Bonser R H
Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
J Exp Biol. 1999 Jun;202(Pt 11):1459-63. doi: 10.1242/jeb.202.11.1459.
Many animals use thin perches, such as the branches of trees, as locomotory substrates. In this paper, I have reviewed the literature concerned with measurements of locomotory forces made by birds and primates on thin and flexible substrates. Through a knowledge of the locomotory forces exerted by animals when using different substrates, the mechanical cost of their use can be established. We are just beginning to learn about the magnitude and patterns of force production in various branch-using vertebrates, primarily as a result of the development of instrumented perches. Instrumented perches have been designed to measure the forces produced by birds and primates when leaping from rigid and flexible horizontal and flexible vertical perches, and also from instrumented handgrips during brachiation. The development of these techniques for birds and primates allows us to compare the way in which they use perches as locomotory substrates. In both birds and primates, the magnitudes of landing forces are smaller than those during take-off. Two explanations have been proposed; the difference is either a consequence of perch compliance or it is a strategic decision to be cautious of 'new' perches. Leaps from flexible perches may be somewhat inefficient because considerable energy is dissipated in bending the perch, and this energy may remain unrecovered when the animal leaves contact with the perch.
许多动物将细树枝之类的细栖木用作运动的支撑物。在本文中，我回顾了有关鸟类和灵长类动物在细且柔韧的支撑物上产生的运动力测量的文献。通过了解动物在使用不同支撑物时施加的运动力，可以确定其使用的机械成本。我们才刚刚开始了解各种使用树枝的脊椎动物产生力的大小和模式，这主要是由于仪器化栖木的发展。仪器化栖木旨在测量鸟类和灵长类动物从刚性和柔性水平及柔性垂直栖木上跳跃时，以及在臂行过程中从仪器化握把上跳跃时产生的力。这些针对鸟类和灵长类动物的技术发展使我们能够比较它们将栖木用作运动支撑物的方式。在鸟类和灵长类动物中，着陆力的大小都小于起飞时的大小。对此提出了两种解释；这种差异要么是栖木柔韧性的结果，要么是对“新”栖木保持谨慎的策略性决定。从柔性栖木上跳跃可能效率有点低，因为在使栖木弯曲时会消耗大量能量，而且当动物离开栖木接触时，这些能量可能无法恢复。
