Date of Award


Publication Type

Master Thesis

Degree Name



Biological Sciences

First Advisor

Mennill, Daniel (Biological Sciences)


Biology, Ecology.



Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


This thesis provides the first quantitative analysis of Barred Owl (Strix varia) vocalizations and their function. Male and female Barred Owls produce thirteen distinct vocalizations, often combining their calls to perform duets. Female and male calls exhibit distinguishable vocal characteristics useful for sex discrimination. Owls have different diel patterns for different call types and they incorporate specific call types into duets. An experimental playback of neighbour versus stranger owl's duets indicate that Barred Owls used duets to confront territory intruders, but do not discriminate between duets of neighbours versus strangers. Recordings made with a 3.5km transect of automated recording devices demonstrate that nearby owls within the population do not vocalize differently during playback versus silent pre-playback periods. A comparison of Barred Owl calls, duets, and duet behaviour throughout the southeastern United States reveals much variation, but this variation does not follow a consistent geographic pattern.