Wang Yang, Yin Yuan, Ge Shiyong, Li Mo, Zhang Qian, Li Juyong, Wu Yuefeng, Li Dongming, Dudley Robert
Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China.
Department of Integrative Biology, University of California, Berkeley, CA, USA.
PeerJ. 2019 Nov 13;7:e8048. doi: 10.7717/peerj.8048. eCollection 2019.
Although more massive flight muscles along with larger wings, higher wingbeat frequencies and greater stroke amplitudes enhance force and power production in flapping flight, the extent to which these parameters may be correlated with other morphological features relevant to flight physiology and biomechanics remains unclear. Intraspecifically, we hypothesized that greater vertical load-lifting capacity would correlate with higher wingbeat frequencies and relatively more massive flight muscles, along with relatively bigger hearts, lungs, and stomachs to enhance metabolic capacity and energy supply, but also with smaller body size given the overall negative allometric dependence of maximum flight performance in volant taxa. To explore intraspecific correlates of flight performance, we assembled a large dataset that included 13 morphological and kinematic variables for a non-migratory passerine, the Eurasian tree sparrow (). We found that heavier flight muscles and larger wings, heavier stomachs and shorter bills were the most important correlates of maximum load-lifting capacity. Surprisingly, wingbeat frequency, wing stroke amplitude and masses of the heart, lungs and digestive organs (except for the stomach) were non-significant predictor variables relative to lifting capacity. The best-fit structural equation model (SEM) indicated that load-lifting capacity was positively correlated with flight muscle mass, wing area and stomach mass, but was negatively correlated with bill length. Characterization of individual variability in flight performance in a free-ranging passerine indicates the subtlety of interaction effects among morphological features, some of which differ from those that have been identified interspecifically for maximum flight performance in birds.
虽然更发达的飞行肌肉、更大的翅膀、更高的振翅频率和更大的冲程幅度能增强扑翼飞行中的力量和功率输出，但这些参数与其他与飞行生理和生物力学相关的形态特征之间的关联程度仍不明确。在种内，我们假设更大的垂直负载能力与更高的振翅频率、相对更发达的飞行肌肉，以及相对更大的心脏、肺和胃相关，以增强代谢能力和能量供应，但考虑到飞行类群中最大飞行性能的总体负异速生长依赖性，也与更小的体型相关。为了探究飞行性能的种内相关性，我们收集了一个大型数据集，其中包括一种非迁徙性雀形目鸟类——欧亚树麻雀（）的13个形态学和运动学变量。我们发现，更重的飞行肌肉、更大的翅膀、更重的胃和更短的喙是最大负载能力的最重要相关因素。令人惊讶的是，相对于负载能力，振翅频率、翅膀冲程幅度以及心脏、肺和消化器官（除胃外）的质量并非显著的预测变量。最佳拟合结构方程模型（SEM）表明，负载能力与飞行肌肉质量、翅膀面积和胃质量呈正相关，但与喙长呈负相关。对一种自由放养的雀形目鸟类飞行性能个体差异的表征表明，形态特征之间相互作用的微妙性，其中一些与在鸟类种间已确定的最大飞行性能的特征不同。
