Stroke and glide of wing-propelled divers: deep diving seabirds adjust surge frequency to buoyancy change with depth
Stroke and glide of wing-propelled divers: deep diving seabirds adjust surge frequency to buoyancy change with depth
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DOI：
10.1098/rspb.2002.2252
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发表时间：
2003-03-07
影响因子：
4.7
通讯作者：
Naito, Y
中科院分区：
文献类型：
--
作者：
Watanuki, Y;Niizuma, Y;Naito, Y
为了提高运动效率，屏气潜水员应该根据浮力随深度的变化来调整他们的向前推力。在野外，Brunnich海鸠（Uria lomvia）深潜时的翅膀推进力是通过鸟载数据记录仪对浪涌（从尾部到头部）和升沉（从腹部到背部）加速度进行高速（32赫兹）采样来测量的。在下降开始时，鸟类在上浮和下浮过程中都产生了频繁的浪涌（3.2 Hz），以达到1.2-1.8 m s（-1）的平均速度，接近预期的最佳游泳速度。当它们下沉得更深时，这些鸟将浪涌的频率降低到2.4赫兹，只在下沉时传递。在上升过程中，他们在18米的深度停止划水，之后游泳速度增加到2.3米每秒（-1），可能是因为随着空气体积的增加浮力增加。在保持恒定的行程持续时间（0.4-0.5秒）的情况下，实现了浪涌频率的平滑变化，可能允许有效的肌肉收缩。
In order to increase locomotor efficiency, breath-holding divers are expected to adjust their forward thrusts in relation to changes of buoyancy with depth. Wing propulsion during deep diving by Brunnich's guillemots (Uria lomvia) was measured in the wild by high-speed (32 Hz) sampling of surge (tail-to-head) and heave (ventral-to-dorsal) accelerations with bird-borne data loggers. At the start of descent, the birds produced frequent surges (3.2 Hz) during both the upstroke and the downstroke against buoyancy to attain a mean speed of 1.2-1.8 m s(-1) that was close to the expected optimal swim speed. As they descended deeper, the birds decreased the frequency of surges to 2.4 Hz, relaying only on the downstroke. During their ascent, they stopped stroking at 18 m depth, after which the swim speed increased to 2.3 m s(-1), possibly because of increasing buoyancy as air volumes expanded. This smooth change of surge frequency was achieved while maintaining a constant stroke duration (0.4-0.5 s), presumably allowing efficient muscle contraction.