在12月出版的《实验生物学期刊》杂志上，研究人员发表论文"Vocal tract articulation revisited: the case of the monk parakeet"说，科学家用X射线对长尾鹦鹉（Myiopsitta monachus）进行了拍摄，这是一种生活在南美洲的鸟类，它能够被用来训练说话，但却不会变成夸夸其谈的明星。
鹦鹉既没有嘴唇也不长牙齿，但这并不能停止它们准确无误地模仿人类的语言。
如今，研究人员找到了部分原因：像人类一样，鹦鹉也能够利用它们的舌头发音。
在发声时，这种鹦鹉会降低自己的舌头——在它们无法互相看见对方时，便会发出吱吱的“联络呼叫”；而连续的“问候呼叫”则表示出一种社会联系。
研究人员发现，鹦鹉在震动的同时会上下移动它们的舌头。研究人员之前在研究鸟类的发声时从未发现这种移动舌头的情况。
鹦鹉利用它们灵活的、肌肉发达的舌头来探索周围的环境并获得食物。这些能干的器官碰巧有助于鹦鹉向人类发出他们能够理解的问候语。（生物谷bioon.com）
doi:10.1242/jeb.064717
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Vocal tract articulation revisited: the case of the monk parakeet
Verena R. Ohms1,2,*, Gabriël J. L. Beckers3, Carel ten Cate1,4 and Roderick A. Suthers2
Birdsong and human speech share many features with respect to vocal learning and development. However, the vocal production mechanisms have long been considered to be distinct. The vocal organ of songbirds is more complex than the human larynx, leading to the hypothesis that vocal variation in birdsong originates mainly at the sound source, while in humans it is primarily due to vocal tract filtering. However, several recent studies have indicated the importance of vocal tract articulators such as the beak and oropharyngeal–esophageal cavity. In contrast to most other bird groups, parrots have a prominent tongue, raising the possibility that tongue movements may also be of significant importance in vocal production in parrots, but evidence is rare and observations often anecdotal. In the current study we used X-ray cinematographic imaging of naturally vocalizing monk parakeets (Myiopsitta monachus) to assess which articulators are possibly involved in vocal tract filtering in this species. We observed prominent tongue height changes, beak opening movements and tracheal length changes, which suggests that all of these components play an important role in modulating vocal tract resonance. Moreover, the observation of tracheal shortening as a vocal articulator in live birds has to our knowledge not been described before. We also found strong positive correlations between beak opening and amplitude as well as changes in tongue height and amplitude in several types of vocalization. Our results suggest considerable differences between parrot and songbird vocal production while at the same time the parrot's vocal articulation might more closely resemble human speech production in the sense that both make extensive use of the tongue as a vocal articulator.
