Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America.
PLoS One. 2013 May 1;8(5):e63239. doi: 10.1371/journal.pone.0063239. Print 2013.
Social experiences can organize physiological, neural, and reproductive function, but there are few experimental preparations that allow one to study the effect individuals have in structuring their social environment. We examined the connections between mechanisms underlying individual behavior and social dynamics in flocks of brown-headed cowbirds (Molothrus ater). We conducted targeted inactivations of the neural song control system in female subjects. Playback tests revealed that the lesions affected females' song preferences: lesioned females were no longer selective for high quality conspecific song. Instead, they reacted to all cowbird songs vigorously. When lesioned females were introduced into mixed-sex captive flocks, they were less likely to form strong pair-bonds, and they no longer showed preferences for dominant males. This in turn created a cascade of effects through the groups. Social network analyses showed that the introduction of the lesioned females created instabilities in the social structure: males in the groups changed their dominance status and their courtship patterns, and even the competitive behavior of other female group-mates was affected. These results reveal that inactivation of the song control system in female cowbirds not only affects individual behavior, but also exerts widespread effects on the stability of the entire social system.
社会经验可以组织生理、神经和生殖功能，但很少有实验准备可以让人们研究个体在构建其社会环境方面的作用。我们研究了棕头牛鹂（Molothrus ater）群体中个体行为和社会动态背后的机制之间的联系。我们对雌性实验对象的神经歌唱控制系统进行了有针对性的失活。回放测试表明，这些损伤影响了雌性对歌曲的偏好：受损的雌性不再对高质量同种歌曲具有选择性。相反，它们对所有牛鹂歌曲都表现出强烈的反应。当受损的雌性被引入混合性别圈养群体时，它们不太可能形成强烈的配对关系，并且不再表现出对优势雄性的偏好。这反过来又通过群体产生了一连串的影响。社会网络分析表明，受损雌性的引入在社会结构中造成了不稳定：群体中的雄性改变了它们的支配地位和求偶模式，甚至其他雌性群体成员的竞争行为也受到了影响。这些结果表明，在雌性牛鹂中失活歌唱控制系统不仅会影响个体行为，还会对整个社会系统的稳定性产生广泛影响。
