Data from: Bat species comparisons based on external morphology: a test of traditional versus geometric morphometric approaches

External morphology is commonly used to identify bats as well as to investigate flight and foraging behavior, typically relying on simple length and area measures or ratios. However, geometric morphometrics is increasingly used in the biological sciences to analyse variation in shape and discriminate among species and populations. Here we compare the ability of traditional versus geometric morphometric methods in discriminating between closely related bat species – in this case European horseshoe bats (Rhinolophidae, Chiroptera) – based on morphology of the wing, body and tail. In addition to comparing morphometric methods, we used geometric morphometrics to detect interspecies differences as shape changes. Geometric morphometrics yielded improved species discrimination relative to traditional methods. The predicted shape for the variation along the between group principal components revealed that the largest differences between species lay in the extent to which the wing reaches in the direction of the head. This strong trend in interspecific shape variation is associated with size, which we interpret as an evolutionary allometry pattern.

外部形态学（external morphology）常被用于蝙蝠物种鉴定，以及探究其飞行与觅食行为，此类研究通常依托简单的长度、面积测量指标或比值展开。然而，几何形态测量学（geometric morphometrics）在生物科学领域的应用日益广泛，被用于分析形态变异并区分不同物种与种群。本研究基于翼部、躯体与尾部的形态特征，对比了传统形态测量学方法与几何形态测量学方法区分近缘蝙蝠物种的能力——本次研究对象为欧洲菊头蝠（Rhinolophidae, Chiroptera）。除了对比不同形态测量学方法的性能外，本研究还借助几何形态测量学，将物种间差异以形态变化的形式进行检测。相较于传统方法，几何形态测量学在物种区分上表现更优。基于组间主成分分析的变异预测形态显示，物种间最显著的形态差异在于翼部向头部方向延伸的程度。这种显著的种间形态变异趋势与体型大小相关，我们将其解读为一种进化异速生长（evolutionary allometry）模式。