研究发现，相对于自身身体大小，蜂鸟是世界上速度最快的脊椎动物。每秒钟它们能够比其他脊椎动物飞过更多的身体长度。相对于自身的尺寸，蜂鸟甚至比战斗机和航天飞机都飞得快，而且能比战斗机承受更大的地球引力影响。

高速俯冲：蜂鸟求爱礼仪

加州大学伯克利分校的克里斯托弗-詹姆斯-克拉克是一名动物学家，他对雄性蜂鸟俯冲进行了高速拍照。他测量发现，蜂鸟每秒钟飞行385个身体长度，折合27.3米每秒。这是记录到的脊椎动物相对于身体的最高速度。相对于身体大小，比蜂鸟运动速度快的动物是一些昆虫，比如跳蚤。高速俯冲是雄性蜂鸟向雌性蜂鸟求爱的礼仪。

“行为展示是动物求爱的常见现象”，克拉克在今天的《皇家学会学报B》(Proceedings of the Royal Society B)上写道。“仅仅是雌性的喜好就会导致雄性夸张的体征(比如雄性孔雀漂亮的尾巴)，雌性动物对雄性动态行为的喜好会导致雄性接近自己身体极限去完成高难动作。”

承受9倍重力的俯冲

在俯冲时，蜂鸟会承受9倍重力的负荷，这是记录到的脊椎动物在飞行时承受的负荷的最大值。而驾驶战斗机的飞行员在承受7倍重力的负荷时，会短暂性眼前发黑。俯冲飞行是许多鸟类求爱时喜欢用的动作，比如夜鹰、沙锥鸟等等。翠鸟和其他许多海鸟会借助俯冲来捕食。俯冲会使鸟类获得很高的速度。克拉克写道高速俯冲是蜂鸟求爱中的关键环节，而且它还会把尾巴羽毛张开，因为这能产生巨大的短暂的声响，以引起雌性蜂鸟的注意和好感。

蜂鸟的最大速度385身长/秒超过了捕食时游隼俯冲的最高速度200身长/秒和燕子的最高速度350身长/秒。克拉克还写道，蜂鸟的速度比速度最快的战斗机和航天飞机都快。在后然器开启的情况下，战斗机的最高速度可达150身长/秒，航天飞机达到207身长/秒。不过战斗机和航天飞机的绝对速度很大，比如战斗机可达每秒885米，航天飞机达到每秒7700米。

推荐原始出处：

Proceedings of the Royal Society B June 10, 2009, doi: 10.1098/rspb.2009.0508

Courtship dives of Anna's hummingbird offer insights into flight performance limits

Christopher James Clark

Behavioural displays are a common feature of animal courtship. Just as female preferences can generate exaggerated male ornaments, female preferences for dynamic behaviours may cause males to perform courtship displays near intrinsic performance limits. I provide an example of an extreme display, the courtship dive of Anna's hummingbird (Calypte anna). Diving male Anna's hummingbirds were filmed with a combination of high-speed and conventional video cameras. After powering the initial stage of the dive by flapping, males folded their wings by their sides, at which point they reached an average maximum velocity of 385 body lengths s?1 (27.3 m s?1). This is the highest known length-specific velocity attained by any vertebrate. This velocity suggests their body drag coefficient is less than 0.3. They then spread their wings to pull up, and experienced centripetal accelerations nearly nine times greater than gravitational acceleration. This acceleration is the highest reported for any vertebrate undergoing a voluntary aerial manoeuvre, except jet fighter pilots. Stereotyped courtship behaviours offer several advantages for the study of extreme locomotor performance, and can be assessed in a natural context.