Abstract
Female ornaments in animals with conventional sex roles have traditionally been considered non-functional, being merely a genetically correlated response to selection for male ornamentation. Alternatively, female ornaments may be influenced by selection acting directly on the females, either through female–female competition or male choice. We tested the latter hypothesis in mate choice experiments with bluethroats (Luscinia s. svecica), a passerine bird in which females vary considerably in coloration of an ornamental throat patch. In outdoor aviaries placed in prime breeding habitat, males were allowed to choose between a colourful and a drab female. We found that males associated more with, and performed more sexual behaviours towards, colourful females. Female coloration was not age-related, but correlated significantly with body mass and tarsus length. Thus, we have demonstrated both a male preference for female ornamentation, and a relationship between ornament expression and female body size, which may be indicative of quality. Our results refute the correlated response hypothesis and support the hypothesis that female ornamentation is sexually selected.
Keywords: Coloration Female Ornament Luscinia Svecica Male Mate Choice Sexual Selection Visual Signal
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Selected References
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- Clutton-Brock T. H., Vincent A. C. Sexual selection and the potential reproductive rates of males and females. Nature. 1991 May 2;351(6321):58–60. doi: 10.1038/351058a0. [DOI] [PubMed] [Google Scholar]
- Hamilton W. D., Zuk M. Heritable true fitness and bright birds: a role for parasites? Science. 1982 Oct 22;218(4570):384–387. doi: 10.1126/science.7123238. [DOI] [PubMed] [Google Scholar]
- Lande R., Arnold S. J. Evolution of mating preference and sexual dimorphism. J Theor Biol. 1985 Dec 21;117(4):651–664. doi: 10.1016/s0022-5193(85)80245-9. [DOI] [PubMed] [Google Scholar]
- Nakatsuru K., Kramer D. L. Is sperm cheap? Limited male fertility and female choice in the lemon tetra (pisces, characidae). Science. 1982 May 14;216(4547):753–755. doi: 10.1126/science.216.4547.753. [DOI] [PubMed] [Google Scholar]
- Owens I. P., Thompson D. B. Sex differences, sex ratios and sex roles. Proc Biol Sci. 1994 Nov 22;258(1352):93–99. doi: 10.1098/rspb.1994.0148. [DOI] [PubMed] [Google Scholar]
- Sheldon B. C. Sexually transmitted disease in birds: occurrence and evolutionary significance. Philos Trans R Soc Lond B Biol Sci. 1993 Mar 29;339(1290):491–497. doi: 10.1098/rstb.1993.0044. [DOI] [PubMed] [Google Scholar]
- Zahavi A. Mate selection-a selection for a handicap. J Theor Biol. 1975 Sep;53(1):205–214. doi: 10.1016/0022-5193(75)90111-3. [DOI] [PubMed] [Google Scholar]