Vocalization behavior of captive loggerhead shrikes was studied at the Avian Science and Conservation Centre of McGill University. In the first stage, calls of two pairs kept in indoor cages were individually recorded not only to catalogue these calls spectrographically and quantitatively but also to use them in identifying the birds sexually. Males vocalized 21 call figures for 16.50% of the observation time and females, 8 call figures for 2.64% of the observation time. Males contiguously delivered 1 to 11 bouts with a mean of 7.25 min for a rate of 6.06 bouts/h; females delivered 1 to 9 bouts with a mean of 4.07 min for a rate of 1.27 bouts/h. Males not only vocalized at a higher rate and longer than females, but also demonstrated trill calls which the females did not do. In the second stage, five pairs were paired in large outdoor breeding pens. Their calls were recorded and current visual displays observed in an effort to understand calls related to breeding behaviors. Two new calls figures vocalized by males as well as 2 call figures by young shrikes were recorded. Each male demonstrated distinctive calls that differed from those of other males during nest-site selection, nest building and copulation, but similar calls during food offering, aggressive and alarm behavior. Despite the call differences, all males performed similar visual displays during the above activities. Conversely, breeding females gave no calls, other than harsh calls during food offering, food begging, aggressive and alarm behaviors.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.23427 |
| Date | January 1995 |
| Creators | Soendjoto, Mochamad Arief |
| Contributors | Bird, D. M. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Natural Resource Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001487458, proquestno: MM12274, Theses scanned by UMI/ProQuest. |
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