Date of Graduation

Summer 2022


Master of Science in Biology



Committee Chair

Jay McEntee


Territorial behavior is fundamental for the reproductive success of many species. In many monogamous birds, mated pairs defend year-round territories from conspecifics. Males and females often participate in such interactions in a seemingly cooperative fashion. Furthermore, many of them have developed complex vocal interactions known as duets, in which one member of a pair overlaps its partner’s song in a more or less coordinated fashion, apparently to cooperate in territory defense. However, males and females often respond differently depending on the sex of the intruder; they differ in the degree and mode of aggression displayed during these interactions, and the function of duetting is often unknown due to lack of study or by the overlapping predictions of many of the functions proposed for it. For these species, a thorough understanding of their conspecific territorial behavior entails determining (1) What is the main sex targeted during intrusions by each pair member? (2) How different are sexes in their degree and mode of aggression during territorial interactions? and (3) what are the most likely functions of duetting behavior during intrusions? In this study, an attempt is made to answer these questions using a stereo playback design to study the territorial responses in pairs of Carolina wrens (Thryothorus ludovicianus). My analyses shows that Carolina wrens exhibit a stronger response to same-sex than opposite-sex speakers in duet trials, which females maintain between female and male solo trials in their physical responses, but males maintain in their vocal responses for solo trials. Overall males exhibit more aggressive responses than females, except for female solo trials. Finally, duetting behavior is mostly dominated by females, and their responses are consistent with a mate-guarding function.


territoriality, intrasexual territoriality, birds, stereo playback experiments, duetting behavior

Subject Categories

Behavior and Ethology


© Danny Zapata

Available for download on Saturday, April 22, 2023

Open Access