Laterality of tail wrapping in golden snub-nosed monkeys (Rhinopithecus roxellana)

ABSTRACT

Behavioural laterality in nonhuman primates has been commonly studied in paired limb organs, and studies in unpaired organs such as tails are less common. The very limited investigations on tail laterality have focused on New World primates. We firstly investigated the lateral bias of tail wrapping in an Old World primate. From a wild group of one hundred of golden snub-nosed monkeys (Rhinopithecus roxellana), 14 adult monkeys, 7 males and 7 females, were chosen as focus animals. The data of tail wrapping in two different postures that were resting on the ground and climbing the tree trunk were collected and analyzed. The results demonstrated (1) that, when resting on the ground, the focus animals, 3 showed right-side tail-wrapping preference and 11 were ambipreferent; (2) that there was a population-level right tail-wrapping preference in climbing, and 9 of them showed right-side preference, 1 left-side preference and 4 were ambipreferent; (3) and that there were no significant sex differences on the direction and strength of tail wrapping laterality. These findings provide significant evidence for a difference of cerebral asymmetries in tail-wrapping control and would be valuable for further understanding the important function of tails in Old World primates.

KEYWORDS:

• Cerebral asymmetries
• laterality
• tail wrapping
• Rhinopithecus roxellana

Acknowledgements

We thank to the director and staff of Foping tourism administration for their permission to conduct this research. We also thank Dr. Rong Hou for his helpful comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Key Programme of Research and Development, Ministry of Science and Technology [grant number 2016YFC0503200]; the Key Project of Nature Science Function of China [grant number 31730104]; Natural Science Foundation of China [grant numbers 31900338, 32070457, 32000317]; the Key Foundation of Shaanxi Province [grant number 2018ZDXM-NY-049]; Natural Science Foundation of Shaanxi Province [grant number 2019JQ-989] and Shaanxi Academy of Sciences [grant number 2020k-01].