Return to search

Carry-over effects in American redstarts: Implications for sexual selection and behaviour

Migratory birds spend most of the year on the over-wintering grounds or traveling between breeding and wintering areas, but research has focused on the relatively short breeding period. As a consequence, we have only a rudimentary understanding of how life histories of long-distance migrants are shaped by events and selective pressures interacting throughout the annual cycle. In this thesis, I examine the association between plumage traits and performance, both during the over-wintering and breeding phases of the annual cycle and how events during one season carry-over to influence behavioural and evolutionary processes in subsequent seasons in a migratory warbler, the American redstart (Setophaga ruticilla).
First, I demonstrate that tail feather brightness is correlated with winter habitat quality in Jamaica, suggesting that plumage may act as a status signal during the non-breeding season. Stable-carbon isotopes analyzed from claws of redstarts arriving on the breeding grounds confirm the association between ornamentation and winter territory quality. Second, I demonstrate that redstarts arriving to breed in southern Ontario from high-quality winter habitats arrive earlier, resulting in a lower probability of paternity loss, a higher probability of achieving polygyny, and higher genetic fledging success. Third, I demonstrate that tail feather brightness, associated with winter territory quality, predicts the likelihood of polygyny during the breeding season, indicating that tail brightness is associated with performance during two phases of the annual cycle. Paternity is predicted by both tail and flank colouration. Finally, I demonstrate that reported trade-offs between reproductive effort and plumage ornamentation as manifested by moult-migration in redstarts is likely an artifact of high variation in local stable-hydrogen isotope signatures (δD) and occasional feather loss and re-growth during the over-wintering period. Thus, moult-migration does not appear to be an important carry-over effect in redstarts. This work demonstrates that plumage may be under selection during both stationary phases of the annual cycle. Furthermore, it suggests that carry-over effects from the non-breeding season can influence evolutionary processes such as sexual selection and highlights the importance of considering selective pressures and events occurring throughout the annual cycle in studying the behaviour and ecology of migratory animals. / Thesis (Ph.D, Biology) -- Queen's University, 2008-09-21 17:31:31.419

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/1462
Date23 September 2008
CreatorsReudink, MATTHEW
ContributorsQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish, English
Detected LanguageEnglish
TypeThesis
Format2279922 bytes, application/pdf
RightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
RelationCanadian theses

Page generated in 0.0026 seconds