Food availability is a major ecological factor and affects body condition and sexual traits. Here, we investigated whether males' song behaviour, a trait for female mate choice, was sensitive to the food availability period and its timing in songbirds. We manipulated daily food availability to 4 h in the morning or evening, with controls on food ad libitum, and assessed its effects on song behaviour and forebrain song control system in male zebra finches that were held as adult (parent) or offspring (since birth) at 24 ± 2 °C under 12 h daily photoperiod. Food restriction significantly affected both temporal and spectral features of daily song in offspring, not the parent. In offspring, we found reduced mesor (mean 24-h levels), attenuated amplitude (daily maxima relative to mesor) and altered acrophase (estimated time of daily maxima) of 24-h rhythm, and reduced motif length (in morning-fed), per motif unique syllables and an enhanced song pitch (in evening-fed). There was also a positive correlation of motif length with cheek patch and plasma testosterone levels, and of per motif syllables with cheek patch and daily activity levels in offspring. Among main song controlling forebrain nuclei, LMAN and HVC were reduced in size, and Area X and HVC showed decreased neuronal recruitment in offspring on food restrictions. These results demonstrate the importance of daily food availability and its timing in determining males' sexual signals, and support growing evidence that among vertebrates well-fed males contain reproductive traits that females use for its mate choice.

中文翻译：

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每日食物供应时间对雄性斑马雀鸣曲行为和控制系统神经元可塑性的发育影响。

食物供应是主要的生态因素，会影响身体状况和性特征。在这里，我们调查了男性的歌曲行为（女性择偶的一个特征）是否对食物供应期及其在鸣鸟中的时间安排敏感。我们控制了每天早晨或晚上4小时的食物供应量，随意控制食物，并评估了它们对成年（父母）或后代（出生后）雄性斑马雀的歌曲行为和前脑歌曲控制系统的影响）在每天光照12小时的24±2°C下。食物限制显着影响后代而不是父母的日常歌曲的时间和频谱特征。在后代中，我们发现介面减少（平均24小时水平），每个音节独特音节的音调减弱幅度（相对于中膜的每日最大值）和改变的顶峰相位（每日最大值的估计时间），并且音节长度减小（在早晨进食），每个音节的唯一音节和歌曲音高的提高（在晚间进餐） ）。后代中，花序长度与脸颊斑块和血浆睾丸激素水平呈正相关，每个基音节与脸颊斑块和日常活动水平呈正相关。在主要的控制前脑核的歌曲中，LMAN和HVC的大小减小了，而X区和HVC的后代由于食物限制而减少了神经元募集。这些结果证明了每日食物供应的重要性及其确定男性性信号的时机，并支持越来越多的证据表明，在脊椎动物中，饱食的雄性具有繁殖特征，雌性会利用这种繁殖特征来选择伴侣。