Phenotypic trait data play a central role in ecology and evolutionary research. The quality of trait data, and the findings of subsequent analyses, depend on the quality of measurement. However, most studies overlook measurement accuracy in their study designs. We investigated the repeatability of five frequently used linear measurements of avian traits: wing length, tarsus length, bill length, bill depth and bill width and the validity of proxies for three traits: bill surface area, structural body size and tarsus size, using species from the infra-order Meliphagides (honeyeaters, fairy wrens and their allies). Repeatability varied between traits and across species for a given trait: traits larger than 13 mm showed high repeatability compared with smaller traits. By incorporating microCT technology, we showed that the formula for the surface area of a cone, a widely used proxy of bill surface area, accurately describes bill surface area within species. Surface measurement of tarsus and wing lengths were valid proxies for underlying osteology. We recommend preliminary estimation of repeatability should be undertaken for individual traits prior to data collection, in order to design suitable protocols that improve data quality, while optimizing costs involved, particularly for traits < 13 mm.

表型特征数据在生态学和进化研究中起着核心作用。性状数据的质量以及后续分析的结果取决于测量的质量。但是，大多数研究在其研究设计中都忽略了测量精度。我们调查了五个常用的禽类特征线性测量的可重复性：翼长，架长度，比尔长度，比尔深度和比尔宽度，以及三种特性的代理有效性：比表面积，结构体大小和and骨大小，使用物种来自下层的Meliphagides（食蜂鸟，仙女and及其盟友）。对于给定的性状，不同性状之间的重复性各不相同：大于13毫米的性状与较小性状相比具有较高的重复性。通过整合microCT技术，我们表明，圆锥体表面积的公式（一种广泛使用的票据表面积代理）可以准确地描述物种内的票据表面积。骨和机翼长度的表面测量是基础骨学的有效代表。我们建议应在收集数据之前对单个性状进行可重复性的初步估计，以便设计合适的协议以提高数据质量，同时优化相关成本，尤其是对于<13 mm的性状。