Factors most closely explaining activity patterns and behavior of northern saw-whet owls in migratory stopover habitat

Avara, Michael R

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https://hdl.handle.net/2142/129655 Copy

Description

Title

Factors most closely explaining activity patterns and behavior of northern saw-whet owls in migratory stopover habitat

Author(s)

Avara, Michael R

Issue Date

2024-12-19

Director of Research (if dissertation) or Advisor (if thesis)

Ward, Michael P

Committee Member(s)

• O'Keefe, Joy M
• Benson, Thomas J

Department of Study

Natural Res & Env Sci

Discipline

Natural Res & Env Sciences

Degree Granting Institution

University of Illinois Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

saw-whet owl, migration, activity patterns, stopover behavior

Abstract

The northern saw-whet owl (Aegolius acadicus)—hereafter NSWO—is a small migratory owl whose nonbreeding ecology is poorly known. I captured and tagged 43 NSWO from 2022-2023 at Kennekuk County Park in central Illinois—a site used by NSWO as a migratory stopover and wintering location. The goal was to investigate how activity patterns (i.e., movements) in the dusk, dawn, and night were impacted by environmental covariates. Owls were most active at dusk and dawn and on warmer darker nights with light winds and no precipitation earlier in the fall season. NSWO are known to be very quiet during the nonbreeding season and little is known regarding how owls interact. I used automated radio telemetry and acoustic playbacks to determine if NSWO moved towards or away from conspecific vocalizations and recorded any vocal response from the owls. I played vocalizations to radio-tagged owls near an automated radio telemetry stations to determine if the bird moved in response to the playback. NSWO rarely vocally responded to acoustic playbacks (33.3% of the time they vocalized), although birds moved closer to the source of the vocalization. The activity patterns of NSWO appear to parallel those of their rodent prey and it is likely that the covariates that are impacting their activity are also impacting the activity patterns of their prey. While NSWO are not very vocal on the nonbreeding grounds they do appear to respond to conspecific playback by approaching. There is much more to learn about the ecology and behavior of NSWO and research on the behavior of their primary prey (small rodents) and primary threat (barred owls, Strix varia) will likely further our understanding of their movements and vocalizations.

Graduation Semester

2025-05

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/129655

Copyright and License Information

Copyright 2025 Michael Avara

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