Tree Frogs Alter Their Behavioral Strategies While Landing On Vertical Perches

Abstract

As an arboreal animal, tree frogs face diverse challenges when landing on perches, including variations in substrate shape, diameter, flexibility, and angular distribution, with potentially significant consequences for failed landings. Research on tree frog landing behavior on perches, especially concerning landing on vertical substrates, remains limited. This study investigated the landing strategies (forelimb, abdomen, and hindlimb) of tree frogs on vertical perches, considering perch diameter. Although all three strategies were observed across perches of different diameters, their frequencies differed. Forelimb landing was most common across all perch diameters, with its frequency increasing with perch diameter, while abdomen and hindlimb landing strategies were more prevalent on smaller diameter perches. During the process from take-off to landing, the body axis underwent some deviation owing to the asymmetric movement of the left and right limbs; however, these deviations did not significantly differ among landing strategies. Additionally, different landing strategies led to variations in the landing forces, with abdominal landings generating significantly higher impact forces than the other two strategies. These findings provide insights into the biomechanics and biological adaptations of tree frogs when landing on challenging substrates, such as leaves or branches.

作为树栖动物，树蛙在着陆栖木时面临着基底形状、直径、柔软度和角度分布的多样挑战，着陆失败可能导致严重后果。关于树蛙在栖木上着陆表现的研究尚有限，尤其是在垂直基质上的着陆行为方面。本研究调查了树蛙在垂直栖木上的着陆策略(前肢、腹部和后肢)，并考虑了直径的影响。虽然这三种策略在不同直径的栖木上均有观察到，但其使用频率各不相同。前肢着陆策略在各栖木直径中是最常见的，其频率随着直径的增加而增加，而腹部和后肢着地策略在较小直径的鲈鱼上更为普遍。在从起飞到着陆的过程中，由于左右肢体的不对称运动导致身体轴线发生了一定角度的偏转，但是这些偏转在不同的着陆策略中没有显著性差异。此外，不同的着陆策略导致着陆力的变化，腹部着陆与其他两种着陆策略相比，产生了显著更高的冲击力。这些发现为了解树蛙在叶子或树枝上等有挑战基底着陆时的生物力学和生物适应性提供了参考。