Wiley C, Fogelberg N, Saether S A, Veen T, Svedin N, Kehlenbeck J Vogel, Qvarnström A
Animal Ecology/Department of Ecology and Evolution, Uppsala University, Norbyvägen, Uppsala, Sweden.
J Evol Biol. 2007 May;20(3):854-64. doi: 10.1111/j.1420-9101.2007.01316.x.
It is well understood that females may gain direct benefits from breeding with attractive males. However, the direct fitness effects of mate-choice are rarely considered with respect to mating between different species (hybridization), a field dominated by discussion of indirect costs of producing unfit hybrid offspring. Hybridizing females may also gain by the types of direct benefits that are important for intraspecific mate choice, and in addition may have access to certain benefits that are restricted to mating with males of an ecologically diverged sister-taxon. We investigate possible direct benefits and costs female Ficedula flycatchers gain from breeding with a heterospecific male, and demonstrate that hybridizing female collared flycatchers (F. albicollis) breed in territories that do not suffer the seasonal decline in habitat quality experienced by females breeding with conspecifics. We exclude the hypotheses that heterospecific males provide alternative food-types or assume a greater amount of the parental workload. In fact, the diets of the two species (F. albicollis and F. hypoleuca) were highly similar, suggesting possible interspecific competition over food resources in sympatry. We discuss the implications of direct fitness effects of hybridization, and why there has been such a disparity in the attention paid to such benefits and costs with regard to intraspecific and interspecific mate-choice.
众所周知，雌性可能会从与有吸引力的雄性交配中获得直接益处。然而，关于不同物种间交配（杂交）的配偶选择的直接适应性影响却很少被考虑，该领域主要讨论的是产生不适应的杂交后代的间接成本。杂交的雌性也可能通过对种内配偶选择很重要的直接益处类型而受益，此外，可能还能获得某些仅限于与生态上有差异的姐妹分类群的雄性交配才能获得的益处。我们研究了雌性斑姬鹟与异种雄性交配可能获得的直接益处和成本，并证明杂交的白领姬鹟（F. albicollis）在领地中繁殖，这些领地不会像与同种雄性交配繁殖的雌性所经历的那样遭受栖息地质量的季节性下降。我们排除了异种雄性提供替代食物类型或承担更多亲代工作量的假设。事实上，这两个物种（F. albicollis和F. hypoleuca）的饮食非常相似，这表明在同域分布中可能存在对食物资源的种间竞争。我们讨论了杂交的直接适应性影响的含义，以及为何在种内和种间配偶选择中，对这种益处和成本的关注存在如此大的差异。
