Urbanization levels are associated with the start of the dawn chorus in vermilion flycatchers in Colombia

Abstract

Increased urbanization leads to the modification of animal behavior, including the start of the dawn chorus in birds. The beginning of the dawn chorus has been studied in relation to the level of urban noise and nocturnal artificial light in oscine birds, with few studies in suboscines. We evaluated a possible relationship between the start of the dawn chorus and different urbanization levels in a suboscine, the vermilion flycatcher (Pyrocephalus rubinus), in seven locations in the city of Armenia (Colombia). We categorized the urbanization level in each location according to its percentage of built structures, into low and high levels. Observations were made during pre-dawn, starting at 00:00 hr. During each visit we recorded maximum noise levels, artificial light at night (ALAN) and time of first song. Males inhabiting the high urbanization locations started the dawn chorus on average 101 min before sunrise, while males in low urbanization levels did so on average 38 min before. Neither noise level nor ALAN explained this difference. We discuss that, for suboscines, another urban-related factor (ambient temperature) may be a key factor driving the onset of dawn chorus.

KEY WORDS:

• artificial light
• dawn chorus
• Pyrocephalus rubinus
• suboscine
• urban noise
• bird song

Acknowledgements

We are grateful to professors Fernando Vargas Salinas, Luis Hernando Hurtado Tobón, and María Dolly García González for their suggestions in the data analysis. We thank the departments of Universidad del Quindío, Biology warehouse, the Centro de Estudios e Investigaciones en Biodiversidad y Biotecnología de la Universidad del Quindío (CIBUQ), and the Tlaxcala Center for Behavioral Biology at the Universidad Autónoma de Tlaxcala (Mexico) for loaning equipment and supplies. The authors also thank Luz Angélica Sánchez González and Luz Esther González Peralta for their valuable collaboration during fieldwork. We are grateful to Steve Funderburk who kindly checked the English of this paper. We also thank two anonymous reviewers who improved the quality of this paper.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

AUTHOR CONTRIBUTION

Conceived and designed the experiments: K. Sánchez-González, O.A. Aguirre-Obando, and A.A. Ríos-Chelén. Performed the experiments: K. Sánchez-González. Analyzed the data: K. Sánchez-González, O.A. Aguirre-Obando, and A.A. Ríos-Chelén. Contributed materials/analysis tools: K. Sánchez-González, O.A. Aguirre-Obando, and A.A. Ríos-Chelén. Wrote the paper: K. Sánchez-González, O.A. Aguirre-Obando, and A.A. Ríos-Chelén. All authors read and approved the final version of the manuscript.

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed at https://doi.org/10.1080/03949370.2020.1837963