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.

绝大多数鸣禽都会向成年导师学习鸣唱，这些导师既可以是其亲代雄鸟，也可以是其他同种雄性个体。然而，自然社会情境中调控鸣唱学习的各类变量仍未被充分探明。本研究以家养雄性金丝雀为对象，探究其孵化时间是否会对鸣唱发育以及鸣唱控制系统的神经内分泌参数产生影响。早孵化与晚孵化雄性个体的平均孵化间隔为50天，最大间隔可达90天。成年导师雄鸟的鸣唱活跃度在繁殖季显著下降。早孵化雄性个体在出生后的前99天内平均可接触导师鸣唱，而晚孵化的同龄个体仅在出生后的前48天内能听到成年鸣唱。值得注意的是，尽管季末孵化会对雄性个体的身体状况产生负面影响，但两组雄鸟在鸣唱特征上均未表现出显著差异，无论在秋季还是次年春季。同理，孵化日期并未对鸣唱核团（song nucleus）体积以及循环睾酮水平产生影响。本研究数据表明，晚孵化的雄性个体必然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产生影响。