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

Abstract

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.

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

“…Measured parallel to the longitudinal axis cm Measuring box Von den Driesch 1976 Radioulna PL Physiological length of the radius. The longitudinal axis measured from the middle of the lateral ridge of the medial articular facet of the proximal radius to the most distal ridge between the articular surfaces where the radius articulates with the carpal bones cm Curved calipers Niinimäki et al 2021 LI Radioulna Bp Breadth of the proximal end of the radius. Measured from the most lateral process to the most medial process of the proximal radius, i.e., including tubercles mm Small calipers Von den Driesch 1976 Radioulna BFp Greatest breadth of the proximal articular facet of the radius.…”

“…BT is Defined differently by Weinstock 2000a mm Small calipers This study Femur PL Physiological length. Measured between the most proximal point of the femoral caput to the most distal articular surface of the medial condyle, parallel to the longitudinal axis cm Big calipers Niinimäki et al 2021 LI Tibia GL Greatest length. Measured between the most proximal point(s) of the condyle(s) and the most distal projection of the medial malleolus, parallel to the longitudinal axis cm Measuring box Von den Driesch 1976 Tibia Ll Length lateral.…”

“…Greatest length between the central intercondylar eminence of the proximal end to the mid-ridge of the distal articular facet. Measured parallel to the longitudinal axis cm Curved calipers Niinimäki et al 2021 LI Tibia BFp Breadth of the proximal articular facet. Measured between the most medial point of the medial condylar surface to the most lateral point of the lateral condylar surface.…”

“…Measured between the most medial point of the medial condylar surface to the most lateral point of the lateral condylar surface. Measured perpendicular to the longitudinal axis of the tibia mm Small calipers Niinimäki et al 2021 Tibia BFd Breadth of the distal articular facet. The breadth of the articular facet, which articulates with the talus.…”

The Archaeology of Reindeer Domestication and Herding Practices in Northern Fennoscandia

“…Although reindeer have never been kept in complete captivity, apart from zoo-kept individuals, practices such as parttime penning and other human-influenced changes in reindeer mobility patterns may cause skeletal morphology changes. There also are other functional changes such as working that affect skeletal morphology: Bone cross-sectional properties differ between working and non-working reindeer; and working reindeer also tend to be larger and more robust than non-working reindeer, although the latter is a product of the selection of suitable individuals for training, not domestication-related selection pressure (Niinimäki et al 2021;Pelletier et al 2020Pelletier et al , 2021b.…”