Feeding mechanisms: Hummingbird jaw bends to aid insect capture
Feeding mechanisms: Hummingbird jaw bends to aid insect capture
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喂食机制：蜂鸟下巴弯曲以帮助捕获昆虫
作者：
C. Dickman;C. Huang
与许多四足动物的上颌不同，鸟类的上颌相对于头骨移动，并且通常沿其长度灵活，而下颌（下颌骨）通常是由几块骨头融合形成的刚性结构，仅在与头骨相交的地方弯曲。在这里，我们描述了蜂鸟以前未被注意到的下颌弯曲运动，其中下颌骨的远端主动向下弯曲，并且张开张开以捕捉飞行的昆虫。人们认为蜂鸟进化出了又长又窄的喙，因为它专门以花蜜为食，但蜂鸟需要用昆虫来补充其饮食，这肯定是其下颌具有令人惊讶的灵活性的原因之一。
The upper jaws of birds, unlike those in many tetrapods, move relative to the skull and are often flexible along their length, whereas the lower jaw (mandible) is usually a rigid structure formed by the fusion of several bones, flexing only where it meets the skull. Here we describe a previously unnoticed mandibular bending movement in hummingbirds, in which the distal half of the mandible is actively flexed downwards and the gape widens to catch flying insects. The hummingbird is thought to have developed a long narrow bill as it specialized in feeding on floral nectar, but the bird's need to supplement its diet with insects must have contributed to the surprising flexibility of its jaw.