Divergent selection on bill morphology contributes to nonrandom mating between swamp sparrow subspecies

作者：Ballentine Barbara^*; Horton Brent; Brown E Tracy; Greenberg Russell

来源：Animal Behaviour, 2013, 86(2): 467-473.

DOI：10.1016/j.anbehav.2013.06.002

• behaviour
• Melospiza georgiana
• morphological evolution
• speciation
• swamp sparrow

Traits subject to ecologically based divergent selection that also affect nonrandom mating (i.e. 'magic traits') may hasten incipient speciation. In this study, we investigated whether nonrandom mating results from ecological divergence between swamp sparrow, Melospiza georgiana, subspecies. As a by-product of adaptive divergence in bill morphology between populations of swamp sparrows, there is a corresponding divergence in features of song shown to be salient to females, potentially providing a mechanism of reproductive isolation. Thus, female mating preferences for song could result in prezygotic isolation that prevents gene flow between subspecies. In this study we tested the hypothesis that female preferences for song provide a mechanism of reproductive isolation that limits gene flow between subspecies. Using copulation solicitation assays, we found that female coastal plain swamp sparrows showed a significant preference for consubspecific songs over heterosubspecific songs. We further tested whether mating preferences in coastal populations explain observed differences in song between subspecies. We found evidence that mating preferences in coastal females may explain the evolution of some acoustic features of song. We suggest that the bill may be an example of a 'magic trait' that contributes to continued divergence of swamp sparrow subspecies.

• 出版日期2013-8