Researchers in France, Germany and Greece have observed how tree-living (arboreal) mammals, including primates and rodents, move effectively in trees, discovering patterns that provide insight into how primates acquired upright posture.  

Climbing down trees while avoiding falling requires careful management of balance, speed and posture. Animals must adapt their strategy to the arboreal characteristics and their own body measures, such as weight and limb size.  

A research team led by the Center for Research on Paleontology-Paris, France, studied how 57 arboreal animals from 21 species, including primates, rodents, carnivorans, marsupials and tree shrews, climb down trees.  

The researchers found three strategies of descent in living animals — head-first descent, side descent and tail-first descent — and related them to species’ body characteristics, using this information to infer behaviour in fossils related to primate evolution. While non-primates descended mostly head-first, primates used varied strategies, often using side and tail-first descent.  

Co-author Dionisios Youlatos, from the Aristotle University of Thessaloniki, Greece, said: “This marked behavioural divergence highlights the role of evolutionary history and supports recent findings suggesting that shared ecological niches and postural adaptations affect primate locomotion.” 

This study, published in eLife, will also support the improvement of animal welfare in captivity by providing arboreal support fitting the species.