Wings as inertia appendages: how bats recover from aerial stumbles
Wings as inertia appendages: how bats recover from aerial stumbles
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DOI：
10.1242/jeb.204255
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发表时间：
2019-10-01
影响因子：
2.8
通讯作者：
Swartz, Sharon M.
中科院分区：
文献类型：
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作者：
Boerma, David B.;Breuer, Kenneth S.;Swartz, Sharon M.
对于许多动物来说，在复杂的自然环境中运动需要进化出能够从意外扰动中恢复的机制。然而，关于飞行动物如何对抗破坏性力量的知识是有限的，对于蝙蝠几乎是不存在的，蝙蝠是唯一能够动力飞行的哺乳动物。我们调查了扰动恢复在大蚊perspicillata管理一个定义明确的压缩空气射流，等于2.5倍体重，这引起了两种类型的干扰，称为空中绊倒：俯仰诱导体扰动和滚转诱导翼扰动。在这两种情况下，蝙蝠的反应主要是通过调整翼关节的延伸，并恢复干扰前的身体方向和左右对称的翅膀运动的过程中，只有一个wingbeat周期。蝙蝠恢复身体的扰动对称地延长他们的翅膀头侧和背上在upstroke，并从机翼扰动不对称地延长他们的翅膀在整个恢复wingbeat。我们用一个简化的动力学模型来检验这样一个假设，即在从滚转引起的扰动中恢复时，机翼伸展的不对称性可以产生惯性力矩，而惯性力矩本身就足以产生所观察到的机体重新定向。结果支持了这一假设，并且还表明，随后恢复对称的机翼伸展有助于通过被动空气动力机制来减缓改出旋转。在恢复过程中，肱骨抬高/压低在很大程度上保持不变，而蝙蝠调整翅膀伸展在手肘和手腕，这表明近端梯度的神经机械控制的翅膀。
For many animals, movement through complex natural environments necessitates the evolution of mechanisms that enable recovery from unexpected perturbations. Knowledge of how flying animals contend with disruptive forces is limited, however, and is nearly nonexistent for bats, the only mammals capable of powered flight. We investigated perturbation recovery in Carollia perspicillata by administering a well-defined jet of compressed air, equal to 2.5 times bodyweight, which induced two types of disturbances, termed aerial stumbles: pitch-inducing body perturbations and roll-inducing wing perturbations. In both cases, bats responded primarily by adjusting extension of wing joints, and recovered pre-disturbance body orientation and left-right symmetry of wing motions over the course of only one wingbeat cycle. Bats recovered from body perturbations by symmetrically extending their wings cranially and dorsally during upstroke, and from wing perturbations by asymmetrically extending their wings throughout the recovery wingbeat. We used a simplified dynamical model to test the hypothesis that wing extension asymmetry during recovery from roll-inducing perturbations can generate inertial torques that alone are sufficient to produce the observed body reorientation. Results supported the hypothesis, and also suggested that subsequent restoration of symmetrical wing extension help to decelerate recovery rotation via passive aerodynamic mechanisms. During recovery, humeral elevation/depression remained largely unchanged while bats adjusted wing extension at the elbow and wrist, suggesting a proximo-distal gradient in the neuromechanical control of the wing.