Behavioural Ecology and Ecophysiology Research Group, Department of Biology, University of Antwerp, Antwerp, Belgium.
Zoo Antwerp Centre for Research and Conservation, Royal Zoological Society of Antwerp, Antwerp, Belgium.
Am J Primatol. 2023 Oct;85(10):e23540. doi: 10.1002/ajp.23540. Epub 2023 Jul 28.
Body condition, a measure for relative fat mass, is associated with primate health, fitness, and overall welfare. Body condition is often influenced by dietary factors, age, and/or sex, but several body condition measures (body weight, weight-to-height ratios, and so on) also show high heritability across primate species, indicating a role of genetic effects. Although different measures for body condition exist, many require direct handling of animals, which is invasive, time-consuming, and expensive, making them impractical in wild and captive settings. Therefore, noninvasive visual body condition score (BCS) systems were developed for various animal species, including macaques and chimpanzees, to visually assess relative fat mass. Here we evaluate the utility of a visual BCS system in bonobos by assessing (1) inter-rater reliability, (2) links with body mass, a traditional hands-on measure of condition, and (3) the factors driving individual variation in BCS. We adapted the chimpanzee BCS system to rate 76 bonobos in 11 European zoos (92% of the adult population). Inter-rater reliability was high (s* = 0.948), BCSs were positively associated with body mass (β = 0.075) and not predicted by diet, sex, or age, nor were they associated with a higher abundance of obesity-related diseases. Instead, BCSs showed high levels of heritability (h = 0.637), indicating that a majority of body condition variation in bonobos is attributable to genetic similarity of the individuals. This is in line with reported h -values for traditional body condition measures in primates and provides support for the reliability of visual BCS systems in great apes. The results of this study emphasize an often unanticipated role of genetics in determining primate body fat and health that has implications for the management of captive primates. Application of this tool in wild populations would aid to unravel environmental from genetic drivers of body condition variation in primates.
体况是衡量相对脂肪量的指标，与灵长类动物的健康、适应性和整体福利有关。体况通常受饮食因素、年龄和/或性别影响，但几种体况衡量标准（体重、体重与身高比等）在灵长类动物物种中也表现出较高的遗传性，表明遗传因素的作用。尽管存在不同的体况衡量标准，但许多标准都需要直接处理动物，这是一种侵入性的、耗时的和昂贵的方法，使其在野外和圈养环境中不切实际。因此，为各种动物物种（包括猕猴和黑猩猩）开发了非侵入性的视觉体况评分（BCS）系统，以视觉评估相对脂肪量。在这里，我们通过评估（1）评分者间的可靠性、（2）与体质量的关系，以及（3）驱动 BCS 个体差异的因素，来评估该系统在倭黑猩猩中的实用性。我们改编了黑猩猩的 BCS 系统，对 11 个欧洲动物园的 76 只倭黑猩猩（成年人口的 92%）进行评分。评分者间的可靠性很高（s*=0.948），BCS 与体质量呈正相关（β=0.075），不受饮食、性别或年龄的影响，也与肥胖相关疾病的发生率增加无关。相反，BCS 显示出较高的遗传力（h=0.637），表明倭黑猩猩的体况变化主要归因于个体间的遗传相似性。这与灵长类动物传统体况衡量标准的报告 h 值一致，并为大型类人猿视觉 BCS 系统的可靠性提供了支持。本研究的结果强调了遗传在决定灵长类动物体脂肪和健康方面的作用，这对圈养灵长类动物的管理具有重要意义。在野外种群中应用这一工具将有助于揭示环境和遗传因素对灵长类动物体况变化的驱动作用。
