improved auditory communication between conspecifics in areas with increased background noise. Given that song development of brood parasites differs from that of non-parasitic species, it is unclear whether brood parasite vocalizations change in the same manner as those of non-brood parasites in association with urbanization. To investigate if and how urbanization impacts vocalization characteristics of brood parasites, we performed principal component analyses of Brown-headed Cowbird (Molothrus ater) song summary statistics. We used 86 song recordings collected from six Ohio counties between the years of 1948–2000, which were obtained from the Borror Laboratory of Bioacoustics database at Ohio State University. We used linear mixed-effect models to examine relationships between principal components and environmental data obtained from the Anthromes dataset. We found that M. ater vocalizations differ significantly across geographic space and time, in association with changes in urbanization. Year of recording significantly predicted recording length, entropy, and frequency, with vocalizations recorded in later years having longer length of recording, higher entropy, and higher frequency. Additionally, urban occupancy significantly predicted song properties, with vocalizations from areas with increased urban occupancy having higher entropy and wider bandwidths. These findings suggest that urbanization could facilitate changes in M. ater vocalizations over time to promote long-range transmission in urban environments. Additionally, this provides insight into how anthropogenic habitat alteration contributes to acoustic adaptation in birds and allows for increased understanding of how human behavior contributes to altered ecological interactions.