Offspring sexual dimorphism and sex-allocation in relation to parental age and paternal ornamentation in the barn swallow

53Citations
Citations of this article
107Readers
Mendeley users who have this article in their library.
Get full text

Abstract

We analysed the morphology of nestling barn swallows (Hirundo rustica) in relation to their sex, and laying and hatching order. In addition, we studied sex-allocation in relation to parentage, parental age and expression of a secondary sexual character of fathers. Molecular sexing was conducted using the sex chromosome-linked avian CHD1 gene. Sex of the offspring was not associated with laying or hatching order. None of nine morphological, serological and immunological variables varied in relation to offspring sex. Sexual dimorphism did not vary in relation to parental age and expression of a paternal secondary sexual character. The proportion of sons declined with brood size. Individual males and females had a similar proportion of sons during consecutive breeding years. The proportion of sons of individual females declined with age, but increased with the expression of a secondary sexual character of their current mate. The generalized lack of variation in sexual dimorphism among nestlings may suggest that barn swallows do not differentially invest in sons vs. daughters. Alternatively, male offspring may require different parental effort Compared to their female siblings in order to attain the same morphological state. The lack of variation in offspring sexual dimorphism with paternal ornamentation suggests no adjustment of overall parental effort in relation to reproductive value of the two sexes. However, male-biased sex ratio among offspring of highly ornamented males may represent an adaptive sex-allocation strategy because the expression of male ornaments is heritable and highly ornamented males are at a sexual selection advantage.

Cite

CITATION STYLE

APA

Saino, N., Ambrosini, R., Martinelli, R., Calza, S., Møller, A. P., & Pilastro, A. (2002). Offspring sexual dimorphism and sex-allocation in relation to parental age and paternal ornamentation in the barn swallow. Molecular Ecology, 11(8), 1533–1544. https://doi.org/10.1046/j.1365-294X.2002.01542.x

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free