de Lope F, M Ller A P
Departamento de Ciencias Morfológicas y Biología Celular y Animal, Universidad de Extremadura, E-06071, Badajoz, Spain.
The Galton Laboratory, Department of Genetics and Biometry, University College London, 4 Stephenson Way, London, NW1 2HE, UK.
Evolution. 1993 Aug;47(4):1152-1160. doi: 10.1111/j.1558-5646.1993.tb02142.x.
Sexual selection theory assumes that secondary sexual characters do not influence female reproductive effort. Female animals may invest relatively more in reproduction if they acquire mates of high phenotypic quality, because offspring sired by preferred males may be relatively more viable than offspring sired by less preferred males. Here we report for the first time in a field study that females of the monogamous barn swallow Hirundo rustica adjust their reproductive effort to the attractiveness of their mates. Experimental manipulation of male tail length, which is a trait currently subject to a directional female mating preference, affected the reproductive effort by females in single broods as well as their decision on the seasonal number of clutches. These results, and those of previous experiments, demonstrate that female barn swallows assess the quality of their mates throughout the reproductive season and adjust their reproductive decisions accordingly. This result has important implications for the theory of sexual selection and for the possibility of testing current models of female mate preferences, because the viability of offspring will be confounded by differential reproductive effort.
性选择理论假定第二性征不会影响雌性的繁殖投入。如果雌性动物获得了具有高表型质量的配偶，它们可能会在繁殖方面投入相对更多的精力，因为受青睐的雄性所生育的后代可能比不那么受青睐的雄性所生育的后代具有更高的生存能力。在此，我们首次在一项野外研究中报告，一夫一妻制的家燕（Hirundo rustica）的雌性会根据配偶的吸引力来调整它们的繁殖投入。对雄性尾长进行实验性操控（尾长是目前雌性具有定向交配偏好的一个性状），影响了雌性在单窝中的繁殖投入以及它们对季节性窝数的决定。这些结果以及先前实验的结果表明，雌性家燕在整个繁殖季节都会评估配偶的质量，并据此调整它们的繁殖决策。这一结果对性选择理论以及检验当前雌性配偶偏好模型的可能性具有重要意义，因为后代的生存能力会因不同的繁殖投入而变得复杂。
