科研之友
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摘要
Parental attractiveness influences paternal and maternal efforts in a wide range of animals that exhibit biparental care. However, we still lack an understanding concerning the direction of the covariance between attractiveness and parental effort, perhaps because studies typically consider only one or a subset of multiple attractiveness signals. In this study we investigated predictions of four hypotheses about the relationship between attractiveness traits (plumage coloration, song and leap display traits) and parental effort (feeding rates) in a wild population of the blue-black grassquit, Volatinia jacarina, a Neotropical sexually dichromatic bird with biparental care. Paternal effort was negatively correlated with male blue-black coloration (UV chroma) and maternal effort was positively correlated with male provisioning rate. Thus, more attractive males relative to the UV chroma are worse fathers relative to less attractive males in this trait. However, female provisioning rate was positively correlated with another male attractive trait: the blue-black plumage coverage. The song, leap display and other features of male coloration were not associated with either male or female parental effort. Taken together, these results support the parental-mating trade-off hypothesis for paternal behaviour, which predicts that attractive males should invest less in current offspring in order to acquire extrapair matings. Also, our results partially support the positive differential allocation hypothesis: although females invested highly in offspring of males with more blue-black plumage coverage, they did not compensate for the low investment of males with UV-shifted blue-black plumage. We highlight the need for future studies to consider multiple sexual traits in order to investigate the relationship between attractiveness and parental investment.
- 出版日期2015-4
