Primate Research Institute, Kyoto University, Inuyama, Japan,
Primate Research Institute, Kyoto University, Inuyama, Japan.
Folia Primatol (Basel). 2021;92(2):79-90. doi: 10.1159/000512901. Epub 2021 Jan 15.
Grooming site preferences have been relatively well studied in monkey species in order to investigate the function of social grooming. They are not only influenced by the amount of ectoparasites, but also by different social variables such as the dominance rank between individuals or their levels of affiliation. However, studies on this topic mainly come from monkey species, with almost no report on great apes. This study aimed to explore whether body site and body orientation preferences during social grooming show species-specific differences (bonobos vs. chimpanzees) and environment-specific differences (captivity vs. wild). Results showed that bonobos groomed the head, the front and faced each other more often than chimpanzees, while chimpanzees groomed the back, anogenitals and more frequently in face-to-back positions. Moreover, captive individuals were found to groom facing one another more often than wild ones, whereas wild individuals groomed the back and in face-to-back positions more. While future studies should expand their scope to include more populations per condition, our preliminary 2 by 2 comparison study highlights the influence of (i) species-specific social differences such as social tolerance, social attention and facial communication, and (ii) socioenvironmental constraints such as risk of predation, spatial crowding and levels of hygiene, that might be the two important factors determining the grooming patterns in two Panspecies.
梳理行为偏好已经在猴类物种中得到了较为充分的研究，以便研究社交梳理的功能。它们不仅受到外寄生虫数量的影响，还受到个体之间的支配等级或从属水平等不同社会变量的影响。然而，关于这个主题的研究主要来自猴类物种，几乎没有关于大型猿类的报道。本研究旨在探索社交梳理过程中身体部位和身体朝向偏好是否表现出物种特异性差异（倭黑猩猩与黑猩猩）和环境特异性差异（圈养与野生）。结果表明，与黑猩猩相比，倭黑猩猩更频繁地梳理头部、正面并彼此面对，而黑猩猩更频繁地梳理背部、肛门生殖器，并更频繁地采用面对面的位置。此外，与野生个体相比，圈养个体更倾向于彼此面对进行梳理，而野生个体更倾向于梳理背部和面对面的位置。虽然未来的研究应该扩大其范围，包括每个条件下更多的群体，但我们初步的 2 乘 2 比较研究强调了（i）物种特异性的社会差异，如社会容忍度、社会关注度和面部交流，以及（ii）社会环境限制，如捕食风险、空间拥挤和卫生水平，这两个因素可能是决定两个 Pan 物种梳理模式的重要因素。
