Document Detail

Maternal androgens in eggs of communally breeding guira cuckoos (Guira guira).
MedLine Citation:
PMID:  16457829     Owner:  NLM     Status:  MEDLINE    
Variation of maternal androgens in avian eggs may be a mechanism of maternal influence on offspring development, growth, and/or behavior. We studied yolk androgen concentrations in eggs of guira cuckoos (Guira guira) to understand how females might enhance the success of offspring in a complex communal breeding system. We measured concentrations of androstenedione, 5alpha-dihydrotestosterone, and testosterone in yolks and identified eggs and clutches of individuals in joint nests by yolk protein electrophoresis. Androstenedione had the highest yolk concentration, at least 10 times higher than that of testosterone and 5alpha-dihydrotestosterone. The first eggs of individual females that laid two or three eggs in a joint nest had lower androstenedione concentrations than their second and third eggs, the latter having a lower probability of being ejected from the nest. This implies that guira cuckoo females may influence offspring survival and competitiveness in communal nests by means of differential allocation of androstenedione and laying tactics. There was significant variation in yolk androstenedione among females, but the order in which females entered laying in the communal clutch had no effect on the concentrations. Androstenedione yolk concentrations increased with communal clutch size, which may indicate that higher levels of competition in larger groups lead to higher yolk androgen concentrations. Finally, androstenedione concentrations were higher in clutches in the later wetter periods of the rainy season than during the earlier drier period. This may be explained by the high frequency of large clutches in the later periods, with more females contributing to a joint clutch.
Mariana O Cariello; Regina H F Macedo; Hubert G Schwabl
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-02-02
Journal Detail:
Title:  Hormones and behavior     Volume:  49     ISSN:  0018-506X     ISO Abbreviation:  Horm Behav     Publication Date:  2006 May 
Date Detail:
Created Date:  2006-05-08     Completed Date:  2006-07-31     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0217764     Medline TA:  Horm Behav     Country:  United States    
Other Details:
Languages:  eng     Pagination:  654-62     Citation Subset:  IM    
Departamento de Ecologia, Universidade de Brasilia, Brasilia, DF 70910-900, Brazil.
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MeSH Terms
Androgens / metabolism*
Androstenedione / metabolism
Birds / physiology*
Dihydrotestosterone / metabolism
Egg Yolk / metabolism*
Maternal Behavior / physiology
Nesting Behavior / physiology*
Reproduction / physiology
Social Behavior
Testosterone / metabolism
Reg. No./Substance:
0/Androgens; 521-18-6/Dihydrotestosterone; 58-22-0/Testosterone; 63-05-8/Androstenedione

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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