Stroke patterns and regulation of swim speed and energy cost in free-ranging Brunnich's guillemots
Stroke patterns and regulation of swim speed and energy cost in free-ranging Brunnich's guillemots
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DOI：
10.1242/jeb.01331
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发表时间：
2004-12-01
影响因子：
2.8
通讯作者：
Liggins, GA
中科院分区：
文献类型：
--
作者：
Lovvorn, JR;Watanuki, Y;Liggins, GA
在潜水过程中，将记录器安装在自由活动的厚嘴海鸦身上，以测量其游泳速度、身体角度、划水频率、划水和滑行持续时间以及划水过程中的加速度模式，并利用这些数据对推动身体主体（不包括翅膀的头部和躯干）的机械能耗进行建模。在垂直下潜至102 - 135米期间，厚嘴海鸦在下降过程以及大部分上升过程中将速度调节至约1.6 ± 0.2米/秒。划水频率随深度缓慢下降，划水之间很少或没有滑行。从2米到20米深度的整个划水过程中，向上划水和向下划水的向前推力相似，而在更深的深度以及水平游泳时，向下划水的推力要大得多。尽管有这种明显的转变，但这些差异影响较小（<10%），对机械功的估计影响不大。在20米深度时，阻力是这些潜水鸟类机械功的主要组成部分，并且可能通过调节速度使克服阻力所做的功保持在相对较窄的范围内。
Loggers were attached to free-ranging Brunnich's guillemots Uria lomvia during dives, to measure swim speeds, body angles, stroke rates, stroke and glide durations, and acceleration patterns within strokes, and the data were used to model the mechanical costs of propelling the body fuselage (head and trunk excluding wings). During vertical dives to 102-135 m, guillemots regulated their speed during descent and much of ascent to about 1.6 +/- 0.2 m s(-1). Stroke rate declined very gradually with depth, with little or no gliding between strokes. Entire strokes from 2 m to 20 m depth had similar forward thrust on upstroke vs downstroke, whereas at deeper depths and during horizontal swimming there was much greater thrust on the downstroke. Despite this distinct transition, these differences had small effect (20 m, drag is by far the main component of mechanical work for these diving birds, and speed may be regulated to keep work against drag within a relatively narrow range.