Urban Areas are Associated with Earlier Breeding Timing in American Robins

Authors

Lola Hackle, University of LouisvilleFollow
Jennifer Wickes, University of LouisvilleFollow
Elise Mittlestat, University of LouisvilleFollow
Ashley Stine, University of LouisvilleFollow
Keegan Abeson, University of LouisvilleFollow
Carolina Villalona, University of LouisvilleFollow
Mikus Abolins-Abols, University of LouisvilleFollow

Program/Event

Arts and Research Showcase 2025

Abstract

Climate change and urban environment have been shown to affect bird reproductive timing. In particular, urban development can create the so-called “heat islands” – urban areas that are hotter than the surrounding environment. While the primary cue birds use to time their reproduction is daylength, birds also use temperature as a supplementary cue to fine-tune their reproductive timing. Change in the timing of breeding may impact the survivability of nestlings due to temperature fluctuations and food availability. The American Robin (Turdus migratorius) is a widespread songbird in North American cities and rural areas. We sought to see if urban heating affects the timing of robin nest initiation. We selected 11 locations across the Jefferson County spanning an urban-rural gradient that differed in heat severity. We found a total 65 nests, 25 of which were active. Our preliminary data show that the earliest robin nest in urban areas was initiated 3 weeks earlier than the earliest rural robin nest. Given that robin breeding cycle is around 6 weeks, this represents a significant advance in the timing of breeding in urban areas compared to rural areas.

Recommended Citation

Hackle, Lola; Wickes, Jennifer; Mittlestat, Elise; Stine, Ashley; Abeson, Keegan; Villalona, Carolina; and Abolins-Abols, Mikus (2025) "Urban Areas are Associated with Earlier Breeding Timing in American Robins," The Cardinal Edge: Vol. 3: Iss. 2, Article 5.
Available at: https://ir.library.louisville.edu/tce/vol3/iss2/5