Sex-specific phenotypic integration: endocrine profiles, coloration, and behavior in fledgling boobies

Juan A. Fargallo, Alberto Velando, Isabel López-Rull, Natalia Gañán, Natalia Lifshitz, Kazumasa Wakamatsu and Roxana Torres

Behavioral Ecology, 2014, vol. 25, issue 1, 76-87

Abstract: The intensity of color expression in animals plays a key role in social environments as a mechanism to signal individual capacities in competitive contests. Selective pressures for resource competition differ at different stages of life and between sexes; therefore, coloration is expected to vary between juveniles and adults and between males and females. Exploring the covariance between coloration and other traits may help to understand the functional significance of color and the action of natural selection on multivariate phenotypes. Melanin-based plumage coloration was investigated in the masked booby Sula dactylatra in relation to melanin concentration, sex, hormone levels, and shy–bold behavior of chicks close to fledging. Darker brown boobies showed higher levels of both eumelanin and pheomelanin concentration and lower body mass. Males behaved bolder than females and showed on average 8% larger brown patches. Bolder females had smaller brown patches. Bolder individuals also had lower levels of circulating testosterone, but no differences in corticosterone levels were found. Stronger phenotypic integration was observed in females than males. Our study suggests that juvenile melanic coloration may reflect behavioral strategies by sex, endocrine profiles, and body mass indicating the convergence of different adaptive functions in a given phenotype, this being more evident in females. Direction of correlations differed from those predicted under the pleiotropic idea for color-related traits. These results suggest the possibility that juvenile plumage acts as a signaling system in a social context within the age class and suggest that plumage coloration may indicate different behavioral strategies.

Date: 2014
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://hdl.handle.net/10.1093/beheco/art088 (application/pdf)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:oup:beheco:v:25:y:2014:i:1:p:76-87.

Ordering information: This journal article can be ordered from
https://academic.oup.com/journals

Access Statistics for this article

Behavioral Ecology is currently edited by Louise Barrett

More articles in Behavioral Ecology from International Society for Behavioral Ecology Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK.
Bibliographic data for series maintained by Oxford University Press ().