The osteometric identification of castrated reindeer (Rangifer tarandus) and the significance of castration in tracing human-animal relationships in the North

Reindeer are the only domestic cervid and have formed the cosmologies and practical daily lives of numerous peoples in the Northern Hemisphere for thousands of years. The questions of when, how, and where reindeer domestication originated and how it developed remain one of the scientific enigmas of our time. The practice of reindeer castration is an essential feature of all communities practicing reindeer herding today. It has probably been one of the most important interventions in the reindeer’s life cycle and biology that marked the start of domesticating human-reindeer relationships long ago. Castration is and has been essential for reindeer taming, control, training, herd management, and ritual practices. Unsuitably, to this present day, there are no methods zooarchaeologists can employ to distinguish a reindeer gelding from a reindeer bull in the archaeological record. In this current paper, we outline a new method that presents the possibility of differentiating between full males, castrated males, and females based on osteometric features. We measured the leg bones and pelvis of the complete or partial skeletons of 97 adult modern domestic reindeer individuals to determine the precise effects castration has on skeletal size and morphology. We explored our osteometric dataset with different statistical methods. We found a clear separation of the two male groups in the radioulna, humerus, and femur but in the tibia and metapodials to a lesser extent. Osteometric depth and width were generally more affected than the longitudinal axis. Females were easily distinguishable from castrates and full males based on nearly every bone measurement. Our analysis shows that reindeer castration can be proven through osteometric analysis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12520-022-01696-y.