School of Biological Sciences, University of Auckland, New Zealand.
Research School of Biology, The Australian National University, Canberra, Australia.
Biol Lett. 2019 Sep 27;15(9):20190257. doi: 10.1098/rsbl.2019.0257. Epub 2019 Sep 4.
Urbanization leads to a rapid and drastic transformation of habitats, forcing native fauna to manage novel ecological challenges or to move. Sexual selection is a powerful evolutionary force, which is sometimes predicted to enhance the ability of species to adapt to novel environments because it allows females to choose high-quality males, but other times is predicted to reduce the viability of populations because it pushes males beyond naturally selected optima. However, we do not know whether or how sexual selection contributes to the likelihood that animals will establish in urban areas. We use a comparative analysis of passerine birds to test whether traits associated with pre- and post-mating sexual selection predict successful colonization of urban areas. We found that plumage dichromatism was negatively associated with urban tolerance, but found no relationship with sexual size dimorphism or testes mass relative to body mass. While we cannot determine the exact reason why species with high plumage dichromatism occur less in cities, it is likely that urban areas increase the costs of expressing bright coloration due, for instance, to dietary constraints, limited male parental care or increased predation.
城市化导致栖息地的快速和剧烈转变，迫使本地动物要么应对新的生态挑战，要么迁徙。性选择是一种强大的进化力量，它有时被预测会增强物种适应新环境的能力，因为它允许雌性选择高质量的雄性，但有时也会降低种群的生存能力，因为它迫使雄性超越自然选择的最佳状态。然而，我们不知道性选择是否以及如何影响动物在城市地区定居的可能性。我们使用雀形目鸟类的比较分析来检验与交配前和交配后性选择相关的特征是否预测动物成功地在城市地区定居。我们发现，羽毛双色性与城市容忍度呈负相关，但与性二型或睾丸质量与体重的比值无关。虽然我们不能确定为什么具有高羽毛双色性的物种在城市中出现的频率较低的确切原因，但由于饮食限制、有限的雄性亲代照顾或增加的捕食等原因，城市地区可能会增加表达鲜艳颜色的成本。
