Functional Analysis of Female Vocalizations in the Brown-headed Cowbird (Molothrus ater)

Chad holding a brown-headed cowbird




Associate Professor

Project Summary

This summer, I worked as a research assistant under the mentorship of Dr. Marc Schmidt and graduate student, Luke Anderson in the Schmidt Lab. The Schmidt Lab is fascinated by the mechanisms underlying songbird behavior and the implications for the understanding of both motor control and social interactions. While in the lab, I was able to work on multiple projects as a way to get a grasp on the different types of research projects available for undergraduates in the lab. I decided to focus on the contextual analysis of female vocalizations in brown-headed cowbirds (Molothrus ater), as there is very little actually known about it.

Animal courtship rituals rely on the coordinated behavior of both males and females. Brown-headed cowbirds partake in courtship behavior in which males direct song displays toward both females and other males. Male song displays involve an approach characterized by a specific posture, followed by a song where the male spreads its wings and bows. Female brown-headed cowbirds produce a vocalization known as the rattle (also known as “chatter”).

With all of this in mind, the goal of my project was to find some correlation between the female “rattle” and the male’s song display. Before the official start of my project, Luke performed focal sampling of female cowbirds in a large semi-naturalistic aviary in the White Lab at Wilfred Laurier University in Ontario, Canada. The females were recorded for ten full uninterrupted minutes every day at the peak of the breeding season (May-June).

My primary responsibility was to go through the videos to analyze and code the context surrounding each individual rattle using Adobe Premiere Pro. A specific code was used for each clip to indicate the interactions that occurred before and after the rattle, resulting in a specific code describing the context of each individually recorded rattle (ex: AB-SB means male approached and sang to the female before the rattle). These codes were compiled into a file, and the data was then analyzed through the use of Python script. My data supports the hypothesis that the “rattle” is antagonistic, as in, the male song display solicits the female to “rattle” in response, however, there is still much to be done in this vein of research.

Throughout my project, I was able to begin learning how to use Python in a laboratory setting to parse through data efficiently, which is definitely a useful skill to retain. I also began to work on building carbon-fiber electrodes for bird surgery, however, this involves a completely separate project altogether. The Schmidt lab did an excellent job training me in different disciplines available in the lab and I am happy to say I will continue to conduct research in the lab after this project. I want to thank the PURM program for allowing me to have such an enjoyable and worthwhile experience.