Individual age is an important element in models of population demographics, but the limitations of the methods used for age determination are not always clear. We used known-age data from moose (Alces alces), red deer (Cervus elaphus), semi-domestic reindeer (Rangifer tarandus tarandus) and Svalbard reindeer (Rangifer tarandus platyrhynchus) to evaluate the accuracy and repeatability of age estimated by cementum annuli analysis of longitudinally sectioned permanent incisors. Four observers with varying experience performed blind duplicate age estimation of 37 specimens from each cervid. The relationship between known age and estimated age was linear, except for Svalbard reindeer where a quadratic model gave a slightly better fit. After correcting for observer ID and animal ID, there was a slightly declining probability to assess the correct age with increasing age for moose, red deer and Svalbard reindeer. Across cervids and observers, estimated age equalled known age in 69% of all readings, while 95% age ± 1 year. Predicted probability of correct age assessment for experienced observers was 93% for red deer, 89% for Svalbard reindeer, 84% for moose and 73% for semi-domestic reindeer. Regardless of observer experience and cervid, there was a high agreement between repeated assessments of a given animal’s tooth sections. The accuracy varied between cervids but was generally higher for observers with former ageing experience with a given cervid. We conclude that the accuracy of estimated age using longitudinally sectioned incisors is generally high, and even more so if performed by observers with former ageing experience of a given species. To ensure consistency over time, a reference material from known-age individuals for each species analysed should be available for calibration and training of observers.

个体年龄是人口统计模型中的重要元素，但是用于年龄确定的方法的局限性并不总是很清楚。我们使用了驼鹿（Alces alces），马鹿（Cervus elaphus），半驯鹿（Rangifer tarandus tarandus）和斯瓦尔巴德驯鹿（Rangifer tarandus platyrhynchus）的已知年龄数据），以评估通过纵向切开的恒切牙的牙骨质环分析估算出的年龄的准确性和可重复性。四个经验不同的观察者对每个子宫颈的37个标本进行了盲目年龄重复估计。已知年龄与估计年龄之间的关系是线性的，除了斯瓦尔巴德驯鹿（Svalbard reindeer），二次模型的拟合度稍好。校正观察者ID和动物ID后，随着驼鹿，马鹿和斯瓦尔巴德驯鹿年龄的增加，评估正确年龄的可能性略有下降。在所有子宫颈和观察者中，估计年龄等于所有读数的69％为已知年龄，而95％年龄为±1岁。经验丰富的观察者对年龄进行正确年龄评估的预测可能性为：马鹿为93％，斯瓦尔巴德驯鹿为89％，驼鹿为84％，半驯鹿为73％。不管观察者的经验和态度如何，重复评估给定动物牙齿的断面之间都存在很高的共识。宫颈之间的准确度各不相同，但是对于以前具有特定宫颈老化经验的观察者来说，其准确性通常更高。我们得出的结论是，使用纵向切齿的估计年龄的准确性通常很高，如果由具有给定物种的先前衰老经验的观察员进行估算，则准确性更高。为了确保随时间推移的一致性，应该为每个被分析物种提供来自已知年龄个体的参考材料，以进行校准和培训观察员。宫颈之间的准确度各不相同，但是对于以前具有特定宫颈老化经验的观察者来说，其准确性通常更高。我们得出的结论是，使用纵向切齿的估计年龄的准确性通常很高，如果由具有给定物种的先前衰老经验的观察员进行估算，则准确性更高。为了确保随时间推移的一致性，应该为每个被分析物种提供来自已知年龄个体的参考材料，以进行校准和培训观察员。宫颈之间的准确度各不相同，但是对于以前具有特定宫颈老化经验的观察者来说，其准确性通常更高。我们得出的结论是，使用纵向切齿的估计年龄的准确性通常很高，如果由具有给定物种的先前衰老经验的观察员进行估算，则准确性更高。为了确保随时间推移的一致性，应该为每个被分析物种提供来自已知年龄个体的参考材料，以进行校准和培训观察员。