Ontogenetic Scaling of Fore- and Hind Limb Posture in Wild Chacma Baboons (Papio hamadryas ursinus)

摘要: Large-scale interspecific studies of mammals ranging between 0.04–280 kg have shown that larger animals walk with more extended limb joints. Within a taxon or clade, however, the relationship body size and joint posture is less straightforward. Factors may affect lack congruence broad narrow phylogenetic analyses kinematics include limited sampling (1) ranges size, and/or (2) numbers individuals. Unfortunately, both issues are inherent in laboratory-based zoo locomotion research. In this study, we examined mass elbow knee angles (our proxies fore- hind posture, respectively) cross-sectional ontogenetic sample wild chacma baboons (Papio hamadryas ursinus) habituated De Hoop Nature Reserve, South Africa. Videos were obtained from 33 individuals known age (12 to ≥108 months) (2–29.5 kg) during walking trials. Results show older, heavier significantly joints but not This pattern consistent when examining only males, within female sample. Heavier, older also display variation their compared lighter, young animals. Thus, single primate species spanning an order magnitude mass, exhibited postural scaling phenomenon while forelimbs did not. These findings further help explain 1) why younger (including baboons) tend relatively stronger bones than adults, 2) humeri appear weaker femora (in at least baboons). Finally, study demonstrates how field-acquired can answer fundamental biomechanical questions usually addressed animal gait laboratories.