Data from: Validating methods for estimating endocranial volume in individual red deer (Cervus elaphus)

Comparing brain sizes is a key method in comparative cognition and evolution. Brain sizes are commonly validated by interspecific comparisons involving animals of varying size, which does not provide a realistic index of their accuracy for intraspecific comparisons. Intraspecific validation of methods for measuring brain size should include animals of the same age and sex to ensure that individual differences can be detected in animals of similar size. In this study we compare three methods of measuring the endocranial volume of 33 red deer skulls to investigate the accuracy of each method. Methods for estimating endocranial volume included scanning each skull using computerised tomography (CT) and quantifying the volume with OsiriX software, filling the cranium with glass beads and measuring the bead volume, and linear measurements (length, width, and height) of the cranium using calipers. CT scan volumes were highly correlated with results from the bead method, but only moderately correlated with the linear method. This study illustrates the importance of validating intraspecies measurement methods, which allows for the accurate interpretation of results.脑容量比较是比较认知学与进化研究中的核心方法之一。当前学界通常通过种间比较来验证脑容量测量方法的有效性，但此类比较选取的动物体型各异，无法为种内比较的方法准确性提供贴合实际的评估指标。若要对脑容量测量方法开展种内验证，需选取年龄与性别均一致的实验动物，以确保能够在体型相近的个体中检测出个体差异。本研究针对33个马鹿颅骨的颅腔容积测量，对比了三种不同方法，以评估各方法的准确性。本次研究所采用的颅腔容积估算方法包括：利用计算机断层扫描（CT）对每具颅骨进行扫描并通过OsiriX软件量化容积、向颅腔内填充玻璃珠并测量珠体总容积，以及使用游标卡尺测量颅骨的长度、宽度与高度三项线性参数。CT扫描所得的颅腔容积与玻璃珠法的测量结果呈高度相关，但仅与线性测量法呈中度相关。本研究充分彰显了种内测量方法验证的重要性，可为相关研究结果的精准解读提供可靠支撑。