Data from: Experimentally provided conspecific cues boost bird territory density but not breeding performance

Decision-making during different life history stages requires information, which is obtained through own or others’ experience and interaction with the environment. In birds, song is important for territory defense and mate attraction. While song has evolved to purposely convey information it can be inadvertently exploited by conspecifics. Experiments attempting to attract focal species by playing back their song are numerous, yet the consequences for reproductive performance remain little understood. In 2013 and 2014, settlement, reproduction and extra-pair paternity of Phylloscopus sibilatrix were assessed in a randomized experiment. We hypothesized that territory number, reproductive performance and extra-pair paternity would be higher on song plots (wood warbler song playbacks during pre-breeding periods) than control plots (no wood warbler song playback). On song plots, three times more territories were established, settlement occurred faster and maximum plot occupancy was higher compared to control plots. Pairing rate, daily nest survival rate, mean clutch size, mean number of nestlings and fledglings, rates of extra-pair young, nest abandonment, and nest predation did not differ between treatments, but fledging success was lower on song plots compared to control plots. This study shows the important role social cues can play for territory selection of birds, but also exemplifies the necessity for post-attraction evaluation of reproduction to rule out negative effects of artificial attraction. Decreased fledging success on song plots and ambiguity about consequences of artificial attraction for distribution and settling dynamics of the species give reason to further evaluate whether acoustic attraction represents a suitable method for songbird conservation.生物在不同生活史阶段开展决策时需依托信息，此类信息可通过自身或同类的经验、与环境的交互获取。在鸟类中，鸣唱对于领域防御与配偶吸引至关重要。尽管鸣唱演化的核心目的是主动传递信息，但却可能被同种个体无意利用。目前已有大量通过回放鸣唱以吸引目标物种的实验，但学界对这类操作对目标物种繁殖表现的影响仍知之甚少。本研究于2013年与2014年开展随机对照实验，评估了林柳莺（Phylloscopus sibilatrix）的领域定居、繁殖表现以及额外配对父权（extra-pair paternity）情况。我们提出研究假设：相较于对照样地（不播放林柳莺鸣唱），鸣唱播放样地（繁殖前期回放林柳莺鸣唱）的领域数量、繁殖表现以及额外配对父权比例均会更高。实验结果显示，鸣唱播放样地的领域建立数量为对照样地的三倍，领域定居速度更快，样地最大容纳量也显著更高。两组处理间的配对率、每日巢存活率、平均窝卵数、平均雏鸟数与离巢幼鸟数、额外配对幼鸟比例、弃巢率以及巢捕食率均无显著差异，但鸣唱播放样地的离巢成功率显著低于对照样地。本研究不仅证实了社会线索在鸟类领域选择中发挥的重要作用，同时也凸显了开展吸引后繁殖效果评估的必要性，以排除人工吸引带来的潜在负面影响。鸣唱播放样地的离巢成功率下降，以及人工吸引对该物种种群分布与定居动态的影响尚不明确，均提示我们需进一步评估声学吸引是否可作为鸣禽保护的适宜手段。