AVIS-IBIS

Birds of Indian Subcontinent

Sex ratio manipulation within broods of house wrens, Troglodytes aedon

Publication Type:Journal Article
Year of Publication:2000
Authors:Albrecht, DJ
Journal:Animal Behaviour
Volume:59
Issue:6
Date Published:2000
ISBN Number:0003-3472
Keywords:Troglodytes, Troglodytes aedon, Troglodytes troglodytes, Troglodytidae
Abstract:Trivers & Willard (1973, Science, 179, 90-92) developed an economic theory of parental investment to explain how the relative profitability of sons and daughters varies under specific ecological conditions. In their maternal condition hypothesis they proposed that in polygynous species, the sex of an offspring should be associated with the amount of parental care likely to be made available to it. In these species, the amount of parental investment directed towards offspring may differentially influence the fitness of male and female offspring because males in better than average condition as adults may enjoy larger fitness gains than a female would if she were in better than average condition, while the reverse may be true when conditions are poor. I tested this hypothesis by determining the sex of specific offspring within house wren broods. Because hatching is asynchronous and fledging is synchronous in this polygynous species, last-hatched young fledge having received less parental care than their broodmates. I predicted that last-hatched offspring would be more likely to be female. I found that these young were indeed more likely to be females, were more likely to have hatched from last-laid eggs and were fledging in poor condition relative to their broodmates. I propose that female house wrens behave in a manner consistent with the predictions of the Trivers & Willard hypothesis by producing female offspring last in the laying sequence of their clutches.
URL:http://www.sciencedirect.com/science/article/pii/S0003347299914203
Short Title:Animal Behaviour
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith