Data from: Experimental inhibition of a key cellular antioxidant affects vocal communication

1.There is substantial interest of evolutionary ecologists in the proximate mechanisms that modulate vocal communication. In recent times, there has been growing interest in the role of oxidative stress as a mediator of avian song expression.

2.Here we tested whether the experimental inhibition of the synthesis of a key cellular antioxidant (glutathione) reduces song rate metrics of male European starlings (Sturnus vulgaris). We measured the effect of our treatment on total song rate and on its two components, undirected and nest-box oriented song, outside the breeding season.

3.Treated males that did not own a nest-box (subordinate males likely to be of lower quality) suffered increased oxidative stress relative to untreated males, while treated males that owned a nest-box (dominant males likely to be of higher quality) did not. Treated non-owners also reduced their undirected song rate, whereas treated nest-box owners did not suffer any reduction in song rate.

4.Our results revealed that inhibition of a key cellular antioxidant results in decreased vocal communication in a social vertebrate, and that this effect is dependent on its social status (nest-box owner versus non-owner).

5.This work provides support for the hypothesis that acoustic signals may honestly convey information about the individual oxidative status and capacity to regulate the oxidative balance. Our findings raise the possibility of hitherto unexplored impacts of oxidative stress on fitness traits in social species.

1. 进化生态学家对调控发声通讯的近因机制（proximate mechanisms）有着浓厚的研究兴趣。近年来，学界对氧化应激（oxidative stress）作为鸟类鸣唱表达调节介质的关注与日俱增。
2. 本研究旨在验证：对关键细胞抗氧化剂谷胱甘肽（glutathione）的合成进行实验性抑制，是否会降低雄性欧洲椋鸟（Sturnus vulgaris）的鸣唱频率指标。我们于非繁殖季测量了该处理对总鸣唱频率及其两个组成部分——无指向性鸣唱（undirected song）与朝向巢箱的鸣唱（nest-box oriented song）——的影响。
3. 未拥有巢箱的处理组雄性个体（大概率为质量较低的从属雄性（subordinate males））相较于未处理组雄性，其氧化应激水平有所升高；而拥有巢箱的处理组雄性个体（大概率为质量较高的优势雄性（dominant males））则未出现此现象。此外，未拥有巢箱的处理组个体的无指向性鸣唱频率有所降低，而拥有巢箱的处理组个体的鸣唱频率未出现任何下降。
4. 本研究结果表明，抑制关键细胞抗氧化剂的合成会导致社会性脊椎动物的发声通讯活动减少，且该效应依赖于个体的社会地位（拥有巢箱者与未拥有巢箱者）。
5. 本研究为「声学信号可诚实传递个体氧化状态及调控氧化平衡能力相关信息」这一假说提供了支持。我们的研究结果还提示，氧化应激对社会性物种的适合度性状（fitness traits）存在迄今尚未被探索的潜在影响。