AVIS-IBIS

Birds of Indian Subcontinent

No evidence of assortative mating on the basis of putative ornamental traits in Long-tailed Finches Poephila acuticauda

Publication Type:Journal Article
Year of Publication:2012
Authors:Van Rooij, EP, Griffith, SC
Journal:Ibis
Volume:154
Issue:3
Date Published:2012
ISBN Number:1474-919X
Keywords:Anas, Anas acuta, bill colour, Dafila, Dafila acuta, Estrildidae, indicator, mutual ornaments, patch size, Poephila, Poephila acuticauda, reproductive success, sexual selection, tail length
Abstract:When multiple ornaments are expressed in both sexes, they are generally assumed to be maintained by mutual sexual selection and have a function in mate choice. In the Long-tailed Finch Poephila acuticauda both sexes exhibit multiple ornaments that vary in their expression in either size (pintail and throat patch) or colour (bill) between individuals and sexes. We assessed whether these ornaments are maintained by mutual sexual selection by exploring whether individuals in a wild population paired assortatively with respect to these ornamental traits, and the degree to which the expression of these ornamental traits was indicative of reproductive success. We found no evidence of assortative pairing with respect to variation in homologous ornaments or body condition in the two sexes. In addition, we found no effect of ornament expression on the reproductive success of either males or females. Our findings suggest that the expression of these apparently ornamental traits in both sexes of this species may play no current role in mutual mate selection or as indicator traits of reproductive performance. We are currently unable to identify any function for these very elaborate ornaments in either sex of this species and suggest that the typical assumption that all such traits have an ornamental function may need further examination.
URL:http://dx.doi.org/10.1111/j.1474-919X.2012.01233.x
Short Title:Ibis
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