Correction: The evolution of vertical climbing in primates: evidence from reaction forces Free

There was an error in J. Exp. Biol. (2017) 220, 3039–3052 (https://doi.org/10.1242/jeb.157628).

During the preparation of the article by Young et al. (2024), discrepancies were identified in the non-human primate single limb forces originally reported by Hanna et al. (2017). Specifically, while Hanna and colleagues documented pulling and pushing normal forces in both the forelimb and hindlimb for all species, Young et al. (2024) exclusively report pulling forces in the forelimb and occasional pulling forces in the hindlimbs of strepsirrhines, with hindlimbs primarily exhibiting pushing forces. The inconsistency in force profiles is attributed to a processing error that was rectified during the reanalysis of these forces.

In essence, the use of poles in the experimental setup for climbing trials introduces a level of freedom, enabling climbing primates to rotate around the pole. Trials where the animal is directly above the force plate provided accurate force readings in biologically relevant planes (e.g. fore–aft forces indicating propulsive and braking forces, normal forces indicating pulling and pushing forces, and mediolateral forces indicating inwardly and outwardly directed forces). However, when the primates moved around the pole, particularly in the mediolateral and normal force planes, these readings no longer accurately reflected the animal's behavior. Care was taken to adjust the directionality and planes of force readings based on the animal's climbing orientation (directly above the force plate with normal forces perpendicular to the substrate or to the left or right of the substrate, where normal forces would register in the mediolateral plane and vice versa). Trials where the animals were in between planes (i.e. diagonally oriented with respect to the substrate) were excluded from analyses. We propose that the pulling (negative) and pushing (positive) normal force profiles reported by Hanna et al. (2017) may include some mediolateral forces, which often vary between medial (negative) and lateral (positive) orientations within a single stride.

We have provided a revised figure (Fig. 1) and tables (Tables 1–3) to present the correct values for climbing (see below). The horizontal climbing data in Hanna et al. (2017) were unaffected by the issue described above. We also note that despite the magnitude differences demonstrated in the revised analysis, this does not alter the overall patterns. Therefore, the interpretation of the data provided by Hanna et al. (2017) remains unchanged.

The authors apologise to the readers for this error, which does not impact the conclusions of the paper.