Data from: Hatching late in the season requires flexibility in the timing of song learning

Most songbirds learn their songs from adult tutors, who can be their father or other male conspecifics. However, the variables that control song learning in a natural social context are largely unknown. We investigated whether the time of hatching of male domesticated canaries has an impact on their song development and on the neuroendocrine parameters of the song control system. Average age difference between early- and late-hatched males was 50 days with a maximum of 90 days. Song activity of adult tutor males decreased significantly during the breeding season. While early-hatched males were exposed to tutor songs for on average the first 99 days, late-hatched peers heard adult song only during the first 48 days of life. Remarkably, although hatching late in the season negatively affected body condition, no differences between both groups of males were found in song characteristics either in autumn or in the following spring. Similarly, hatching date had no effect on song nucleus size and circulating testosterone levels. Our data suggest that late-hatched males must have undergone accelerated song development. Furthermore, the limited tutor song exposure did not affect adult song organization and song performance.绝大多数鸣禽（songbirds）均会通过向成年导师学习来掌握鸣唱技能，这些导师既可以是其亲生父亲，也可以是其他同种雄性个体。然而，在自然社会情境下调控鸣唱学习的各类变量仍未得到充分阐释。本研究旨在探究雄性家养金丝雀的孵化时间是否会对其鸣唱发育以及鸣唱控制系统（song control system）的神经内分泌参数造成影响。早孵化组与晚孵化组雄性个体的平均孵化时间差为50天，最大差值可达90天。成年导师雄性的鸣唱活动在繁殖季期间会出现显著下降。早孵化组雄性在生命最初的平均99天内均可接触到导师鸣唱，而晚孵化组同类仅在生命最初的48天内可听到成年鸣唱。值得注意的是，尽管季节后期孵化会对个体身体状况产生负面影响，但两组雄性个体的鸣唱特征在秋季以及次年春季均未表现出显著差异。同样，孵化日期对鸣唱核团（song nucleus）体积与循环睾酮（testosterone）水平均无显著影响。本研究数据表明，晚孵化组雄性个体大概率经历了加速的鸣唱发育过程。此外，有限的导师鸣唱接触时长并未对成年个体的鸣唱结构与鸣唱表现造成任何影响。