Cross-sectional properties of reindeer long bones and metapodials allow identification of activity patterns

Habitual loading patterns of domesticated animals may differ due to human influence from their wild counterparts. In the early stages of human-reindeer interaction, cargo and draft use was likely important, as well as corralling tame reindeer. This may result to changes in loading as increased (working) or decreased (captive) loading, as well as foraging patterns (digging for lichen from under the snow versus fed working and/or captive reindeer). Our aim is to study whether differences in activity modify variation in bone cross-sectional properties and external dimensions. Our material consists of donated skeletons of modern reindeer: 20 working reindeer (19 racing and one draft), 24 zoo reindeer, and sample of 78 free-ranging/wild reindeer as a reference group. We used general linear modelling to first establish the total variation in cross-sectional properties among wild and free-ranging reindeer, and then to infer how differences in loading modify observed variation among zoo and working reindeer. According to our results, direction of greater bone quantity as well as external dimensions in of radioulna of female reindeer differs from female reference group, likely relating to foraging behavior. External dimensions of humerus differ in working and zoo male reindeer compared to male reference group. Increased robusticity of long bones, especially of tibia among working male reindeer, may indicate increased loading, and increased cortical area of long bones may indicate sedentary lifestyle among female reindeer. The results of this study can be used to understand early stages of reindeer domestication by observing reindeer activity patterns from archaeological material.