Data from: Adaptive changes in sexual signaling in response to urbanization

Urbanization can cause species to adjust their sexual displays, as the effectiveness of mating signals is impacted by environmental conditions. Despite many examples showing that mating signals in urban conditions differ from those in rural conditions, we do not know whether these differences provide a combined reproductive and survival benefit to the urban phenotype. Here we show that male túngara frogs have increased the conspicuousness of their calls, which is under strong sexual and natural selection by signal receivers, as an adaptive response to city life. The urban phenotype consequently attracts more females than the forest phenotype, while avoiding the costs imposed by eavesdropping bats and midges, which we show are rare in urban areas. Finally, we show in a translocation experiment that urban frogs can reduce risk of predation and parasitism when moved to the forest, but that forest frogs do not increase their sexual attractiveness when moved to the city. Our findings thus reveal that urbanization can rapidly drive adaptive signal change via changes in both natural and sexual selection pressures.

城市化会促使物种调整其性展示行为，因为交配信号的传递效率会受到环境条件的影响。尽管已有诸多案例表明，城市化环境与乡村环境中的交配信号存在差异，但我们尚不明确这些差异能否为城市表型带来繁殖与生存的双重收益。本研究显示，雄性泡蟾（túngara frog）为适应城市生活，提升了其鸣唱的醒目程度——这类鸣唱同时受到信号接收者的强烈性选择与自然选择压力。因此，城市表型的个体相较于森林表型个体，能吸引更多雌性配偶，同时规避了偷听者蝙蝠和蠓虫带来的生存成本，本研究证实这类天敌在城市区域中极为罕见。最后，我们通过易位实验发现，将城市泡蟾转移至森林环境时，其被捕食与寄生的风险会降低；而将森林泡蟾转移至城市环境时，其性吸引力并未得到提升。综上，本研究结果表明，城市化可通过改变自然选择与性选择压力，快速驱动信号系统的适应性演化。