Birds show tremendous ecological disparity in spite of strong biomechanical constraints imposed by flight. Modular skeletal evolution is generally accepted to have facilitated this, with distinct body regions showing semi-independent evolutionary trajectories. However, this hypothesis has received little scrutiny. We analyse evolutionary modularity and ecomorphology using three-dimensional data from across the entire skeleton in a phylogenetically broad sample of extant birds. We find strongly modular evolution of skeletal element sizes within body regions (head, trunk, forelimb and hindlimb). However, element shapes show substantially less modularity, have stronger relationships to ecology, and provide evidence that ecological adaptation involves coordinated evolution of elements across different body regions. This complicates the straightforward paradigm in which modular evolution facilitated the ecological diversification of birds. Our findings suggest the potential for undetected patterns of morphological evolution in even well-studied groups, and advance the understanding of the interface between evolutionary integration and ecomorphology.

尽管飞行施加了强大的生物力学限制，但鸟类表现出巨大的生态差异。人们普遍认为模块化骨骼进化促进了这一点，不同的身体区域显示出半独立的进化轨迹。然而，这一假设几乎没有受到审查。我们使用来自系统发育广泛的现存鸟类样本中整个骨骼的三维数据来分析进化模块性和生态形态学。我们发现身体区域（头部、躯干、前肢和后肢）内骨骼元素大小的强烈模块化演变。然而，元素形状显示出更少的模块化，与生态学有更强的关系，并提供证据表明生态适应涉及不同身体区域元素的协调进化。这使模块化进化促进鸟类生态多样化的直接范式变得复杂。我们的研究结果表明，即使在经过充分研究的群体中，也可能存在未被发现的形态进化模式，并促进了对进化整合与生态形态学之间界面的理解。