Are larger primates less faunivorous? Consumption of arthropods by Amazonian primates does not fulfil the Jarman-Bell and Kay models

ABSTRACT Terrestrial arthropod groups, including insects, spiders, and millipedes, represent an important food resource for primates. However, species consumed and patterns and rates of arthropod-related feeding for most frugivorous primates are still poorly known. We examined stomach contents of 178 Amazonian primate specimens of nine genera and three families obtained from community-based collections voluntarily donated by subsistence hunters. Based on our results, we assessed whether consumption patterns followed the expected negative relationship between arthropod ingestion and body size as postulated in the Jarman-Bell and Kay models. We identified 12 consumed arthropod taxa, including insects (beetles, grasshoppers, ants, flies, caterpillars, praying mantises, and others), spiders and millipedes. Medium and large-bodied primates consumed a greater diversity (measured by Simpson’s diversity index) and richness of arthropods, but differed in terms of composition of taxa consumed. Cacajao, Sapajus and Cebus consumed proportionally more Orthoptera and Coleoptera compared to the other primate genera analyzed. We did not find significant correlations between richness and diversity of arthropods consumed and primate body mass. There was a slight tendency for the decrease in the relative content of arthropods in the diet with increased body mass in medium and large primates, which does not provide full support for the Jarman-Bell and Kay models. The study of arthropod consumption by arboreal primates in the wild remains challenging. Our study suggests that arthropods supply essential nutrients for frugivorous primates, and provides an alternative method to analyse faunal consumption patterns in primates.

摘要：陆生节肢动物群，包括昆虫、蜘蛛和多足纲动物，对于灵长类动物而言，构成了重要的食物资源。然而，对于大多数果实食性灵长类动物而言，其所消费的物种以及与之相关的节肢动物捕食模式和速率却鲜为人知。本研究通过对来自社区基础收藏自愿捐赠的、来自亚马逊地区的178种灵长类动物样本（九属三科）的胃内容物进行考察，分析了这些物种的饮食习惯。基于研究结果，我们评估了节肢动物摄入量与体型大小之间的预期负相关性是否遵循Jarman-Bell和Kay模型。我们鉴定出12种被摄入的节肢动物类群，包括昆虫（甲虫、蝗虫、蚂蚁、苍蝇、毛毛虫、螳螂等）、蜘蛛和多足纲动物。体型中等到大的灵长类动物消费了更多样化（以辛普森多样性指数衡量）和丰富的节肢动物，但在所消费类群的组成上存在差异。与所分析的其它灵长类属相比，Cacajao、Sapajus和Cebus属的动物按比例消费了更多的直翅目和鞘翅目昆虫。我们没有发现节肢动物丰富度和多样性与其灵长类动物体型质量之间存在显著的相关性。在体型中等到大的灵长类动物中，随着体型的增加，饮食中节肢动物相对含量的降低趋势并不足以完全支持Jarman-Bell和Kay模型。在野外对树栖灵长类动物捕食节肢动物的研究仍然具有挑战性。本研究表明，节肢动物为果实食性灵长类动物提供了必需的营养素，并为分析灵长类动物的食物消费模式提供了一种替代方法。