Data from: Understanding the function of nocturnal song in ovenbirds: males do not countersing at night

Many diurnal bird species vocalize at night, however the function of nocturnal song is, generally, still poorly understood. Previous research has suggested that nocturnal song may serve a social function and is influenced by environmental factors. To test whether males attend to the nocturnal song of conspecifics, we experimentally exposed ovenbirds (Seiurus aurocapilla) to nocturnal flight songs, and recorded their response both during the night and during the following dawn chorus. We compared latency to song and vocal output before and after playback exposure to determine if males altered their vocalizations in response to exposure to flight songs from an unknown male. We found no evidence of counter singing or change in nocturnal song output, nor a change in vocal output during the dawn chorus following playback exposure. Our results suggest that, in ovenbirds, nocturnal song does not serve as an intraspecific social function. Nocturnal song, through rare, may be significant in the mating systems of some diurnal bird species, and requires additional study.诸多昼行性鸟类（diurnal bird）会在夜间鸣唱，但目前学界对其夜间鸣唱（nocturnal song）的功能仍知之甚少。既往研究表明，夜间鸣唱或许具备社会功能，且会受到环境因子的影响。为验证雄性个体是否会响应同种个体（conspecifics）的夜间鸣唱，本研究以灶莺（ovenbird，学名：Seiurus aurocapilla）为实验对象，向其播放夜间飞行鸣唱（nocturnal flight songs），并分别在夜间及次日黎明鸣唱（dawn chorus）时段记录其应答行为。本研究通过比较回放刺激（playback exposure）前后的鸣唱潜伏期（latency to song）与鸣唱输出量（vocal output），以判断雄性灶莺是否会因接触未知雄性的飞行鸣唱而改变其鸣唱行为。实验结果显示，回放刺激后，既未观测到对抗鸣唱（counter singing）行为，亦未发现夜间鸣唱输出量或黎明鸣唱时段鸣唱输出量出现显著变化。本研究结果表明，在灶莺种群中，夜间鸣唱并不具备种内社会功能（intraspecific social function）。尽管夜间鸣唱较为罕见，但它或许在部分昼行性鸟类的交配系统中发挥着重要作用，仍有待进一步深入研究。