Laila Yunes-Jiménez

Undergraduate thesis research on female song in the Streak-backed Oriole (Icterus pustulatus)

(Spanish version)

I am studying biology at UNAM (Universidad Nacional Autónoma de México) in Mexico City, and my advisors for my undergraduate thesis project are Dr. Marcela Osorio from UAEM (Morelos University) and Dr. Troy Murphy from Queen's University.


I am very interested in birds and behavioral ecology, especially in the adaptive significance of song. For my thesis research, I am studying the song of the streak-backed oriole (Icterus pustulatus).  The species is incredible because both sexes sing, which is very interesting because females song is far less common than male song, and because females song has not been studied in many species. The motivation behind my study is to understand why females sing (e.g., to attract mates, to defend territories), and to understand if females sing differently from how males sing.

Among streak-backed orioles, the northern subspecies are strongly sexually dichromatic (only males are elaborate), whereas in southern subspecies both sexes are sexually monochromatic elaborate (both are elaborate). Because of both sexes of the southern subspecies defend territories, Drs. Murphy suspects that males and females use plumage signals during territorial conflict, and that this may explain the evolution of elaborate plumage in both sexes. In my study of song, I have a similar hypothesis: because both males and females defend territories, song may function similarly in both sexes to defend territories. Thus, I predict that both sexes sing with similar rates and with similar song complexity. I also predict that seasonal changes in singing will be similar for the sexes.

I am currently working on my undergraduate thesis project in Huautla, a little town in the state of Morelos, Mexico. The study site is in the dry forest of the Sierra de Huautla, with a habitat characterized by deciduous thorn-scrub. My objective is to describe and analyze the vocalizations of males and females during two times of the year: (1) during the pre-breeding season (immediately before clutch initiation), and (2) during the non-breeding season after the chicks have fledged.  By studying vocalizations in these two time periods, I can compare the use of vocal communication by males and females in two extremely different stages of their annual cycle.

Also, this project is going to help Dr. Troy Murphy because with data on songs they can answer more questions about the behavior of the streak-backed oriole, and for this reason this three universities are collaborating on the research.

In the field, I am learning how to conduct a biological study, and have now learned how to net and band birds, how to record vocalizations, and how to systematically record behavior.

I am very excited to report that preliminary results indicate that during the pre-breeding season, females sing much more than males (and that male song is not common)! My investigation into song of the streak-backed oriole is the first study of its kind on this species, and my study is very exciting because it focuses on female song, a phenomenon that is not totally understood.