Meeting Abstract

P1.46  Wednesday, Jan. 4  Behavioral and physiological responses to simulated territorial intrusions of short- and long- range song in male dark-eyed juncos (Junco hyemalis) FERGUSON, S.F.*; REICHARD, D.G.; ROSVALL, K.A.; WHITTAKER, D.J.; KETTERSON, E.D.; College of Wooster, Ohio; Indiana University, Bloomington; Indiana University, Bloomington; Michigan State University, East Lansing; Indiana University, Bloomington sferguson12@wooster.edu

Social interactions between conspecifics, such as auditory communication, can have profound impacts on the behavior and physiology of an organism. In songbirds, communication is heavily reliant on song, which can be broadly classified based on differences in amplitude: (1) low amplitude short-range song (SRS), used in close-proximity aggression and courtship displays, and (2) high amplitude long-range song (LRS), important in territory maintenance and mate attraction. SRS and LRS can also differ substantially in structure and complexity and can elicit very different behavioral responses from territorial males. However, whether these song classes differentially affect the physiology of male receivers remains unknown. Thus, we presented free-living male dark-eyed juncos (Junco hyemalis) with simulated territorial intrusions consisting of 10 min of LRS or SRS playback and recorded their behavioral response. Then, 15 minutes after playback ended, we captured each male and collected plasma to measure post-intrusion testosterone (T) levels and assay results are pending. Males spent significantly more time near the speaker and flew significantly less during SRS playback than during LRS playback, indicating a more aggressive response to the SRS intrusion. Differences in both the behavioral and hormonal responses to these two song classes will be discussed in the terms of the perceived threat and function of each song class as well as within the context of the Challenge Hypothesis.