Laboratorio de Biología Evolutiva de Vertebrados, Departamento de Ciencias Biológicas, Universidad de Los Andes, Carrera 1 No. 18 A 10, Bogotá 111711, Colombia.
Colibrí Gorriazul Research Center, Fusagasugá, Cundinamarca 252217, Colombia.
Biol Open. 2024 Nov 15;13(11). doi: 10.1242/bio.060370. Epub 2024 Nov 11.
Hummingbirds are well known for their hovering flight, one of the most energetically expensive modes of locomotion among animals. Molt is a costly event in the annual cycle, in which birds replace their feathers, including all their primary feathers, which, in hummingbirds, comprise most of the area of the wing. Despite this, the effects of molt on hovering flight are not well known. Here, we examined high-speed videos (14 individuals of three species from the Colombian Andes recorded at 1200 frames per second) comparing molting and non-molting hummingbirds' wing kinematics and wingtip trajectories. We found that molting hummingbirds rotated their wings in more acute angles during both downstroke and upstroke compared to non-molting individuals (10° versus 20°, and 15° versus 29°, respectively), while other flight parameters remained unchanged. Our findings show that hummingbirds are capable of sustaining hovering flight and thereby maintaining their weight support even under impressive wing area reductions by adjusting their stroke amplitudes.
蜂鸟以悬停飞行而闻名，这是动物界最耗费能量的运动方式之一。换羽是鸟类年度周期中的一个高成本事件，在此期间，鸟类会更换羽毛，包括所有的初级飞羽，而在蜂鸟中，初级飞羽占据了翅膀的大部分面积。尽管如此，换羽对悬停飞行的影响还不是很清楚。在这里，我们比较了正在换羽和未换羽的蜂鸟的翅膀运动学和翼尖轨迹，通过检查每秒 1200 帧的高速视频（从哥伦比亚安第斯山脉的三个物种中记录的 14 只个体）。我们发现，与未换羽个体相比，换羽蜂鸟在上下拍动翅膀时的旋转角度更大（分别为 10°对 20°和 15°对 29°），而其他飞行参数保持不变。我们的研究结果表明，蜂鸟能够维持悬停飞行，从而通过调整翅膀的拍打幅度，即使在翅膀面积显著减少的情况下，仍能保持其对自身重量的支撑。
