Urbanization is one of the fastest-growing threats to the biodiversity of the planet, but not all animals are extirpated by the drastic environmental changes of urbanization, and many are even able to thrive in urban landscapes. Behavioral flexibility is often cited as one reason that successful urban animals can so rapidly adapt to a foreign environment with novel stressors. A well-studied example of urban behavioral flexibility is urban-living birds singing with higher-frequency songs in areas with high levels of traffic noise. The present study investigated this trend in Quiscalus mexicanus, an icterid bird with a huge vocal range, highly sexually selective mating system, and behavioral flexibility, that has become abundant in the rapidly-expanding urban areas of Central America. The peak frequency and syllable count of two different call types were compared between a high-traffic area along the Cinta Costera highway in Panama City, and a low traffic area in the parks of the small, canal-zone town of Gamboa, Panama. One call type showed a significantly higher peak frequency in Panama City, while the other did not, likely be-cause it had a much higher default pitch to begin with. Syllable counts also differed significantly between the sites for both call types but were not consistent in direction of change. These results add a new species and geographical region to the growing literature of pitch up-shifting in urban living birds and provide one explanation for the urban success of Quiscalus mexicanus.
Biodiversity | Bioinformatics | Ecology and Evolutionary Biology | Environmental Monitoring | Ornithology | Urban Studies
Gregory, Benjamin P., "Quiscalus mexicanus vocalization pitch and traffic noise in breeding populations along the Cinta Costera highway and in downtown Gamboa, Panamá" (2019). Independent Study Project (ISP) Collection. 3115.