Publication
Title
Maternal yolk testosterone in canary eggs: toward a better understanding of mechanisms and function
Author
Abstract
Maternal yolk androgens in avian eggs have been shown to affect numerous offspring traits. These changes in offspring phenotype represent examples of maternal effects and are thought to adjust offspring development to the posthatching environment. When studying the functional consequences of yolk hormones it is, therefore, crucial to manipulate the yolk androgen concentrations as well as the environmental conditions under which the study is performed. However, so far context-dependent effects of maternal yolk hormones have not sufficiently been taken into account, which might contribute to the current level of inconsistency in yolk androgen-mediated effects. We experimentally elevated the yolk testosterone concentrations and manipulated the sibling size hierarchy. We focused on the effects of yolk testosterone on growth and monitored begging behavior and parental feeding preferences in search of the underlying mechanisms of changes in growth. Experimental changes in the yolk testosterone concentrations significantly affected offspring phenotype. However, elevated yolk testosterone concentrations only improved the growth of chicks that were at a competitive disadvantage, whereas it benefited all chicks when placed in staged competition for food as juvenile. This emphasizes the compensatory role of yolk androgens in the context of hatching asynchrony and its context dependency. Enhanced growth did not coincide with intensified begging. Neither males nor females preferentially fed chicks hatching from eggs with elevated yolk testosterone concentrations. Enhanced growth rather resulted from yolk testosterone induced changes in physiology, of which the detailed mechanisms are yet unknown.
Language
English
Source (journal)
Behavioral ecology / International Society for Behavioral Ecology. - New York, NY
Publication
New York, NY : 2010
ISSN
1045-2249
Volume/pages
21:3(2010), p. 493-500
ISI
000277452800009
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 16.04.2010
Last edited 13.07.2017
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