Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
Sci Adv. 2017 May 17;3(5):e1603041. doi: 10.1126/sciadv.1603041. eCollection 2017 May.
Birds frequently hop and fly between tree branches to forage. To determine the mechanical energy trade-offs of their bimodal locomotion, we rewarded four Pacific parrotlets with a seed for flying voluntarily between instrumented perches inside a new aerodynamic force platform. By integrating direct measurements of both leg and wing forces with kinematics in a bimodal long jump and flight model, we discovered that parrotlets direct their leg impulse to minimize the mechanical energy needed to forage over different distances and inclinations. The bimodal locomotion model further shows how even a small lift contribution from a single proto-wingbeat would have significantly lengthened the long jump of foraging arboreal dinosaurs. These avian bimodal locomotion strategies can also help robots traverse cluttered environments more effectively.
鸟类经常在树枝间跳跃和飞翔以觅食。为了确定它们双模态运动的机械能权衡，我们用种子奖励四只太平洋鹦鹉，让它们自愿在新的空气动力力台上的仪器栖息之间飞行。通过在双模态跳远和飞行模型中整合对腿部和翅膀力的直接测量以及运动学，我们发现鹦鹉将腿部冲量定向为最小化觅食不同距离和倾斜度所需的机械能。双模态运动模型还展示了即使来自单个原翼拍的微小升力贡献，也会显著延长觅食树栖恐龙的跳远距离。这些鸟类的双模态运动策略还可以帮助机器人更有效地穿越杂乱的环境。
